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Cisco binary image unpacker

2009-11-03T17:46:00.000+07:00

Cisco binary image unpacker is a software that allows you to unpack the IOS and ASA images. Follow this steps to use this software for GNS3. With this way the Router loading process can be faster. This is useful for those of you that do start and stop Router frequently.

Donwload Cisco image unpacker 0.1 for Windows.
Extract thi zip file to your specific folder..
Copy the IOS file to this folder, for example "c3640-jk9s-mz.124-16a.bin".
On windows command prompt, type the following command:
"unpack c3640-jk9s-mz.124-16a.bin" (without "").
The output file stored in temporary folder, in my case "C:\Documents and Settings\dion\Local Settings\Temp".
Open the folder and you will find the unpacked file "C3640-JK.bin", file size is about twofold.
Copy "C3640-JK.bin" to your IOS folder. Your can also rename the file to "c3640-jk9s-mz.124-16a(unpacked).bin"
Open GNS3, On the Edit menu, choose IOS image and hypervisors.
Reset the location of your new unpacked IOS file.

Configuring a Stub Area and a Totally Stubby Area

2009-11-02T10:53:00.000+07:00

Routers Used: 3640 w/ NM-4T

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab, an OSPF stub area and a totally stubby area will be configured.

Scenario

The Semarang router needs to be upgraded as it is suspected that the router is not keeping up with the growth of the OSPF internetwork. Diagnostics are performed and it is discovered that the router could benefit from more memory due to the large routing table. The router could also use a faster processor because of frequent Shortest Path First calculations. It is decided instead to create a smaller and more stable routing table using a stub or totally stubby area configuration.

Step 1

Build and configure the network according to the diagram. Configure multiarea OSPF according to
the diagram. However, do not configure a stub area yet. Use the configuration files from the previous
lab if available and make adjustments as necessary.
Note: The loopback, Lo5, on Jakarta1 can be ignored for now.
Configure each router with the loopback address as indicated in the diagram. Be sure to configure
Jakarta1 with additional loopbacks using Lo0, Lo1, Lo2, and Lo3. These loopback interfaces will
simulate the serial links to other local Jakarta sites.
Use ping and show ip route to test connectivity between all interfaces. Each router should be
able to ping all network interfaces.

Step 2

Create a loopback interface as follows to simulate the serial interface connecting to ISP1:Jakarta1(config)#interface lo5 Jakarta1(config-if)#ip address 10.0.0.6 255.255.255.252
Configure Jakarta1 as follows to redistribute an external route into the OSPF domain:Jakarta1(config)#ip route 10.0.0.0 255.0.0.0 null0 Jakarta1(config)#router ospf 1 Jakarta1(config-router)#redistribute static
Check the routing tables of all three routers. They should be complete.
Jakarta2 and Semarang should also have a Type 2 external route to 10.0.0.0/8. They will not have a specific route to the loopback network, 10.0.0.4/30. That network has not clearly been advertised by any means.

Step 3

Semarang has several interarea (IA) routes and one external (E2) route. In complex OSPF networks,
a large number of external and interarea routes can needlessly weigh down some routers. Semarang
is in a stub area, an area with one egress point. Semarang does not need external routing information, or even interarea summaries. Semarang just needs a default route to the ABR,
Jakarta2.
By configuring Area 2 as a stub area, Jakarta2 automatically produces a default route into Area 2.
Use the following commands to configure the stub area:Jakarta2(config)#router ospf 1 Jakarta2(config-router)#area 2 stub
Also configure Semarang as follows:Semarang(config)#router ospf 1 Semarang(config-router)#area 2 stub
Verify that Area 2 is a stub by issuing the show ip ospf command:
Now check Semarang’s routing table. Notice that a default route, 0.0.0.0/0, has been generated by the ABR, Jakarta2, on the stub area and now appears in Semarang’s table.

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Recall that interarea (IA) routes point to networks in different areas within the same OSPF autonomous system.
Because Area 2 is a stub area, all external routes, Type 5 LSAs, have been prevented from reaching
internal routers.
All external routes are filtered from stub areas and are replaced with a default route.

Step 4

It is decided that the stub area configuration is not making a substantial impact on Area 2. Because Semarang can use the default route to its ABR for all nonlocal area traffic, it is decided to filter Type 3 and Type 4 interarea routes from Area 2. To do this, Area 2 must be configured as a totally stubby area, which is a Cisco proprietary feature.
Use the following commands on Jakarta2, the ABR, to configure Area 2 as a totally stubby area:Jakarta2(config)#router ospf 1 Jakarta2(config-router)#no area 2 stub Jakarta2(config-router)#area 2 stub no-summary
The no-summary keyword at the ABR keeps interarea routes from entering stub Area 2, creating a
totally stubby area. Only the ABR needs the additional configuration. The role of Area 2 internal
routers has not changed.
Return to Semarang and check its routing table:
Interarea routes have also been replaced by a default route.
Semarang should get a positive response by forwarding ICMP requests to Jakarta2 using the
default route 0.0.0.0/0. Jakarta2 has a default route to network 10.0.0.0/8, and Jakarta1 has a
directly connected route to 10.0.0.4/30 with the loopback interface 10.0.0.6/30.

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Configuring a Stub Area and a Totally Stubby Area

Configuring Point-to-Multipoint OSPF Over Frame Relay

2009-10-28T10:44:00.002+07:00

Routers Used: 3640 w/ NM-4T

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab, configure OSPF as a point-to-multipoint network type so that it operates efficiently over a hub-and-spoke Frame Relay topology.

Scenario

International Travel Agency has just connected two regional headquarters to Asterix using Frame Relay in a hub-and-spoke topology. OSPF routing is to be configured over this type of network, which is known for introducing complications into OSPF adjacency relationships. To avoid these complications, manually override the Non-Broadcast Multi-Access (NBMA) OSPF network type and configure OSPF to run as a point-to-multipoint network. In this environment, no DR or BDR is elected.

Step 1

Cable the network according to the diagram. Configure the FastEthernet or Loopback interface for each router as shown, but leave the serial interfaces and OSPF routing unconfigured for now.
Until Frame Relay is configured, ping is not useful for testing connectivity.
Configure port number and DLCI for the Frame Relay Switch Real seen in the picture.

Step 2

Asterix acts as the hub in this hub-and-spoke network. It reaches Surabaya and Tegal through two separate PVCs. Configure Frame Relay on Asterix’s serial interface shown as follows:
Asterix(config)#interface serial 0/0 Asterix(config-if)#encapsulation frame-relay Asterix(config-if)#ip address 192.168.192.1 255.255.255.0 Asterix(config-if)#no shutdown Asterix(config-if)#frame-relay map ip 192.168.192.2 102 broadcast Asterix(config-if)#frame-relay map ip 192.168.192.4 103 broadcast Asterix(config-if)#ip ospf network point-to-multipoint
Notice that this configuration includes frame-relay map commands, which are also used on multipoint Frame Relay subinterfaces. These commands are used here with the broadcast keyword so that Frame Relay can process broadcast traffic. Without this configuration, OSPF multicast traffic would not be forwarded correctly by the Asterix router.
Configure the serial interface for Surabaya as follows:Surabaya(config)#interface serial 0/0 Surabaya(config-if)#encapsulation frame-relay Surabaya(config-if)#ip address 192.168.192.2 255.255.255.0 Surabaya(config-if)#no shutdown Surabaya(config-if)#frame-relay map ip 192.168.192.1 201 broadcast Surabaya(config-if)#frame-relay map ip 192.168.192.4 201 broadcast Surabaya(config-if)#ip ospf network point-to-multipoint
Finally, configure the serial interface for Tegal as follows:Tegal(config)#interface serial 0/0Tegal(config-if)#encapsulation frame-relayTegal(config-if)#ip address 192.168.192.4 255.255.255.0Tegal(config-if)#no shutdownTegal(config-if)#frame-relay map ip 192.168.192.1 301 broadcastTegal(config-if)#frame-relay map ip 192.168.192.2 301 broadcastTegal(config-if)#ip ospf network point-to-multipoint
Verify Frame Relay operation with a ping command from each router to the other two. Use show frame-relay pvc and show frame-relay map to troubleshoot connectivity problems. Rebooting the Frame Relay switch might also solve connectivity issues.

Step 3

Configure OSPF to run over this point-to-multipoint network. Issue the following commands at the appropriate router:Surabaya(config)#router ospf 1 Surabaya(config-router)#network 192.168.200.0 0.0.0.255 area 0 Surabaya(config-router)#network 192.168.192.0 0.0.0.255 area 0 Asterix(config)#router ospf 1 Asterix(config-router)#network 192.168.1.0 0.0.0.255 area 0 Asterix(config-router)#network 192.168.192 0.0.0.255 area 0 Tegal(config)#router ospf 1 Tegalrouter)#network 192.168.232.0 0.0.0.255 area 0 Tegal(config-router)#network 192.168.192.0 0.0.0.255 area 0
Verify the OSPF configuration by issuing the show ip route command at each of the routers:

If each router has a complete table, including routes to 192.168.1.0 /24, 192.168.200.0 /24, and 192.168.232.0 /24, OSPF has been successfully configured to operate over Frame Relay.
Test these routes by pinging the FastEthernet interfaces of each router from Surabaya’s console.
Finally, issue the show ip ospf neighbor detail command at any router console:
There is no DR. The configuration of OSPF point-to-multipoint network type on serial interfaces creates a logical multi-access network over physical point-to-point links. No efficiency would be realized by electing a DR.

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Configuring Point-to-Multipoint OSPF Over Frame Relay

Configuring Multiarea OSPF

2009-08-13T16:53:00.005+07:00

Routers Used: 3640 w/ NM-1FE-TX

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab configure a multiarea OSPF operation, interarea summarization, external route
summarization, and default routing.

Scenario

International Travel Agency (ITA) maintains a complex OSPF environment. The task is to optimize OSPF routing, which creates the need to design and configure multiarea OSPF on the key routers connecting Asian regional headquarters to Asterix corporate headquarters and its local sites.

Step 1

Build and configure the network according to the diagram, but do not configure a routing protocol yet.
Note: Ignore the ISP cloud for now. Also, the Dion-to-Tegal networks
192.168.240.0/24, 192.168.244.0/244, 192.168.248.0/24, and 192.168.252.0/24 will be
configured as static routes to Null0 in Steps 5 and 6, so should be deferred until then.
Configure each router with the loopback address indicated in the diagram. Be sure to configure Asterix1 with additional loopbacks of Lo0, Lo1, Lo2, and Lo3. These loopback interfaces simulate the serial links to local Asterix sites: Air, Bumi, Udara, and Api.
Use ping to test connectivity between all interfaces. Each router should be able to ping its link partner.

Step 2

Configure multiarea OSPF. On Asterix1, configure FastEthernet 0/0 as a member of Area0 and all other interfaces as members of Area 1 by using the following commands:Asterix1(config)#router ospf 1Asterix1(config-router)#network 192.168.1.0 0.0.0.255 area 0Asterix1(config-router)#network 192.168.64.0 0.0.63.255 area 1
The last command conveniently enables all loopback interfaces on Asterix1 to participate in the OSPF process.
On Asterix3, configure E0 and Lo0 as members of Area 0, but configure Serial 1/0 as part of Area 51 as follows:Asterix3(config)#router ospf 1 Asterix3(config-router)#network 192.168.1.0 0.0.0.255 area 0 Asterix3(config-router)#network 192.168.224.0 0.0.0.3 area 51 Asterix3(config-router)#network 192.168.3.0 0.0.0.255 area 0
Finally, on Dion, configure Serial 0/0 to belong to Area 51 as follows:Dion(config)#router ospf 1 Dion(config-router)#network 192.168.224.0 0.0.0.3 area 51
Issue the show ip ospf command as follows on all three routers:Asterix3#sh ip ospf Routing Process "ospf 1" with ID 192.168.3.1 Start time: 00:21:08.924, Time elapsed: 00:22:46.708 Supports only single TOS(TOS0) routes Supports opaque LSA Supports Link-local Signaling (LLS) Supports area transit capability It is an area border router Router is not originating router-LSAs with maximum metric Initial SPF schedule delay 5000 msecs Minimum hold time between two consecutive SPFs 10000 msecs Maximum wait time between two consecutive SPFs 10000 msecs Incremental-SPF disabled Minimum LSA interval 5 secs Minimum LSA arrival 1000 msecs LSA group pacing timer 240 secs Interface flood pacing timer 33 msecs Retransmission pacing timer 66 msecs Number of external LSA 0. Checksum Sum 0x000000 Number of opaque AS LSA 0. Checksum Sum 0x000000 Number of DCbitless external and opaque AS LSA 0 Number of DoNotAge external and opaque AS LSA 0 Number of areas in this router is 2. 2 normal 0 stub 0 nssa Number of areas transit capable is 0 External flood list length 0 Area BACKBONE(0) Number of interfaces in this area is 2 (1 loopback) Area has no authentication SPF algorithm last executed 00:22:10.488 ago SPF algorithm executed 4 times Area ranges are Number of LSA 8. Checksum Sum 0x0417F3 Number of opaque link LSA 0. Checksum Sum 0x000000 Number of DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0 Area 51 Number of interfaces in this area is 1 Area has no authentication SPF algorithm last executed 00:19:09.432 ago SPF algorithm executed 4 times Area ranges are Number of LSA 8. Checksum Sum 0x04AB35 Number of opaque link LSA 0. Checksum Sum 0x000000 Number of DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0
Area border routers connect one or more adjacent OSPF areas to the backbone area.
Autonomous system border routers connect external, non-OSPF, networks to the OSPF
internetwork.
Issue the show ip ospf neighbor detail command on Asterix3:
Asterix3#show ip ospf neighbor detail
Neighbor 192.168.112.1, interface address 192.168.1.1
In the area 0 via interface FastEthernet0/0
Neighbor priority is 1, State is FULL, 6 state changes
DR is 192.168.1.1 BDR is 192.168.1.3
Options is 0x52
LLS Options is 0x1 (LR)
Dead timer due in 00:00:32
Neighbor is up for 00:35:57
Index 1/1, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum is 0 msec
Neighbor 192.168.224.2, interface address 192.168.224.2
In the area 51 via interface Serial1/0
Neighbor priority is 0, State is FULL, 6 state changes
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x52
LLS Options is 0x1 (LR)
Dead timer due in 00:00:38
Neighbor is up for 00:32:51
Index 1/2, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum is 0 msec
These are different types of OSPF networks. The Ethernet core network is designated as
“broadcast”, and the WAN link between Asterix3 and Dion is designated “point-to-point”. On a point-to-point link, there is no need to elect a DR to reduce the number of adjacencies, because only two routers exist in the network. The Ethernet segment has only two routers. However, a DR and BDR are elected because neighbor routers could join the area.

Step 3

Check the routing table on each router. The output should show OSPF inter-area routes, which are denoted by an O and other routes denoted by an IA.Dion#sh ip route Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route Gateway of last resort is not set 192.168.224.0/30 is subnetted, 1 subnets C 192.168.224.0 is directly connected, Serial0/0 192.168.64.0/32 is subnetted, 1 subnets O IA 192.168.64.1 [110/66] via 192.168.224.1, 01:13:52, Serial0/0 192.168.80.0/32 is subnetted, 1 subnets O IA 192.168.80.1 [110/66] via 192.168.224.1, 01:13:52, Serial0/0 192.168.96.0/32 is subnetted, 1 subnets O IA 192.168.96.1 [110/66] via 192.168.224.1, 01:13:52, Serial0/0 192.168.112.0/32 is subnetted, 1 subnets O IA 192.168.112.1 [110/66] via 192.168.224.1, 01:13:52, Serial0/0 O IA 192.168.1.0/24 [110/65] via 192.168.224.1, 01:13:52, Serial0/0 192.168.3.0/32 is subnetted, 1 subnets O IA 192.168.3.1 [110/65] via 192.168.224.1, 01:13:52, Serial0/0
Check the codes listed with the routing table. Interarea routes point to networks in separate areas within the same OSPF autonomous system.
Verify that the routing tables are complete. Notice that Asterix1’s loopback interfaces appear in the other routing tables of other routers that have a 32-bit mask. Any route with a 32-bit mask is called a ‘host route’, because it is a route to a host, not to a network. OSPF does not advertise loopback interfaces as if they were connected to a network.
There should be a host route for every remote loopback advertised through OSPF.
Verify connectivity. From Dion, ping Asterix3’s Lo0 interface (192.168.3.1) and Asterix1’s Lo2 interface (192.168.96.1).

Step 4

To reduce routing table entries it is necessary to implement interarea route summarization
throughout the internetwork. Start by configuring Asterix1 to summarize the networks for Area 1 and advertise this summary route to Area 0.
On Asterix1, enter the following commands to perform interarea summarization:
Asterix1(config)#router ospf 1
Asterix1(config-router)#area 1 range 192.168.64.0 255.255.192.0
When finished configuring the summary address, check the routing tables of Asterix3 and
Dion. If the expected changes do not occur, save and reload the routers.Dion# sh ip route (output omitted) 192.168.224.0/30 is subnetted, 1 subnets C 192.168.224.0 is directly connected, Serial0/0 O IA 192.168.1.0/24 [110/65] via 192.168.224.1, 01:25:27, Serial0/0 192.168.3.0/32 is subnetted, 1 subnets O IA 192.168.3.1 [110/65] via 192.168.224.1, 01:25:27, Serial0/0 O IA 192.168.64.0/18 [110/66] via 192.168.224.1, 00:05:35, Serial0/0
Dion should have only one host route of 192.168.3.1/32 from Asterix3 Lo0. A host route
points to one host. A network route points to multiple hosts in one broadcast domain. A summarized route points to a numerically contiguous series of networks.

Step 5

Dion must be configured to redistribute external routes from Tegal into the OSPF
autonomous system. For the purposes of this lab, simulate the Tegal connection by configuring a static route in Dion to the Tegal LAN (192.168.248.0/24). Use the following commands:Dion(config)#ip route 192.168.248.0 255.255.255.0 null0 Dion(config)#router ospf 1 Dion(config-router)#redistribute static
Because the route to 192.168.248.0/24 is imaginary, null0 is used as the exit interface. The
redistribute command imports the static route into OSPF. Routes originated from anything but OSPF are considered external to the OSPF database. By default, when Dion redistributes into Area 51, it creates and advertises Type 2 (E2) external routes using Type 5 LSAs.
The use of static routes to a null interface is a commonly used routing trick. Typically this technique is used to initialize or advertise a supernet route so that packets destined to an unknown subnet of a classful network are forwarded to ‘this’ router for handling. This technique is particularly useful when configuring Border Gateway Protocol (BGP).
Issue the show ip ospf command on Dion.Dion#sh ip ospf Routing Process "ospf 1" with ID 192.168.224.2 Start time: 00:23:51.652, Time elapsed: 01:34:33.864 Supports only single TOS(TOS0) routes Supports opaque LSA Supports Link-local Signaling (LLS) Supports area transit capability It is an autonomous system boundary router Redistributing External Routes from, static Router is not originating router-LSAs with maximum metric Initial SPF schedule delay 5000 msecs Minimum hold time between two consecutive SPFs 10000 msecs Maximum wait time between two consecutive SPFs 10000 msecs Incremental-SPF disabled Minimum LSA interval 5 secs Minimum LSA arrival 1000 msecs LSA group pacing timer 240 secs Interface flood pacing timer 33 msecs Retransmission pacing timer 66 msecs Number of external LSA 1. Checksum Sum 0x0045AC Number of opaque AS LSA 0. Checksum Sum 0x000000 Number of DCbitless external and opaque AS LSA 0 Number of DoNotAge external and opaque AS LSA 0 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Number of areas transit capable is 0 External flood list length 0 Area 51 Number of interfaces in this area is 1 Area has no authentication SPF algorithm last executed 00:02:18.184 ago SPF algorithm executed 3 times Area ranges are Number of LSA 5. Checksum Sum 0x02AA64 Number of opaque link LSA 0. Checksum Sum 0x000000 Number of DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0
Recall that ASBRs connect external networks to the OSPF autonomous system.
Now check the routing table of Asterix1. The routing table should have an E2 route to
192.168.248.0/24.Asterix1#sh ip route (output omitted) 192.168.224.0/30 is subnetted, 1 subnets O IA 192.168.224.0 [110/65] via 192.168.1.3, 00:16:06, FastEthernet0/0 C 192.168.64.0/24 is directly connected, Loopback0 C 192.168.80.0/24 is directly connected, Loopback1 10.0.0.0/30 is subnetted, 1 subnets C 10.0.0.4 is directly connected, Loopback5 C 192.168.96.0/24 is directly connected, Loopback2 O E2 192.168.248.0/24 [110/20] via 192.168.1.3, 00:04:36, FastEthernet0/0 C 192.168.112.0/24 is directly connected, Loopback3 C 192.168.1.0/24 is directly connected, FastEthernet0/0 192.168.3.0/32 is subnetted, 1 subnets O 192.168.3.1 [110/2] via 192.168.1.3, 00:16:06, FastEthernet0/0 O 192.168.64.0/18 is a summary, 00:16:06, Null0
Check the routing table of Asterix3. This router should also have the external route.
Asterix1 and Asterix3 should have the same cost. This might be surprising, because Asterix1 has an additional network to traverse.
A second link to the external network is about to come online. If the network is designed so that OSPF routers can have multiple external routes to the same destination, consider using Type 1 (E1) external routes. Type 2 (E2) external routes have static metrics throughout the OSPF autonomous system (AS). Type 1 routes consider metrics internal and external to the AS for accurate route selection when multiple external routes exist. The decision is made that Dion should advertise external routes as Type 1 (E1). To configure Type 1, use the following commands on Dion:Dion(config)#router ospf 1 Dion(config-router)#redistribute static metric-type 1
After reconfiguring Dion, check Asterix3’s table again. Asterix3’s route to 192.168.248.0/24 should now be Serial 1/0.
Typically, the cost of a route increases with every hop. Type2 (E2) routes ignore internal OSPF metrics. Type1 (E1) routes accumulate costs while being produced through the OSPF AS. With one exit point for the AS, Type2 (E2) routes might be adequate.

Step 6

Over time, notice that as the Tegal office grows, many more Type 1, or FastEthernet 0/1, networks are propagated through the internetwork. To optimize the internetwork by reducing the routing table size, implement Classless Interdomain Routing (CIDR) to advertise all Tegal networks with one route. Create routes to these Tegal networks with three more static routes as follows:Dion(config)#ip route 192.168.240.0 255.255.255.0 null0 Dion(config)#ip route 192.168.244.0 255.255.255.0 null0 Dion(config)#ip route 192.168.252.0 255.255.255.0 null0
Configure Dion to advertise all Tegal networks with a summary route:Dion(config)#router ospf 1 Dion(config-router)#sum Dion(config-router)#summary-address 192.168.240.0 255.255.240.0
After configuring the summary, check the routing tables on Asterix1 and Asterix3. Both routers should receive and install the supernet route, 192.168.240.0/20.
Note: On routers with very large routing tables the command show ip route supernet will show only aggregate routes.Asterix3#show ip route (output omitted) 192.168.224.0/30 is subnetted, 1 subnets C 192.168.224.0 is directly connected, Serial1/0 C 192.168.1.0/24 is directly connected, FastEthernet0/0 C 192.168.3.0/24 is directly connected, Loopback0 O E1 192.168.240.0/20 [110/84] via 192.168.224.2, 00:15:32, Serial1/0 O IA 192.168.64.0/18 [110/2] via 192.168.1.1, 00:41:40, FastEthernet0/0 Asterix1#show ip route supernet (output omitted) O E1 192.168.240.0/20 [110/85] via 192.168.1.3, 00:20:58, FastEthernet0/0 O 192.168.64.0/18 is a summary, 00:58:30, Null0
Is 192.168.248.0/24 still in Asterix1 or Asterix3’s routing table? It should not be present because 192.168.248.0/24 is included in the range 192.168.240.0/20.
Internet connectivity is by way of ISP through Asterix1. The link is not active yet, but OSPF is configured in advance. Simulate the link with a loopback interface as follows:Asterix1(config)#interface lo5 Asterix1(config-if)#ip address 10.0.0.6 255.255.255.252
Use the following commands to create and advertise a default route on Asterix1:Asterix1(config)#router ospf 1 Asterix1(config-router)#default-information originate always
The always keyword instructs OSPF to advertise the default route whether or not the router has one in the routing table. In this case, the router will install a gateway of last resort as displayed in the output. Check the routing tables on Asterix3 and Dion. Both should now have a default route of 0.0.0.0/0.Asterix3#show ip route (output omitted) Gateway of last resort is 192.168.1.1 to network 0.0.0.0 192.168.224.0/30 is subnetted, 1 subnets C 192.168.224.0 is directly connected, Serial1/0 C 192.168.1.0/24 is directly connected, FastEthernet0/0 C 192.168.3.0/24 is directly connected, Loopback0 O*E2 0.0.0.0/0 [110/1] via 192.168.1.1, 00:01:28, FastEthernet0/0 O E1 192.168.240.0/20 [110/84] via 192.168.224.2, 00:01:28, Serial1/0 O IA 192.168.64.0/18 [110/2] via 192.168.1.1, 00:01:28, FastEthernet0/0
The default route is considered External Type2 (E2). The default cost of one (1) will be retained throughout the autonomous system.
Verify that default routing is working by asking Dion to ping a host that is not represented in its routing table. From Dion, ping 10.0.0.6. If the default route is working, Dion should receive replies. Troubleshoot, if necessary.

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Configuring Multiarea OSPF

Examining the DR/BDR Election Process

2009-08-13T10:54:00.008+07:00

Routers Used: 3640 w/ NM-1FE-TX

IOS: c3640-jk9s-mz.124-16a

Objective:

In this lab, observe the OSPF DR and BDR election processing using debug commands. Then assign each OSPF interface a priority value to force the election of a specific router as a DR.

Scenario

The backbone of International Travel Agency’s enterprise network consists of three routers connected using an Ethernet core. Asterix1 has more memory and processing power than the other core routers. Unfortunately, other core routers are continually elected as the DR under the default settings. In the interest of optimization, ensure that Asterix1 is elected the DR, because it is best suited to handle associated extra duties, including management of Link State Advertisements (LSA) for Area 0. Investigate and correct this situation.

Step 1

Build and configure the network according to the diagram. Use the configuration files from the previous lab if available. Configure OSPF on all Ethernet interfaces. A switch or hub is required to connect the three routers through Ethernet. Be sure to configure each router with the loopback interface and IP address shown in the diagram.
Use ping to verify the work and test connectivity between the Ethernet interfaces.

Step 2

Use the show ip ospf neighbor detail command as follows to verify that the OSPF routers have formed adjacencies:
Note: The routers are still using authentication for the previous lab setup.
Asterix3#sh ip ospf neighbor detail Neighbor 192.168.31.11, interface address 192.168.1.1 In the area 0 via interface FastEthernet0/0 Neighbor priority is 1, State is FULL, 6 state changes DR is 192.168.1.3 BDR is 192.168.1.2 Options is 0x52 LLS Options is 0x1 (LR) Dead timer due in 00:00:16 Neighbor is up for 00:00:43 Index 1/1, retransmission queue length 0, number of retransmission 0 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 0, maximum is 0 Last retransmission scan time is 0 msec, maximum is 0 msec Neighbor 192.168.31.22, interface address 192.168.1.2 In the area 0 via interface FastEthernet0/0 Neighbor priority is 1, State is FULL, 6 state changes DR is 192.168.1.3 BDR is 192.168.1.2 Options is 0x52 LLS Options is 0x1 (LR) Dead timer due in 00:00:15 Neighbor is up for 00:00:44 Index 2/2, retransmission queue length 0, number of retransmission 0 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 0, maximum is 0 Last retransmission scan time is 0 msec, maximum is 0 msec
Recall that router IDs determine the DR and BDR.

Step 3

If the network is configured according to the diagram, Asterix1 will not be the DR. Temporarily shutdown Asterix3, which has the highest router ID, 192.168.31.33, and observe the DR/BDR election process. To observe the election, issue the following debug command on Asterix1:
Asterix1#debug ip ospf adj
Now that OSPF adjacency events will be logged to Asterix1 console, remove Asterix3 from the OSPF network by shutting down its FastEthernet interface as follows:
Asterix3(config)#interface fastethernet 0/0 Asterix3(config-if)#shutdown Asterix1# *Mar 1 00:18:09.787: OSPF: 192.168.31.33 address 192.168.1.3 on FastEthernet0/0 is dead *Mar 1 00:18:09.787: OSPF: 192.168.31.33 address 192.168.1.3 on FastEthernet0/0 is dead, state DOWN *Mar 1 00:18:09.791: %OSPF-5-ADJCHG: Process 1, Nbr 192.168.31.33 on FastEthern et0/0 from FULL to DOWN, Neighbor Down: Dead timer expired *Mar 1 00:18:09.795: OSPF: Neighbor change Event on interface FastEthernet0/0 *Mar 1 00:18:09.799: OSPF: DR/BDR election on FastEthernet0/0 *Mar 1 00:18:09.799: OSPF: Elect BDR 192.168.31.22 *Mar 1 00:18:09.803: OSPF: Elect DR 192.168.31.22 *Mar 1 00:18:09.803: DR: 192.168.31.22 (Id) BDR: 192.168.31.22 (Id) *Mar 1 00:18:09.807: OSPF: Remember old DR 192.168.31.33 (id) *Mar 1 00:18:09.867: OSPF: Neighbor change Event on interface FastEthernet0/0 *Mar 1 00:18:09.871: OSPF: DR/BDR election on FastEthernet0/0 *Mar 1 00:18:09.871: OSPF: Elect BDR 192.168.31.11 *Mar 1 00:18:09.875: OSPF: Elect DR 192.168.31.22 Asterix1# *Mar 1 00:18:09.875: OSPF: Elect BDR 192.168.31.11 *Mar 1 00:18:09.879: OSPF: Elect DR 192.168.31.22 *Mar 1 00:18:09.879: DR: 192.168.31.22 (Id) BDR: 192.168.31.11 (Id)
The former BDR is promoted to DR.
In the debug output, look for a statement about remembering the “old DR”. Unless Asterix1 and Asterix2 are powered off, they will remember that Asterix3 was the old DR. When Asterix3 comes back online, these routers will allow Aserix3 to reassume its role as DR.

Step 4

At this point, Asterix1 should have assumed the role of BDR. Bring Asterix3 back online, and observe the new election process.
Asterix1 remains the BDR even though Asterix2 has the higher router ID.

Step 5

A router can be manipulated to become the DR by using two methods. The router ID could be changed to a higher number, but that could confuse the loopback addressing system and affect elections on other interfaces. The same router ID is used for every network that a router is a member of. For example, if an OSPF router has an exceptionally high router ID, it could win the election on every multiaccess interface and, as a result, do triple or quadruple duty as a DR.
Instead of reconfiguring router IDs, manipulate the election by configuring OSPF priority values. Because priorities are an interface-specific value, they provide finer control of the OSPF internetwork by allowing a router to be the DR in one network and a DRother in another. Priority values are the first consideration in the DR election, with the highest priority winning. Values can range from 0 to 255. A value of 0 indicates that the interface will not participate in an election. Use the show ip ospf interface command as follows to examine the current priority values of the Ethernet interfaces on the three routers:
Asterix1#sh ip ospf interface FastEthernet0/0 is up, line protocol is up Internet Address 192.168.1.1/24, Area 0 Process ID 1, Router ID 192.168.31.11, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State BDR, Priority 1 Designated Router (ID) 192.168.31.22, Interface address 192.168.1.2 Backup Designated router (ID) 192.168.31.11, Interface address 192.168.1.1 Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:03 Supports Link-local Signaling (LLS) Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 0, maximum is 1 Last flood scan time is 4 msec, maximum is 4 msec Neighbor Count is 2, Adjacent neighbor count is 2 Adjacent with neighbor 192.168.31.22 (Designated Router) Adjacent with neighbor 192.168.31.33 Suppress hello for 0 neighbor(s) Message digest authentication enabled Youngest key id is 1
The default priority is one (1). Because all have equal priority, router ID is used to determine the DR and BDR.
Modify the priority values so that Asterix1 will become the DR and Asterix2 will become the BDR, regardless of their router ID. Use the following commands:Asterix1(config)#interface fastethernet 0/0 Asterix1(config-if)#ip ospf priority 200 Asterix2(config)#interface fastethernet 0/0 Asterix2(config-if)#ip ospf priority 100
In order to reset the election process, write the configuration for each router to NVRAM and reload Asterix1, Asterix2, and Asterix3. Issue the following command at each router:Asterix1#copy running-config startup-config
To reload all routers use stop and start buttons in GNS3 or use the following command in GNS3 Console:=> reload /all
When the routers finish reloading, try to observe the OSPF election on Asterix1 by using the debug ip ospf adj command. Also, verify the configuration by issuing the show ip ospf interface command at both Asterix1 and Asterix2.Asterix1#debug ip ospf adj OSPF adjacency events debugging is on Asterix1# *Mar 1 00:00:42.027: OSPF: Neighbor change Event on interface FastEthernet0/0 *Mar 1 00:00:42.031: OSPF: DR/BDR election on FastEthernet0/0 *Mar 1 00:00:42.031: OSPF: Elect BDR 192.168.31.22 *Mar 1 00:00:42.035: OSPF: Elect DR 192.168.31.11 *Mar 1 00:00:42.035: DR: 192.168.31.11 (Id) BDR: 192.168.31.22 (Id) Asterix2#sh ip ospf interface FastEthernet0/0 is up, line protocol is up Internet Address 192.168.1.2/24, Area 0 Process ID 1, Router ID 192.168.31.22, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State BDR, Priority 100 Designated Router (ID) 192.168.31.11, Interface address 192.168.1.1 Backup Designated router (ID) 192.168.31.22, Interface address 192.168.1.2 Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:02 Supports Link-local Signaling (LLS) Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 0, maximum is 1 Last flood scan time is 0 msec, maximum is 4 msec Neighbor Count is 2, Adjacent neighbor count is 2 Adjacent with neighbor 192.168.31.11 (Designated Router) Adjacent with neighbor 192.168.31.33 Suppress hello for 0 neighbor(s) Message digest authentication enabled Youngest key id is 1
After the election is complete, verify that Asterix1 and Asterix2 have assumed the correct roles by using the show ip ospf neighbor detail command. Troubleshoot, if necessary.Asterix3#show ip ospf neighbor detail Neighbor 192.168.31.11, interface address 192.168.1.1 In the area 0 via interface FastEthernet0/0 Neighbor priority is 200, State is FULL, 6 state changes DR is 192.168.1.1 BDR is 192.168.1.2 Options is 0x52 LLS Options is 0x1 (LR) Dead timer due in 00:00:17 Neighbor is up for 00:04:07 Index 1/1, retransmission queue length 0, number of retransmission 1 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 1, maximum is 1 Last retransmission scan time is 0 msec, maximum is 0 msec Neighbor 192.168.31.22, interface address 192.168.1.2 In the area 0 via interface FastEthernet0/0 Neighbor priority is 100, State is FULL, 6 state changes DR is 192.168.1.1 BDR is 192.168.1.2 Options is 0x52 LLS Options is 0x1 (LR) Dead timer due in 00:00:17 Neighbor is up for 00:04:07 Index 2/2, retransmission queue length 0, number of retransmission 0 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 0, maximum is 0 Last retransmission scan time is 0 msec, maximum is 0 msec
Note that the order in which routers join an area can have the most significant effect on which routers are elected as DR and BDR. An election is necessary only when a DR or BDR does not exist in the network. As a router starts its OSPF process, it checks the network for an active DR and BDR. If they exist, the new router becomes a DRother, regardless of its priority or router ID. Remember, the roles of DR and BDR were created for efficiency. New routers in the network should not force an election when adjacencies are already optimized. However, there is an exception. A known bug in some IOS versions allows a ’new’ router with higher election credentials to force an election and assume the role of DR.

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Examining the DR/BDR Election Process

Configuring OSPF

2009-06-11T10:18:00.003+07:00

Routers Used: 3640 w/ NM-1FE-TX

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab, OSPF will be configured on three Cisco routers. First, configure loopback interfaces to provide stable OSPF Router IDs. Then configure the OSPF process and enable OSPF on the appropriate interfaces. After OSPF is enabled, tune the update timers and configure authentication.

Scenario

The backbone of International Travel Agency’s (ITA) WAN, located in Jakarta, consists of three routers connected using an Ethernet core. Configure these core routers as members of OSPF Area 0. Because the core routers are connected to the Internet, it is decided to implement security, preventing unauthorized routers from joining Area 0. Also, within the core, the network failures need to be realized quickly.

Step 1

Build and configure the network according to the diagram, but do not configure OSPF yet. A switch or hub is required to connect the three routers through Ethernet.
Use ping to verify the work and test connectivity between the FastEthernet interfaces.

Step 2

On each router, configure a loopback interface with a unique IP address. Cisco routers use the highest loopback IP address as the OSPF Router ID. In the absence of a loopback interface, the router uses the highest IP address among its active interfaces, which might force a router to change router IDs if an interface goes down. Because loopback interfaces are immune to physical and data link problems, they should be used to derive the router ID. To avoid conflicts with registered network addresses, use private network ranges for the loopback interfaces. Configure the core routers using the following commands:
Asterix1(config)#interface loopback 0 Asterix1(config-if)#ip address 192.168.31.11 255.255.255.255 Asterix2(config)#interface loopback 0 Asterix2(config-if)#ip address 192.168.31.22 255.255.255.255 Asterix3(config)#interface loopback 0 Asterix3(config-if)#ip address 192.168.31.33 255.255.255.255

Step 3

Now that loopback interfaces are configured, configure OSPF. Use the following commands as an example to configure each router:
Asterix1(config)#router ospf 1 Asterix1(config-router)#network 192.168.1.0 0.0.0.255 area 0
Note: An OSPF process ID is locally significant. It does not need to match neighboring
routers. The ID is needed to identify a unique instance of an OSPF database, because
multiple processes can run concurrently on a single router.

Step 4

After enabling OSPF routing on each of the three routers, verify its operation using show commands. Several important show commands can be used to gather OSPF information. First, issue the show ip protocols command on any of the three routers, as follows:
Asterix1#show ip protocols Routing Protocol is "ospf 1" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Router ID 192.168.31.11 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Maximum path: 4 Routing for Networks: 192.168.1.0 0.0.0.255 area 0 Reference bandwidth unit is 100 mbps Routing Information Sources: Gateway Distance Last Update Distance: (default is 110)
Next, use the show ip ospf command, as follows, to get more details about the OSPF
process.
Asterix1#show ip ospf Routing Process "ospf 1" with ID 192.168.31.11 Start time: 00:28:45.292, Time elapsed: 00:04:36.424 Supports only single TOS(TOS0) routes Supports opaque LSA Supports Link-local Signaling (LLS) Supports area transit capability Router is not originating router-LSAs with maximum metric Initial SPF schedule delay 5000 msecs Minimum hold time between two consecutive SPFs 10000 msecs Maximum wait time between two consecutive SPFs 10000 msecs Incremental-SPF disabled Minimum LSA interval 5 secs Minimum LSA arrival 1000 msecs LSA group pacing timer 240 secs Interface flood pacing timer 33 msecs Retransmission pacing timer 66 msecs Number of external LSA 0. Checksum Sum 0x000000 Number of opaque AS LSA 0. Checksum Sum 0x000000 Number of DCbitless external and opaque AS LSA 0 Number of DoNotAge external and opaque AS LSA 0 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Number of areas transit capable is 0 External flood list length 0 Area BACKBONE(0) Number of interfaces in this area is 1 Area has no authentication SPF algorithm last executed 00:02:40.240 ago SPF algorithm executed 3 times Area ranges are Number of LSA 4. Checksum Sum 0x01D2C0 Number of opaque link LSA 0. Checksum Sum 0x000000 Number of DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0
The loopback interface should be seen as the router ID. To see the OSPF neighbors, use the show ip ospf neighbor command. The output of this command displays all known OSPF neighbors, including their router IDs, their interface addresses, and their adjacency status. Also issue the show ip ospf neighbor detail command, which outputs even more information as follows:
Asterix1# show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 192.168.31.22 1 FULL/BDR 00:00:36 192.168.1.2 FastEthernet0/0 192.168.31.33 1 FULL/DR 00:00:33 192.168.1.3 FastEthernet0/0 Asterix1# show ip ospf neighbor detail Neighbor 192.168.31.22, interface address 192.168.1.2 In the area 0 via interface FastEthernet0/0 Neighbor priority is 1, State is FULL, 8 state changes DR is 192.168.1.3 BDR is 192.168.1.2 Options is 0x52 LLS Options is 0x1 (LR) Dead timer due in 00:00:32 Neighbor is up for 00:06:26 Index 2/2, retransmission queue length 0, number of retransmission 1 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 1, maximum is 1 Last retransmission scan time is 0 msec, maximum is 0 msec Neighbor 192.168.31.33, interface address 192.168.1.3 In the area 0 via interface FastEthernet0/0 Neighbor priority is 1, State is FULL, 6 state changes DR is 192.168.1.3 BDR is 192.168.1.2 Options is 0x52 LLS Options is 0x1 (LR) Dead timer due in 00:00:30 Neighbor is up for 00:06:06 Index 1/1, retransmission queue length 0, number of retransmission 0 First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0) Last retransmission scan length is 0, maximum is 0 Last retransmission scan time is 0 msec, maximum is 0 msec
Most likely, the router with the highest router ID is the Designated Router (DR), the router with the second-highest router ID is the Backup Designated Router (BDR).
Because each interface on a given router is connected to a different network, some of the key OSPF information is interface specific. Issue the show ip ospf interface command for the FastEthernet interface on the router as follows:
Asterix1#show ip ospf interface FastEthernet0/0 is up, line protocol is up Internet Address 192.168.1.1/24, Area 0 Process ID 1, Router ID 192.168.31.11, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DROTHER, Priority 1 Designated Router (ID) 192.168.31.33, Interface address 192.168.1.3 Backup Designated router (ID) 192.168.31.22, Interface address 192.168.1.2 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:00 Supports Link-local Signaling (LLS) Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 0, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 2, Adjacent neighbor count is 2 Adjacent with neighbor 192.168.31.22 (Backup Designated Router) Adjacent with neighbor 192.168.31.33 (Designated Router) Suppress hello for 0 neighbor(s)
Ethernet networks are known to OSPF as broadcast networks. The default timer values are ten (10) second hello updates and 40 second dead intervals.

Step 5

It is decided to adjust OSPF timers so that the core routers will detect network failures in
less time. This will increase traffic, but this is less of a concern on the high speed core Ethernet segment than on a busy WAN link. It is also decided that the need for quick convergence at the core outweighs the extra traffic. Manually change the Hello and Dead intervals on Asterix1 as follows:Asterix1(config)#interface fastEthernet 0/0 Asterix1(config-if)#ip ospf hello-interval 5 Asterix1(config-if)#ip ospf dead-interval 20
These commands set the Hello update timer to five (5) seconds and the Dead interval to 20 seconds. Although the Cisco IOS does not require it, configure the Dead interval to four times the Hello interval. This ensures that routers experiencing temporary link problems can recover and are not declared dead unnecessarily, causing a ripple of updates and recalculations throughout the internetwork.
After the timers are changed on Asterix1, issue the show ip ospf neighbor command. Does Asterix1 still show that it has OSPF neighbors?
To find out what happened to Asterix1’s neighbors, use the IOS debug feature by entering the command debug ip ospf events as follows:Asterix1#debug ip ospf events OSPF events debugging is on Asterix1# *Mar 1 01:02:48.943: OSPF: Rcv hello from 192.168.31.22 area 0 from FastEtherne t0/0 192.168.1.2 *Mar 1 01:02:48.943: OSPF: Mismatched hello parameters from 192.168.1.2 *Mar 1 01:02:48.943: OSPF: Dead R 40 C 20, Hello R 10 C 5 Mask R 255.255.255.0 C 255.255.255.0 *Mar 1 01:02:49.231: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet0/0 fr om 192.168.1.1 Asterix1# *Mar 1 01:02:54.231: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet0/0 fr om 192.168.1.1 Asterix1# *Mar 1 01:02:56.335: OSPF: Rcv hello from 192.168.31.33 area 0 from FastEtherne t0/0 192.168.1.3 *Mar 1 01:02:56.335: OSPF: Mismatched hello parameters from 192.168.1.3 *Mar 1 01:02:56.339: OSPF: Dead R 40 C 20, Hello R 10 C 5 Mask R 255.255.255.0 C 255.255.255.0
The Hello and Dead intervals must be the same before routers within an area can form neighbor adjacencies.
Turn off debug using undebug all, or just u all.
The Hello and Dead intervals are declared in Hello packet headers. In order for OSPF routers to establish a relationship, their Hello and Dead intervals must match.
Configure the Asterix2 and Asterix3 Hello and Dead timers to match the timers on Asterix1. Before continuing, verify that these routers can now communicate by checking the OSPF neighbor table.

Step 6

Whether intentional, or by accident, no unauthorized routers exchanging updates within Area 0 are wanted. This is accomplished by adding encrypted authentication to each OSPF packet header. Select message digest (MD5) authentication. This mode of authentication sends a message digest, or hash, in place of the password. OSPF neighbors must be configured with the same message digest key number, encryption type, and password in order to authenticate using the hash.
To configure a message digest password for Asterix1 to use on its Ethernet interface, use the following commands:Asterix1(config)#interface fastethernet 0/0 Asterixe1(config-if)#ip ospf message-digest-key 1 md5 7 itsasecret Asterix1(config-if)#router ospf 1 Asterix1(config-router)#area 0 authentication message-digest
After entering these commands, wait 20 seconds, and then issue the show ip ospf neighbor command onAsterix1. Does Asterix1 still show that it has OSPF neighbors?
Use the debug ip ospf events command to determine why Asterix1 does not see its
neighbors:Asterix1#debug ip ospf events OSPF events debugging is on Asterix1# *Mar 1 01:17:09.227: OSPF: Rcv pkt from 192.168.1.2, FastEthernet0/0 : Mismatch Authentication type. Input packet specified type 0, we use type 2 *Mar 1 01:17:09.231: OSPF: Send with youngest Key 1 *Mar 1 01:17:09.231: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet0/0 fr om 192.168.1.1 Asterix1# *Mar 1 01:17:12.895: OSPF: Rcv pkt from 192.168.1.3, FastEthernet0/0 : Mismatch Authentication type. Input packet specified type 0, we use type 2
Again, it is seen that OSPF routers will not communicate unless certain configurations match. In this case, the routers are not communicating because the authentication fields in the OSPF packet header are different.
Correct this problem by configuring authentication on the other two routers. Remember that the same key number, encryption type, and password must be used on each router.
After the configurations are complete, verify that the routers can communicate by using the show ip ospf neighbors command.Asterix1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 192.168.31.22 1 FULL/BDR 00:00:17 192.168.1.2 FastEthernet0/0 192.168.31.33 1 FULL/DR 00:00:15 192.168.1.3 FastEthernet0/0

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Configuring OSPF

Configuring EIGRP Summarization

2009-06-08T12:45:00.003+07:00

Routers Used: 3640 w/ NM-4T and NM-1FE-TX modules

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab EIGRP will be configured and the operation will be tested over discontiguous subnets by disabling automatic route summarization. Discontiguous subnets are subnets that are out of order. Finally, EIGRP will be manually configured to use specific summary routes.

Scenario

The International Travel Agency uses VLSM to conserve IP addresses. All LANs are addressed using contiguous subnets, but the company would like to examine the effects of discontiguous subnets using EIGRP for future reference. The existence of multiple networks is simulated by loopback interfaces on the Arief router. The WAN links are addressed using 192.168.64.0 with a 30-bit mask.
Because this scheme creates discontiguous subnets, the default summarization behavior of EIGRP should result in incomplete routing tables. The problem should be resolved by disabling the default summarization in EIGRP while maintaining a route summary at the Arief router with manual route summarization.

Step 1

Build and configure the network according to the diagram. Add the loopback interfaces if the configuration files from the previous lab are used. This configuration requires the use of subnet 0. Therefore, check if this is enabled or enter the ip subnet-zero command, depending on which IOS version is used. Configure the Arief router with eight loopback interfaces using the IP addresses from the diagram. These interfaces simulate the existence of multiple networks behind the Arief router. Configure EIGRP as indicated for AS 100.
Use ping to verify that all serial interfaces can ping each other.
Note: Until the additional configurations are complete, not all networks will appear in the
routing table for each router.

Step 2

Use show ip route to check the routing table for Dion1 and Dion2.
Dion1 and Dion2 will install a summary route to 192.168.64.0/24 by way of Null0. EIGRP routers create these summary routes automatically. Because the local router has generated the summary, there is no next hop for the route. Therefore, the router maps this summary route to its null interface.
Dion1#show ip route (output omitted) Gateway of last resort is not set D 192.168.72.0/24 [90/2172416] via 192.168.64.2, 00:40:02, Serial0/0 D 172.16.0.0/16 [90/2297856] via 192.168.64.2, 00:28:57, Serial0/0 192.168.64.0/24 is variably subnetted, 3 subnets, 2 masks C 192.168.64.0/30 is directly connected, Serial0/0 D 192.168.64.0/24 is a summary, 00:40:03, Null0 D 192.168.64.4/30 [90/2681856] via 192.168.64.2, 00:40:03, Serial0/0 C 192.168.1.0/24 is directly connected, FastEthernet1/0 Dion2#show ip route (output omitted) Gateway of last resort is not set D 192.168.72.0/24 [90/2172416] via 192.168.64.6, 00:40:48, Serial0/0 D 172.16.0.0/16 [90/2297856] via 192.168.64.6, 00:29:43, Serial0/0 192.168.64.0/24 is variably subnetted, 3 subnets, 2 masks D 192.168.64.0/30 [90/2681856] via 192.168.64.6, 00:40:51, Serial0/0 D 192.168.64.0/24 is a summary, 00:40:49, Null0 C 192.168.64.4/30 is directly connected, Serial0/0 C 192.168.1.0/24 is directly connected, FastEthernet1/0
In order for all subnets to appear in the routing table, the default behavior of EIGRP that
automatically summarizes routes must be disabled.

Step 3

Disable the automatic summarization feature on EIGRP.
Dion1(config)#router eigrp 100 Dion1(config-router)#no auto-summary Dion2(config)#router eigrp 100 Dion2(config-router)#no auto-summary Arief(config)#router eigrp 100 Arief(config-router)#no auto-summary
After issuing these commands on all three routers, return to the Dion1 router and type the show ip route command.
Dion1#show ip route (output omitted) Gateway of last resort is not set D 192.168.72.0/24 [90/2172416] via 192.168.64.2, 00:56:40, Serial0/0 172.16.0.0/24 is subnetted, 8 subnets D 172.16.12.0 [90/2297856] via 192.168.64.2, 00:01:01, Serial0/0 D 172.16.13.0 [90/2297856] via 192.168.64.2, 00:01:01, Serial0/0 D 172.16.14.0 [90/2297856] via 192.168.64.2, 00:01:01, Serial0/0 D 172.16.15.0 [90/2297856] via 192.168.64.2, 00:01:01, Serial0/0 D 172.16.8.0 [90/2297856] via 192.168.64.2, 00:01:01, Serial0/0 D 172.16.9.0 [90/2297856] via 192.168.64.2, 00:01:01, Serial0/0 D 172.16.10.0 [90/2297856] via 192.168.64.2, 00:01:01, Serial0/0 D 172.16.11.0 [90/2297856] via 192.168.64.2, 00:01:01, Serial0/0 192.168.64.0/30 is subnetted, 2 subnets C 192.168.64.0 is directly connected, Serial0/0 D 192.168.64.4 [90/2172416] via 192.168.1.2, 00:01:52, FastEthernet1/0 C 192.168.1.0/24 is directly connected, FastEthernet1/0
Finally, to provide the most prescriptive routing updates, use the wildcard mask option for advertising networks in EIGRP. For a given classful network, all subnets need to be advertised with their exact subnet masks. This is completed through the wildcard mask. If just one subnet is advertised without the mask option then all other subnets will be advertised. To illustrate this, on Arief enter the following commands:
Arief(config)#router eigrp 100 Arief(config-router)#no network 172.16.0.0 Arief(config-router)#network 172.16.8.0 0.0.0.255
Now, enter show ip route on Dion1:
Dion1#show ip route (output omitted) Gateway of last resort is not set D 192.168.72.0/24 [90/2172416] via 192.168.64.2, 00:59:48, Serial0/0 172.16.0.0/24 is subnetted, 1 subnets D 172.16.8.0 [90/2297856] via 192.168.64.2, 00:00:09, Serial0/0 192.168.64.0/30 is subnetted, 2 subnets C 192.168.64.0 is directly connected, Serial0/0 D 192.168.64.4 [90/2172416] via 192.168.1.2, 00:04:59, FastEthernet1/0 C 192.168.1.0/24 is directly connected, FastEthernet1/0
The wildcard mask option in EIGRP allows prescriptive subnet advertisements, as long as each advertised subnet has the mask applied in the configuration.
Before proceeding to Step 4, remove the network 172.16.8.0 0.0.0.255 command on Arief and apply the network 172.16.0.0 command.

Step 4

Now that auto summarization is disabled, the International Travel Agency’s routers should build complete routing tables. Unfortunately, this means that the Arief router is advertising eight routes that should be summarized for efficiency. Use the manual summarization feature of EIGRP to summarize these addresses.
The Arief router should be advertising eight subnets:
• 172.16.8.0
• 172.16.9.0
• 172.16.10.0
• 172.16.11.0
• 172.16.12.0
• 172.16.13.0
• 172.16.14.0
• 172.16.15.0
The first 21 bits of these addresses are the same. Therefore, a summary route for all subnets can be created using a /21 prefix which is 255.255.248.0 in dotted-decimal notation.
Because the Arief router must advertise the summary route to the Dion1 and Dion2
routers, enter the following commands on the Arief router:
Arief(config)#interface s0/0 Arief(config-if)#ip summary-address eigrp 100 172.16.8.0 255.255.248.0 Arief(config-if)#interface s0/1 Aroef(config-if)#ip summary-address eigrp 100 172.16.8.0 255.255.248.0
These commands configure EIGRP to advertise summary routes for AS 100 through the serial 0/0 and 0/1 interfaces. Verify this configuration by issuing the show ip protocols command.
Arief#show ip protocols Routing Protocol is "eigrp 100" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Default networks flagged in outgoing updates Default networks accepted from incoming updates EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0 EIGRP maximum hopcount 100 EIGRP maximum metric variance 1 Redistributing: eigrp 100 EIGRP NSF-aware route hold timer is 240s Automatic network summarization is not in effect Address Summarization: 172.16.8.0/21 for Serial0/0, Serial0/1 Summarizing with metric 128256 Maximum path: 4 Routing for Networks: 172.16.0.0 192.168.64.0 192.168.72.0 Routing Information Sources: Gateway Distance Last Update (this router) 90 00:06:29 192.168.64.1 90 00:02:13 Gateway Distance Last Update 192.168.64.5 90 00:02:48 Distance: internal 90 external 170
After verifying manual address summarization on the Ariefn router, check the routing tables on Dion1 and Dion2.
From the Dion1 or Dion2 router, verify that 192.168.72.1 can be pinged. It should be possible to ping 172.16.15.1 from the Dion1 router.

Download

Configuring EIGRP Summarization

Configuring EIGRP Fault Tolerance

2009-06-04T15:32:00.004+07:00

Routers Used: 3640 w/ NM-4T and NM-1FE-TX modules

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab EIGRP will be configured over a full mesh topology and then tested to observe DUAL replace a successor with a feasible successor after a link failure.

Scenario

The International Travel Agency wants to run EIGRP on its core, branch, and regional routers. EIGRP is to be configured and tested for its ability to install alternate routes in the event of link failure.

Step 1

Build and configure the network according to the diagram, configuring EIGRP as indicated for AS 100. If using the configuration files from the previous lab, be sure to change IP addresses according to the diagram. Also, remove all loopback interfaces.
Set the bandwidth for each serial interface to reflect the diagram. Use the show interface
command to verify the configuration.
Use ping and show ip route to verify the configuration and test connectivity between all routers.

Step 2

Verify that EIGRP maintains all routes to destination networks in its topology table.
From the Dion2 router, issue the show ip eigrp topology all-links command:
Dion2#show ip eigrp topology all-links IP-EIGRP Topology Table for AS(100)/ID(192.168.64.5) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 192.168.72.0/24, 1 successors, FD is 2172416, serno 7 via 192.168.64.6 (2172416/28160), Serial0/0 via 192.168.1.1 (2174976/2172416), FastEthernet1/0 P 192.168.64.0/30, 1 successors, FD is 2681856, serno 6 via 192.168.64.6 (2681856/2169856), Serial0/0 P 192.168.64.0/24, 1 successors, FD is 2169856, serno 8 via Summary (2169856/0), Null0 via 192.168.1.1 (2172416/2169856), FastEthernet1/0 P 192.168.64.4/30, 1 successors, FD is 2169856, serno 4 via Connected, Serial0/0 P 192.168.1.0/24, 1 successors, FD is 28160, serno 1 via Connected, FastEthernet1/0
Note: The feasible distance (FD) for the route 192.168.72.0 is 2172416. The reported distance (RD) of the route to 192.168.72.0 by way of 192.168.1.1 is 2172416. The RD less than the FD. The of the route to 192.168.72.0 by way of 192.168.1.1 greater than the RD of the route to 192.168.72.0 by way of 192.168.64.6
The router topology table for Dion2 includes two paths to the 192.168.72.0 network. Use the show ip route to determine which path is installed in the Dion2 routing table.
Dion2#show ip route (output omitted) Gateway of last resort is not set D 192.168.72.0/24 [90/2172416] via 192.168.64.6, 00:36:41, Serial0/0 192.168.64.0/24 is variably subnetted, 3 subnets, 2 masks D 192.168.64.0/30 [90/2681856] via 192.168.64.6, 00:36:41, Serial0/0 D 192.168.64.0/24 is a summary, 00:36:38, Null0 C 192.168.64.4/30 is directly connected, Serial0/0 C 192.168.1.0/24 is directly connected, FastEthernet1/0
Both paths to 192.168.72.0 are listed in the topology table with their computed distance and reported distance in parentheses. The computed distance is listed first.

Step 3

To display debugging information about EIGRP feasible successor metrics (FSM) and to observe how EIGRP deals with the loss of a successor to a route, use the debug eigrp fsm command.
On the Dion2 router, issue the command debug eigrp fsm.
Next, shutdown or unplug the router serial connection to Dion2. This will cause the Dion2 router to lose its preferred route to 192.168.72.0 by way of 192.168.64.6.
Examine the debug eigrp fsm output for information regarding the route to 192.168.72.0, as shown in the following example:
Dion2#debug eigrp fsm EIGRP FSM Events/Actions debugging is on Dion2# *Mar 1 01:01:13.455: DUAL: dest(192.168.64.4/30) not active *Mar 1 01:01:13.455: DUAL: rcvquery: 192.168.64.4/30 via 192.168.1.1 metric 429 4967295/4294967295, RD is 2169856 *Mar 1 01:01:13.459: DUAL: send REPLY(r1/n1) about 192.168.64.4/30 to 192.168.1 .1 *Mar 1 01:01:13.859: DUAL: Removing dest 192.168.64.4/30, nexthop 192.168.1.1, infosource 192.168.1.1 Dion2# *Mar 1 01:01:24.819: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 192.168.64.6 (Serial0/0) is down: holding time expired *Mar 1 01:01:24.823: DUAL: linkdown: start - 192.168.64.6 via Serial0/0 *Mar 1 01:01:24.827: DUAL: Destination 192.168.72.0/24 *Mar 1 01:01:24.831: DUAL: Find FS for dest 192.168.72.0/24. FD is 2172416, RD is 2172416 *Mar 1 01:01:24.831: DUAL: 192.168.64.6 metric 4294967295/4294967295 *Mar 1 01:01:24.835: DUAL: 192.168.1.1 metric 2174976/2172416 not found Dmi n is 2174976 *Mar 1 01:01:24.839: DUAL: Peer total 1 stub 0 template 1 *Mar 1 01:01:24.843: DUAL: Dest 192.168.72.0/24 entering active state. *Mar 1 01:01:24.843: DUAL: Set reply-status table. Count is 1. *Mar 1 01:01:24.843: DUAL: Not doing split horizon *Mar 1 01:01:24.847: DUAL: Destination 192.168.64.0/30 *Mar 1 01:01:24.851: DUAL: Find FS for dest 192.168.64.0/30. FD is 2681856, RD is 2681856 *Mar 1 01:01:24.851: DUAL: 192.168.64.6 metric 4294967295/4294967295 not fo und Dmin is Dion2# 4294967295 *Mar 1 01:01:24.855: DUAL: Peer total 1 stub 0 template 1 *Mar 1 01:01:24.859: DUAL: Dest 192.168.64.0/30 entering active state. *Mar 1 01:01:24.859: DUAL: Set reply-status table. Count is 1. *Mar 1 01:01:24.863: DUAL: Not doing split horizon *Mar 1 01:01:24.863: DUAL: Destination 192.168.64.0/24 *Mar 1 01:01:24.867: DUAL: Destination 192.168.64.4/30 *Mar 1 01:01:24.871: DUAL: Destination 192.168.1.0/24 *Mar 1 01:01:24.879: DUAL: linkdown: finish *Mar 1 01:01:25.159: DUAL: rcvreply: 192.168.72.0/24 via 192.168.1.1 metric 217 4976/2172416 *Mar 1 01:01:25.163: DUAL: reply count is 1 *Mar 1 01:01:25.163: DUAL: Clearing handle 0, count now 0 *Mar 1 01:01:25.167: DUAL: Freeing reply status table *Mar 1 01:01:25.167: DUAL: Find FS for dest 192.168.72.0/24. FD is 4294967295, RD is 4294967295 found *Mar 1 01:01:25.175: DUAL: Removing dest 192.168.72.0/24, nexthop 192.168.64.6, infosource 192.168.64.6 *Mar 1 01:01:25.179: DUAL: RT installed 192.168.72.0 Dion2#/24 via 192.168.1.1 *Mar 1 01:01:25.179: DUAL: Send update about 192.168.72.0/24. Reason: metric c hg *Mar 1 01:01:25.183: DUAL: Send update about 192.168.72.0/24. Reason: new if *Mar 1 01:01:25.187: DUAL: dest(192.168.64.0/30) active *Mar 1 01:01:25.187: DUAL: rcvreply: 192.168.64.0/30 via 192.168.1.1 metric 429 4967295/4294967295 *Mar 1 01:01:25.191: DUAL: reply count is 1 *Mar 1 01:01:25.191: DUAL: Clearing handle 0, count now 0 *Mar 1 01:01:25.195: DUAL: Freeing reply status table *Mar 1 01:01:25.195: DUAL: Find FS for dest 192.168.64.0/30. FD is 4294967295, RD is 4294967295 found *Mar 1 01:01:25.203: DUAL: Removing dest 192.168.64.0/30, nexthop 192.168.64.6, infosource 192.168.64.6 *Mar 1 01:01:25.207: DUAL: Removing dest 192.168.64.0/30, nexthop 192.168.1.1, infosource 192.168.1.1 *Mar 1 01:01:25.211: DUAL: No routes. Flushing dest 192.168.64.0/30 Dion2# *Mar 1 01:01:42.187: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to down *Mar 1 01:01:42.207: DUAL: rcvupdate: 192.168.64.4/30 via Connected metric 4294 967295/4294967295 *Mar 1 01:01:42.211: DUAL: Find FS for dest 192.168.64.4/30. FD is 2169856, RD is 2169856 *Mar 1 01:01:42.211: DUAL: 0.0.0.0 metric 4294967295/4294967295 not found D min is 4294967295 *Mar 1 01:01:42.215: DUAL: Peer total 1 stub 0 template 1 *Mar 1 01:01:42.219: DUAL: Dest 192.168.64.4/30 entering active state. *Mar 1 01:01:42.219: DUAL: Set reply-status table. Count is 1. *Mar 1 01:01:42.223: DUAL: Not doing split horizon *Mar 1 01:01:42.235: DUAL: rcvupdate: 192.168.64.0/24 via Summary metric 429496 7295/4294967295 Dion2# *Mar 1 01:01:42.239: DUAL: Find FS for dest 192.168.64.0/24. FD is 2169856, RD is 2169856 *Mar 1 01:01:42.243: DUAL: 0.0.0.0 metric 4294967295/4294967295 *Mar 1 01:01:42.243: DUAL: 192.168.1.1 metric 2172416/2169856 not found Dmi n is 2172416 *Mar 1 01:01:42.247: DUAL: Peer total 1 stub 0 template 1 *Mar 1 01:01:42.251: DUAL: Dest 192.168.64.0/24 entering active state. *Mar 1 01:01:42.251: DUAL: Set reply-status table. Count is 1. *Mar 1 01:01:42.255: DUAL: Not doing split horizon *Mar 1 01:01:42.727: DUAL: dest(192.168.64.4/30) active *Mar 1 01:01:42.727: DUAL: rcvreply: 192.168.64.4/30 via 192.168.1.1 metric 429 4967295/4294967295 *Mar 1 01:01:42.731: DUAL: reply count is 1 *Mar 1 01:01:42.731: DUAL: Clearing handle 0, count now 0 *Mar 1 01:01:42.735: DUAL: Freeing reply status table *Mar 1 01:01:42.739: DUAL: Find FS for dest 192.168.64.4/30. FD is 4294967295, RD is 4294967295 found *Mar 1 01:01:42.743: DUAL: Removing dest 192.168.64.4/30, nexthop 0.0.0 Dion2#.0, infosource 0.0.0.0 *Mar 1 01:01:42.747: DUAL: Removing dest 192.168.64.4/30, nexthop 192.168.1.1, infosource 192.168.1.1 *Mar 1 01:01:42.747: DUAL: No routes. Flushing dest 192.168.64.4/30 *Mar 1 01:01:42.751: DUAL: rcvreply: 192.168.64.0/24 via 192.168.1.1 metric 217 2416/2169856 *Mar 1 01:01:42.755: DUAL: reply count is 1 *Mar 1 01:01:42.755: DUAL: Clearing handle 0, count now 0 *Mar 1 01:01:42.759: DUAL: Freeing reply status table *Mar 1 01:01:42.759: DUAL: Find FS for dest 192.168.64.0/24. FD is 4294967295, RD is 4294967295 found *Mar 1 01:01:42.767: DUAL: Removing dest 192.168.64.0/24, nexthop 0.0.0.0, info source 0.0.0.0 *Mar 1 01:01:42.771: DUAL: RT installed 192.168.64.0/24 via 192.168.1.1 *Mar 1 01:01:42.771: DUAL: Send update about 192.168.64.0/24. Reason: metric c hg *Mar 1 01:01:42.775: DUAL: Send update about 192.168.64.0/24. Reason: new if *Mar 1 01:01:42.787: DUAL: Find FS for dest 192.168.64.0/24. FD is 2172416, RD is 2172416 *Mar 1 01:01: Dion2#42.791: DUAL: 192.168.1.1 metric 2172416/2169856 found Dmin is 2172416 *Mar 1 01:01:42.791: DUAL: RT installed 192.168.64.0/24 via 192.168.1.1
The output shows DUAL attempting to locate a feasible successor
(FS) for 192.168.72.0. In this case, DUAL failed to find a feasible successor, and the router entered the active state. After querying its EIGRP neighbors, Dion2 locates and installs a route to 192.168.72.0/24 by way of 192.168.1.1.

Step 4

Verify that the new route has been installed by using the show ip route command.Dion2#show ip route (output omitted) Gateway of last resort is not set D 192.168.72.0/24 [90/2174976] via 192.168.1.1, 00:02:02, FastEthernet1/0 D 192.168.64.0/24 [90/2172416] via 192.168.1.1, 00:01:44, FastEthernet1/0 C 192.168.1.0/24 is directly connected, FastEthernet1/0
Bring the Dion2 router serial interface back up. 192.168.64.6 will be restored as the preferred route to the 192.168.72.0 network.

Download

Configuring EIGRP Fault Tolerance

Configuring EIGRP

2009-06-03T15:49:00.004+07:00

Routers Used: 3640 w/ NM-4T modules

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab EIGRP will be configured on three Cisco routers within the International Travel Agency WAN and the basic behaviors of the protocol will be observed.

Scenario

The International Travel Agency is implementing EIGRP. EIGRP must be configured at all three locations before the Dion1 headquarters can connect to the Dion2 headquarters.

Step 1

Build and configure the network according to the diagram, but do not configure EIGRP yet.
Use ping to test connectivity between serial interfaces. Dion1 and Dion2 will not be able to ping each other until EIGRP is enabled.

Step 2

Configure EIGRP for AS 100 on all routers as the following shows:
Dion1(config)#router eigrp 100 Dion1(config-router)#network 192.168.100.0 Dion1(config-router)#network 172.16.0.0 Arief(config)#router eigrp 100 Arief(config-router)#network 172.16.0.0 Dion2(config)#router eigrp 100 Dion2(config-router)#network 192.168.200.0 Dion2(config-router)#network 172.16.0.0

Step 3

After enabling EIGRP on each of the three routers, verify the operation using the show ip route command on the Arief router. The Arief router should have routes to all networks.
Arief#show ip route
(output omitted) Gateway of last resort is not set 172.16.0.0/30 is subnetted, 2 subnets C 172.16.224.4 is directly connected, Serial0/1 C 172.16.224.0 is directly connected, Serial0/0 D 192.168.200.0/24 [90/2297856] via 172.16.224.5, 00:15:29, Serial0/1 D 192.168.100.0/24 [90/2297856] via 172.16.224.1, 00:19:55, Serial0/0
The Arief router received EIGRP routes that are internal to the EIGRP domain, 192.168.100.0 and 192.168.200.0. Internally learned EIGRP routes are denoted by a D.

Step 4

Now that EIGRP is configured, use show commands to view EIGRP neighbors and topology tables on the Arief router.
Arief#show ip eigrp neighbors IP-EIGRP neighbors for process 100 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 1 172.16.224.5 Se0/1 14 00:22:00 195 1170 0 7 0 172.16.224.1 Se0/0 14 00:23:02 238 1428 0 6
To view the topology table, issue the show ip eigrp topology all-links command.
Arief#show ip eigrp topology all-links IP-EIGRP Topology Table for AS(100)/ID(172.16.224.6) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 192.168.100.0/24, 1 successors, FD is 2297856, serno 3 via 172.16.224.1 (2297856/128256), Serial0/0 P 172.16.224.4/30, 1 successors, FD is 2169856, serno 2 via Connected, Serial0/1 P 172.16.224.0/30, 1 successors, FD is 2169856, serno 1 via Connected, Serial0/0 P 192.168.200.0/24, 1 successors, FD is 2297856, serno 8 via 172.16.224.5 (2297856/128256), Serial0/1
To view more specific information about a topology table entry, use an IP address with the show ip eigrp topology command:
Arief#show ip eigrp topology 192.168.200.0 IP-EIGRP (AS 100): Topology entry for 192.168.200.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 2297856 Routing Descriptor Blocks: 172.16.224.5 (Serial0/1), from 172.16.224.5, Send flag is 0x0 Composite metric is (2297856/128256), Route is Internal Vector metric: Minimum bandwidth is 1544 Kbit Total delay is 25000 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 1
Finally, use show commands to view key EIGRP statistics. On the Arief router, issue the show ip eigrp traffic command to see the EIGRP packet types. Then enter the show ip eigrp interfaces command.
Arief#show ip eigrp traffic IP-EIGRP Traffic Statistics for AS 100 Hellos sent/received: 688/674 Updates sent/received: 12/7 Queries sent/received: 2/1 Replies sent/received: 2/2 Acks sent/received: 3/9 SIA-Queries sent/received: 0/0 SIA-Replies sent/received: 0/0 Hello Process ID: 136 PDM Process ID: 135 IP Socket queue: 0/2000/3/0 (current/max/highest/drops) Eigrp input queue: 0/2000/3/0 (current/max/highest/drops) Arief#show ip eigrp interfaces IP-EIGRP interfaces for process 100 Xmit Queue Mean Pacing Time Multicast Pending Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes Se0/0 1 0/0 238 0/15 1027 0 Se0/1 1 0/0 195 0/15 823 0

Download

Configuring EIGRP

Online CCNA Lab

2009-06-02T15:10:00.005+07:00

The Cisco CCNA network associate certification validates the ability to install, configure, operate, and troubleshoot medium-size routed and switched networks, including implementation and verification of connections to remote sites in a WAN. This new curriculum includes basic mitigation of security threats, introduction to wireless networking concepts and terminology, and performance-based skills. This new curriculum also includes (but is not limited to) the use of these protocols: IP, Enhanced Interior Gateway Routing Protocol (EIGRP), Serial Line Interface Protocol Frame Relay, Routing Information Protocol Version 2 (RIPv2),VLANs, Ethernet, access control lists (ACLs).

(Source: http://lab177.vn2k.net)

Connecting to Cisco Router console port using Linux

2009-06-02T10:32:00.008+07:00

I tried to connect my Ubuntu laptop to Cisco Router console port. I did successfully.

What you will need:

A roll-over cable (Cisco Console Cable). These are usually RJ-45 on the router side and serial on the PC side.
If your laptop doesn’t have a serial port (like mine) you can get a 9-pin D-sub serial to USB cable. I got the BAFO USB Serial to DB9. I bought it in Ambassador Mall Kuningan Jakarta last night.

Get Connected:

Connect all the cables: USB -> Serial -> Crossover –> Console Port
Download and Install Putty.
root@dion-laptop:~# apt-get install putty
Make sure that the USB to serial cable is recognized.
root@dion-laptop:~# dmesg | grep tty [ 0.004000] console [tty0] enabled [ 1.923508] tty ptyx4: hash matches [ 131.637904] usb 3-2: pl2303 converter now attached to ttyUSB0 [ 173.768300] type=1503 audit(1243914954.561:5): operation="inode_permission" requested_mask="w::" denied_mask="w::" fsuid=0 name="/dev/ttyUSB0" pid=6127 profile="/usr/sbin/cupsd"
Note:
COM1 is /dev/ttyS0 in Linux.
USB to Serial is /dev/ttyUSB0 in Linux.
Run putty.
Good luck!

Using your Real PC in GNS3

2009-05-29T11:06:00.004+07:00

One of the interesting things about GNS3 and Dynamips is that you can connect your topology to the real world. For some of your CCNA and CCNP studies you may need to run an actual Web browser or Cisco’s Security Device Manager (SDM) among others. Just connect your topology to your real PC. You could even connect to virtual machines running on your computer inside VMware or Virtual PC. I’ve even set up two copies of Windows XP Professional running inside VMware virtual machines. Then I ran Cisco soft IP Phones that could talk to themselves. You could connect your virtual network to a real network as well. Connecting a virtual topology running within GNS3 and Dynamips to real devices is very exciting, but again, your throughput is going to be limited compared to using real equipment for the entire topology. It only makes sense to use GNS3 and Dynamips in a lab environment and for learning purposes. Any other usage is highly discouraged!

Connecting your topology to your real PC is very similar to the process used with the Virtual PC Simulator above. Drag a computer (defined as cloud) into your workspace. Right-click the computer and choose Configure. Click on C0 under Clouds, but choose the NIO Ethernet tab. Administrator rights are required. For Windows users, click on the box directly beneath Generic Ethernet NIO, and choose the network adapter you wish to use.

Click the Add button and OK. You will need to configure the IP settings for your computer’s adapter, and then use the Add a link toolbar button to create your connection.

You may create an MS Loopback adapter to connect to. In Windows, use the Add Hardware wizard in Control Panel. Choose “Yes, I have already connected the hardware". On the next screen, choose Add a new hardware device at the end of the list and click Next. Choose to “Install the hardware manually…” and click Next. Choose Network Adapters in the list and click Next. Choose Microsoft as the manufacturer and then Microsoft Loopback Adapter as the network adapter. Finish the wizard. Then right-click My Network Places and choose Properties. You may wish to rename the new Local Area Connection as MS Loopback Adapter. Also, assign the proper IP settings to the adapter in order to connect to your topology.

Using a Router that acts Like a PC

2009-05-29T10:49:00.004+07:00

You may also simply add another router to your topology and configure it to act like a PC. This method would use more memory and processor cycles than the previous method, so I would only recommend this method as a secondary choice.
Just add a router and enter the following commands:


Router(config)# no ip routing (Turns off IP routing function )
Router(config)# interface fa0/0 (Switches to FastEthernet interface)
Router(config-if)# ip address address subnet_mask (Assigns IP address and subnet mask to interface )
Router(config-if)# no shutdown (Turns interface on )
Router(config-if)# exit (Returns to global configuration mode )
Router(config)# ip default-gateway (gateway_address Configures the default gateway )
Router(config)# ip http server (Optional – starts http server process Connect the router (acting as a PC) to the rest of your topology.)

How to Add Virtual PC to your GNS3 Topology

2009-05-29T09:49:00.004+07:00

The Virtual PC Simulator is a program that runs within Windows or Linux. It has limited functionality, but most important, it allows pings and traceroutes. These are the most common testing commands used during CCNA or CCNP training and are often the only commands needed. Using VPCS you will save memory and CPU cycles. If you do not need more functionality in a workstation within your topology, I highly recommend VPCS. The Virtual PC Simulator is a free product available at the following.

Web site: http://wiki.freecode.com.cn/doku.php?id=wiki:vpcs

How to install in windows?

Download the software here and extract to your folder. You will find file cygwin1.dll in the extracted folder.
Go to C:\Program Files\GNS3\Dynamips, search and rename the file cygwin1.dll into cygwin1.dll.old and copy the file cygwin1.dll from your vpcs folder to this folder.
Open command prompt, enter the vpcs folder and type vpcs.exe. It is best to open the Virtual PC Simulator before starting GNS3.
Welcome to Virtual PC Simulator for dynamips, v0.16c Dedicated to Daling. Build time: Mar 12 2009 11:32:18 All rights reserved. NOTICE: MAY NOT use this software for commercial purposes unless you get an appropriate commercial license for it. Please contact me at mirnshi@gmail.com or http://mirnshi.cublog.cn if you have any questions. Press '?' to get help. Executing the startup file DDD
If it doesn't work, you may need to install cygwyn released by cygwin.com.
The VPCS allow you to simulate up to 9 PCs. Just type a number to switch to another PC. Use the Show command to view a PC’s IP or MAC address. To assign an IP address, subnet mask, and default gateway to a PC, follow this format at the prompt:
VPCS 9 >1 VPCS 1 >show NAME IP/CIDR GATEWAY MAC LPORT RPORT PC1 0.0.0.0/0 0.0.0.0 00:50:79:66:68:00 20000 30000 PC2 0.0.0.0/0 0.0.0.0 00:50:79:66:68:01 20001 30001 PC3 192.168.2.1/24 0.0.0.0 00:50:79:66:68:02 20002 30002 2001:2::1/64 PC4 192.168.2.2/24 0.0.0.0 00:50:79:66:68:03 20003 30003 2001:2::2/64 PC5 192.168.3.2/24 192.168.3.1 00:50:79:66:68:04 20004 30004 2001:3::2/64 PC6 0.0.0.0/0 0.0.0.0 00:50:79:66:68:05 20005 30005 PC7 0.0.0.0/0 0.0.0.0 00:50:79:66:68:06 20006 30006 PC8 192.168.8.2/24 192.168.8.1 00:50:79:66:68:07 20007 30007 2001:8::2/64 PC9 192.168.9.2/24 192.168.9.1 00:50:79:66:68:08 20008 30008 2001:9::2/64 VPCS 1 >ip 192.168.1.2/24 192.168.1.1 PC1 : 192.168.1.2 255.255.255.0 gateway 192.168.1.1 VPCS 1 >
To integrate VPCS into GNS3, we will first make use of the Symbol Library. Choose Symbol Manager on the Edit menu after opening GNS3. Click the computer symbol under Available symbols, then click right arrow button between the windows. This will move the symbol into the Customized nodes column. In the Name box, type computer. Use the drop-down arrow to change the type to Cloud, if necessary. Click the Apply button. Then click OK. In the GNS3 Nodes Types column, you should now see a computer icon.
Drag the computer into the workspace. Right-click the computer, and choose Configure. Click on C0 under Clouds. Click the NIO UDP tab. Type in the following values under Settings:
Local port: 30000 Remote host: localhost Remote port: 20000
These settings correspond to VPCS 1. Click the Add button and then OK.
Connect your router or switch to vpcs's nio_udp port.
Return to router’s console window to configure its Ethernet or FastEthernet port.
Test the connection end-to-end with the ping and tracert command.

Routing between RIP v1 and RIP v2

2009-05-28T10:52:00.004+07:00

Routers Used: 3640 w/ NM-4T and NM-1FE-TX modules

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab, configure RIP v1 and RIP v2 routing protocols. RIP v2 will be configured to accept RIP v1 updates.

Scenario

RIP v1 is presently running between Jakarta, Tegal, and Surabaya. New routers that support RIP v2 and variable-length subnet mask (VLSM) have been installed at the Tegal and Surabaya headquarters. However, an upgrade of the Jakarta router, which presently does not support RIP v2 will be installed at a later time. RIP v2 will have to be configured between Tegal and Surabaya. Surabaya will then need to be configured to receive RIP v1 updates so the Jakarta router will be able to communicate with Tegal.

Step 1

Build the network according to the diagram and configure all routers with RIP v1. Test connectivity between the routers and troubleshoot as necessary. A ping should be successful from one end of the network to the other.

Step 2

Verify that RIP v1 is running. There are several commands that could be used to verify RIP v1 is enabled and running. Two of the commands are shown below:
Jakarta#sh ip protocols Routing Protocol is "rip" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Sending updates every 30 seconds, next due in 24 seconds Invalid after 180 seconds, hold down 180, flushed after 240 Redistributing: rip Default version control: send version 1, receive any version Interface Send Recv Triggered RIP Key-chain Serial0/0 1 1 2 FastEthernet1/0 1 1 2 Automatic network summarization is in effect Maximum path: 4 Routing for Networks: 192.168.1.0 192.168.224.0 Routing Information Sources: Gateway Distance Last Update 192.168.224.1 120 00:00:03 Distance: (default is 120)
The debug router rip command can be used to check the type of updates the router is receiving and sending.
Jakarta# *Mar 1 00:28:13.111: RIP: received v1 update from 192.168.224.1 on Serial0/0 *Mar 1 00:28:13.115: 192.168.3.0 in 1 hops *Mar 1 00:28:13.119: 192.168.240.0 in 1 hops *Mar 1 00:28:13.119: 192.168.252.0 in 1 hops Jakarta# *Mar 1 00:28:17.211: RIP: sending v1 update to 255.255.255.255 via FastEthernet 1/0 (192.168.1.3) *Mar 1 00:28:17.215: RIP: build update entries *Mar 1 00:28:17.215: network 192.168.3.0 metric 1 *Mar 1 00:28:17.219: network 192.168.224.0 metric 1 *Mar 1 00:28:17.219: network 192.168.240.0 metric 1 *Mar 1 00:28:17.223: network 192.168.252.0 metric 1
Notice that all RIP v1 updates are sent using broadcast addresses through all the interfaces. The advertisements are also classful. That is, no mask information is carried in a RIP v1 update. RIP v1 does not support classless interdomain routing (CIDR) and VLSM.
Turn debug off if it is enabled and check that a route to 192.168.1.0 exists in the routing tables of the Tegal and Surabaya routers.

Step 3

The next step is to configure RIP v2 on the Tegal and Surabaya routers.
Tegal(config)#router rip Tegal(config-router)#version 2 Surabaya(config)#router rip Surabaya(config-router)#version 2
Issue a show running-config command on either Tegal or Surabaya and notice that RIP version 1 was replaced by RIP version 2. Issue the clear ip route * command to flush the
routing table.
Check the routing table of the Tegal and Surabaya routers. Is there still a route to 192.168.1.0 on either router?
By default, RIP v1 will accept RIP v2 updates. However, RIP v2 will not accept RIP v1 updates. Therefore, RIP v2 must be configured to accept RIP v1 updates.
When debug ip rip is issued on the Jakarta and Tegal routers, it is possible to view RIP v1 accepting RIP v2 updates and RIP v2 ignoring RIP v1 updates. A sample output is shown below.
Jakarta# *Mar 1 00:40:21.275: RIP: sending v1 update to 255.255.255.255 via FastEthernet 1/0 (192.168.1.3) *Mar 1 00:40:21.279: RIP: build update entries *Mar 1 00:40:21.279: network 192.168.3.0 metric 1 *Mar 1 00:40:21.283: network 192.168.224.0 metric 1 *Mar 1 00:40:21.283: network 192.168.240.0 metric 1 *Mar 1 00:40:21.287: network 192.168.252.0 metric 1 *Mar 1 00:40:22.239: RIP: received v2 update from 192.168.224.1 on Serial0/0 *Mar 1 00:40:22.243: 192.168.3.0/24 via 0.0.0.0 in 1 hops *Mar 1 00:40:22.247: 192.168.240.0/24 via 0.0.0.0 in 1 hops *Mar 1 00:40:22.247: 192.168.252.0/24 via 0.0.0.0 in 1 hops Tegal# *Mar 1 00:40:04.551: RIP: ignored v1 packet from 192.168.224.2 (illegal version ) *Mar 1 00:40:04.719: RIP: sending v2 update to 224.0.0.9 via FastEthernet1/0 (1 92.168.3.1) *Mar 1 00:40:04.723: RIP: build update entries *Mar 1 00:40:04.723: 192.168.1.0/24 via 0.0.0.0, metric 1, tag 0 *Mar 1 00:40:04.727: 192.168.224.0/24 via 0.0.0.0, metric 1, tag 0 *Mar 1 00:40:04.727: 192.168.240.0/24 via 0.0.0.0, metric 1, tag 0 *Mar 1 00:40:04.731: 192.168.252.0/24 via 0.0.0.0, metric 1, tag 0

Step 4

Configure RIP v2 to accept RIP v1 updates.
Tegal(config-if)#interface serial 0/0 Tegal(config-if)#ip rip receive version 1
Issue the clear ip route * command to flush the routing table. Check the Tegal and
Surabaya routing tables again. Is there a route for network 192.168.1.0?
Enable the debug ip rip command on Tegal to see RIP v2 now accepting RIP v1 updates. A sample output is shown below.
Tegal# *Mar 1 00:52:00.659: RIP: received v1 update from 192.168.224.2 on Serial0/0 *Mar 1 00:52:00.663: 192.168.1.0 in 1 hops Tegal# *Mar 1 00:52:08.675: RIP: sending v2 update to 224.0.0.9 via Serial0/1 (192.168 .240.1) *Mar 1 00:52:08.679: RIP: build update entries *Mar 1 00:52:08.679: 192.168.1.0/24 via 0.0.0.0, metric 1, tag 0 *Mar 1 00:52:08.683: 192.168.3.0/24 via 0.0.0.0, metric 1, tag 0 *Mar 1 00:52:08.683: 192.168.224.0/24 via 0.0.0.0, metric 1, tag 0 Tegal# *Mar 1 00:52:10.631: RIP: sending v2 update to 224.0.0.9 via Serial0/0 (192.168 .224.1) *Mar 1 00:52:10.631: RIP: build update entries *Mar 1 00:52:10.631: 192.168.3.0/24 via 0.0.0.0, metric 1, tag 0 *Mar 1 00:52:10.631: 192.168.240.0/24 via 0.0.0.0, metric 1, tag 0 *Mar 1 00:52:10.631: 192.168.252.0/24 via 0.0.0.0, metric 1, tag 0

Download

Routing between RIP v1 and RIP v2

Subnet Calculator

2009-05-27T13:41:00.005+07:00

Don't be confused to calculate subnet of your IP Address. Please download and try this tool from Boson. Also useful to check wildcard Mask. It displays Host IP address, mask bits, the class of address, range of addresses for that class and the binary representation of that address.

Configuring IGRP

2009-05-27T12:18:00.004+07:00

Routers Used: 2621 w/ CISCO2600-MB-2FE and WIC-2T modules

IOS: c2600-i-mz.121-5.T9

Objective

In this lab, configure IGRP for unequal cost load balancing and tune IGRP timers to improve performance.

Scenario

International Travel Agency (ITA) has asked for IGRP to be implemented in its WAN.

Step 1

Build and configure the network according to the diagram. If the configuration files are used from the previous lab, remove all routing protocols.
Note: PC1 and PC2 are not required to complete this lab, but they might be used in
testing or as Telnet clients. If used, the PC1 gateway may be either Dion1 router or
the Dion2 router.
On all three routers, configure IGRP for Autonomous System 24, and enable updates on all active interfaces with the network command.
Arief(config)#router igrp 24 Arief(config)#network 192.168.1.0 Arief(config)#network 192.168.2.0 Arief(config)#network 192.168.3.0 Dion1(config)#router igrp 24 Dion1(config)#network 192.168.1.0 Dion1(config)#network 10.0.0.0 Dion2(config)#router igrp 24 Dion2(config)#network 192.168.2.0 Dion2(config)#network 10.0.0.0
The IGRP metric includes bandwidth in its calculation. Manually configure the bandwidth of serial interfaces in order for metrics to be accurate. Use the following commands to configure the correct bandwidth settings for each serial interface:
Dion(config)#interface serial 0/0 Dion1(config-if)#bandwidth 256 Arief(config)#interface serial 0/0 Arief(config-if)#bandwidth 256 Arief(config-if)#interface serial 0/1 Arief(config-if)#bandwidth 384 Dion2(config-if)#interface serial 0/0 Dion2(config-if)#bandwidth 384
Use the output from the show interface command to verify the correct bandwidth settings. Use ping and show ip route to verify full connectivity within the network.

Step 2

On Arief, configure unequal cost load balancing using the variance 5 command
Note: A default value of 1 is used for equal cost load balancing. The following are sample
commands for Arief:
Arief(config)#router igrp 24 Arief(config-router)#variance 5
Use the show ip route command to verify that the routers are installing two unequal cost routes to the same destination:
Arief#show ip route (output omitted) I 10.0.0.0/8 [100/41072] via 192.168.1.2, 00:00:22, Serial0/0 [100/28051] via 192.168.2.2, 00:00:03, Serial0/1 C 192.168.1.0/24 is directly connected, Serial0/0 C 192.168.2.0/24 is directly connected, Serial0/1 C 192.168.3.0/24 is directly connected, FastEthernet0/0

Step 3

On any router, issue the show ip protocols command and check the IGRP invalid, holddown, and flush timers for IGRP.
Note: A route does not become invalid until after 270 seconds and is not flushed from the
table until after more than 10 minutes or 630 seconds. Also, the maximum hop count is set
at 100 by default.
In small networks, it is advised that the timers for IGRP be adjusted to speed up the convergence process.
Fast IGRP is a specific set of timer settings that result in improved convergence. To configure Fast IGRP, change the IGRP timers as follows:
• 15 seconds between updates
• 45 seconds for route expiration
• 0 seconds for holddown
• 60 seconds for flushing the route from the table
As part of this configuration disable the holddown timers completely. This is done so that after the route for a given network has been removed, a new route for that destination network will be accepted immediately. Finally, reduce the IGRP maximum hop count to a number appropriate to the ITA network.
Dion1(config)#router igrp 24 Dion1(config-router)#timers basic 15 45 0 60 Dion1(config-router)#no metric holddown Dion1(config-router)#metric maximum-hops 10
Verify the settings with the show ip protocols command.

Step 4

In this step, test the IGRP timer settings by simulating a link failure.
On Dion1, enable debug so that any changes to the routing table will be reported to the console:
Dion1#debug ip routing
With the connection to Dion1 open, log into Arief. Do this on a separate workstation if
necessary. On Arief, shut down the Fast Ethernet interface. This will cause the removal of 192.168.3.0 /24 from the Arief routing table.
Arief(config)#interface fastethernet 0/0 Arief(config-if)#shutdown
Use the show ip route command to verify that Arief no longer possesses a valid route to
192.168.3.0 /24.
Return to Dion1 and issue the show ip route command
Note: The route to 192.168.3.0 is still in the Dion1 table, but it is flagged as possibly
down.
Dion1#sh ip route (output omitted) C 10.0.0.0/8 is directly connected, FastEthernet0/0 C 192.168.1.0/24 is directly connected, Serial0/0 I 192.168.2.0/24 [100/28051] via 10.0.0.2, 00:00:08, FastEthernet0/0 I 192.168.3.0/24 is possibly down, routing via 10.0.0.2, FastEthernet0/0

Download

Configuring IGRP

Migrating from RIP to EIGRP

2009-05-27T10:35:00.005+07:00

Routers Used: 3640 w/ NM-4T and NM-1FE-TX modules

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab, configure RIP v2 and then EIGRP so that their metric calculations can be compared.

Scenario

International Travel Agency (ITA) currently uses RIP v2 as its interior gateway protocol. Migrate its network to EIGRP.

Step 1

Build and configure the network according to the diagram.
Note: PC1 and PC2 are not required to complete this lab, but they might be used in
testing or as Telnet clients. If used, the PC1 gateway may be either Dion1 router or the Dion2 router.
On all three routers, configure RIP v2 and enable updates on all active interfaces with the network command:
Dion1(config)#router rip Dion1(config-router)#version 2 Dion1(config-router)#network 192.168.1.0 Dion1(config-router)#network 10.0.0.0 Dion2(config)#router rip Dion2(config-router)#version 2 Dion2(config-router)#network 192.168.2.0 Dion2(config-router)#network 10.0.0.0 Arief(config)#router rip Arief(config-router)#version 2 Arief(config-router)#network 192.168.1.0 Arief(config-router)#network 192.168.2.0 Arief(config-router)#network 192.168.3.0
Use ping and show ip route to verify full connectivity within the network.

Step 2

While migrating to EIGRP, leave RIP running on all the routers to avoid a loss of connectivity. On Dion1 and Dion2, configure EIGRP for Autonomous System 24. Do not configure Arief for EIGRP yet.
Dion1(config)#router eigrp 24 Dion1(config-router)#network 192.168.1.0 Dion1(config-router)#network 10.0.0.0 Dion2(config)#router eigrp 24 Dion2(config-router)#network 192.168.2.0 Dion2(config-router)#network 10.0.0.0

Step 3

From the Arief console, issue the show ip route command. The EIGRP has not be configured on this router yet. Therefore, a route has been established to the 10.0.0.0 /8 network through the RIP.
Enable debug so that changes to the routing table will be reported to the console.
Arief#debug ip routing
Now enable EIGRP on Arief.
Arief(config)#router eigrp 24 Arief(config-router)#network 192.168.1.0 Arief(config-router)#network 192.168.2.0 Arief(config-router)#network 192.168.3.0
Issue the show ip route command again from Arief. There should now be an EIGRP route to network 10.0.0.0 /8.

Step 4

To see more with the debug ip routing command, force the routing table to rebuild with this command:
Arief#clear ip route *

Step 5

To complete the migration from RIP to EIGRP, disable RIP on all three routers using the command no router rip.
Next, enter the command show ip route:
Arief#show ip route Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route Gateway of last resort is not set D 10.0.0.0/8 [90/2172416] via 192.168.2.2, 00:50:01, Serial0/1 [90/2172416] via 192.168.1.2, 00:50:01, Serial0/0 C 192.168.1.0/24 is directly connected, Serial0/0 C 192.168.2.0/24 is directly connected, Serial0/1 C 192.168.3.0/24 is directly connected, FastEthernet1/0
Turn off debug before exiting the Arief router.
Arief#no debug all

Download

Migrating from RIP to EIGRP

Network Address Translation – Port Address Translation and Port Forwarding

2009-05-26T15:54:00.008+07:00

Routers Used: 2621 w/ CISCO2600-MB-2FE and WIC-2T modules

IOS: c2600-i-mz.121-5.T9

Objective

In this lab, Port Address Translation (PAT) and port forwarding are configured.

Scenario

The International Travel Agency is planning to launch an informational Web site on a local Webserver for the general public. However, the one Class C address that has been allocated will not be sufficient for the users and devices the company has on this network. Therefore, a network is configured that will allow all internal company users access to the Internet and all Internet users access to the company’s informational Web server through static NAT and PAT. Internal user addresses must be translated to one legal global address and all Internet Users must access the informational Web server through the one legal global address as well.

Step 1

Build and configure the network according to the diagram. If you are using the configuration files from the previous lab, remove the NAT pool (public) and the static and dynamic NAT configurations. Use a Cisco router as WebServer if another Web server is not available.
Use ping to test connectivity between the NAT and ISP routers, between the Internal User and the NAT router, and between the Internet User and ISP.
Also check that WebServer server is accessible by connecting to it from the Internal User
workstation with a browser using the WebServer IP address, 192.168.1.5.

Step 2

Since no routing protocol will be enabled, configure a default route to the Internet from the NAT router.
NAT(config)#ip route 0.0.0.0 0.0.0.0 200.200.100.2

Step 3

Create a standard Access Control List that would enable all Internal Users access to the Internet.
NAT(config)#access-list 1 permit 192.168.1.0 0.0.0.255

Step 4

Because a single inside global address, 200,200.100.1, will be used to represent multiple inside local addresses, 192.168.1.x, simultaneously, apply the access list and configure NAT overload on the serial 0/0 interface of the NAT router. In general, NAT can used to overload a pool of public addresses, when a single external address is overloaded. This is referred to as port address translation (PAT).
NAT(config)#ip nat inside source list 1 interface s0/0 overload
This configuration allows Internal Users to access the Internet, but blocks external users from accessing internal hosts.

Step 5

Now specify the inside and outside NAT interfaces.
NAT(config)#interface fastethernet 0/0 NAT(config-if)#ip nat inside NAT(config-if)#interface serial 0/0 NAT(config-if)#ip nat outside

Enter the command ping 200.200.50.2 from the Internal User workstation. Then, on the NAT router, enter the commands show ip nat translations, show ip nat statistics, and show ip nat translations verbose. Sample output follows.
NAT#sh ip nat translations Pro Inside global Inside local Outside local Outside global icmp 200.200.100.1:27057 192.168.1.2:27057 200.200.50.2:27057 200.200.50.2:27057 icmp 200.200.100.1:26033 192.168.1.5:26033 200.200.50.2:26033 200.200.50.2:26033 icmp 200.200.100.1:27313 192.168.1.2:27313 200.200.50.2:27313 200.200.50.2:27313 icmp 200.200.100.1:26289 192.168.1.5:26289 200.200.50.2:26289 200.200.50.2:26289 NAT#show ip nat statistics Total active translations: 4 (0 static, 4 dynamic; 4 extended) Outside interfaces: Serial0/0 Inside interfaces: FastEthernet0/0 Hits: 85 Misses: 18 Expired translations: 10 Dynamic mappings: -- Inside Source access-list 1 interface Serial0/0 refcount 4 NAT#show ip nat translations verbose Pro Inside global Inside local Outside local Outside global icmp 200.200.100.1:27057 192.168.1.2:27057 200.200.50.2:27057 200.200.50.2:2705 create 00:00:45, use 00:00:45, left 00:00:14, flags: extended, use_count: 0 icmp 200.200.100.1:26033 192.168.1.5:26033 200.200.50.2:26033 200.200.50.2:2603 create 00:00:49, use 00:00:49, left 00:00:10, flags: extended, use_count: 0 icmp 200.200.100.1:27313 192.168.1.2:27313 200.200.50.2:27313 200.200.50.2:2731 create 00:00:45, use 00:00:44, left 00:00:15, flags: extended, use_count: 0 icmp 200.200.100.1:26289 192.168.1.5:26289 200.200.50.2:26289 200.200.50.2:2628 create 00:00:49, use 00:00:48, left 00:00:11, flags: extended, use_count: 0

Step 6

Internet users need access to the informational Web server through 200.200.100.1 through port 80. Configure PAT so that Internet users are directed to the informational Web server, 192.168.1.5, when they connect to the IP address 200.200.100.1 through a web browser.
NAT(config)#ip nat inside source static tcp 192.168.1.5 80 200.200.100.1 80 extendable
The extendable keyword at the end of this static NAT command causes the router to reuse the global address of an active translation and save enough information to distinguish it from another translation entry. This command has the effect of translating external attempts to connect to port 80/IP address 200.200.100.1 to internal attempts to connect to port 80/IP address 192.168.1.5. The process of performing NAT translations based on the value of the incoming port number of an IP packet is called port forwarding.

Step 7

Successful configuration of port forwarding is indicated by being able to reach the informational Web server from the Internet User workstation with a Web browser using the inside global address of 200.200.100.1.

Download

Network Address Translation – Port Address Translation and Port Forwarding

Network Address Translation – Static NAT and Dynamic NAT

2009-05-26T10:45:00.007+07:00

Routers Used: 2621 w/ CISCO2600-MB-2FE and WIC-2T modules

IOS: c2600-i-mz.121-5.T9

Objective

In this lab, static Network Address Translation (NAT) and dynamic NAT are configured.

Scenario

The International Travel Agency needs approximately 100 private IP addresses translated in a oneto-one fashion with a pool of public IP addresses. To do this, ITA will use NAT translation with a portion of its class C address space allocated by ISP.

Step 1

Build and configure the network according to the diagram.
Use ping to test connectivity between the NAT and ISP routers, between the workstations and the default gateway, and between SERVER and ISP.

Step 2

Since no routing protocol will be enabled, configure a default route to the Internet on the NAT router:
NAT(config)#ip route 0.0.0.0 0.0.0.0 200.200.100.2
ISP needs to be able to reach hosts on the 192.168.0/24 network. But these hosts will have their IP addresses translated to public IP addresses in the 200.200.100.128/25 network, so a static route to the 200.200.100.128/25 network is required:
ISP(config)#ip route 200.200.100.128 255.255.255.128 200.200.100.1

Step 3

Create a standard Access Control List that defines all Internal Users:
NAT(config)#access-list 1 permit 192.168.1.0 0.0.0.255

Step 4

In this step, configure private and public address spaces to be used for NAT and configure the translation:
The public address space 200.200.100.128/25 will be used as a pool to provide NAT translation for the private IP addresses. To statically map the Internal User with IP address 192.168.1.2 pictured in the diagram, enter the following command:
NAT(config)#ip nat inside source static 192.168.1.2 200.200.100.252
This static mapping has the advantage of allowing “external” users to always access the host 192.168.1.2 by way of the fixed IP address 200.200.100.252 (in addition to letting the 192.168.1.2 Internal User access the Internet). On the down side, this external accessibility is also viewed as a security vulnerability. To allow the other hosts on the internal (private) network to reach the Internet, translations will need to be made for those hosts as well. A list of static translations could be made one by one, but a simpler alternative is to configure a pool of addresses and let the router make oneto-one dynamic NAT translations for these hosts. For example, to map the non-statically mapped hosts in the 192.168.1.0/24 network to public IP addresses in the range 200.200.100.129 to 200.200.100.250, proceed as follows:
NAT(config)#ip nat pool public 200.200.100.129 200.200.100.250 netmask 255.255.255.128 NAT(config)#ip nat inside source list 1 pool public
This provides a dynamic one-to-one NAT translation between public IP addresses in the “public” pool and private IP addresses specified by access list 1. The Internal Users IP addresses are configured independently of the NAT translation. Dynamic NAT translations are made for any internal hosts for which no static translation has been defined. The configuration above reserves IP addresses 200.200.100.251 to 200.200.100.254 for use in further static NAT mappings. Static translations are often used with an internal server to enable external access to it by way of a fixed external IP.

Note: If there are more than 128 active hosts on the private network, static NAT translation and/or dynamic one-to-one NAT translations will prevent more than 128 hosts from accessing the Internet. For these additional hosts to get on the Internet, “NAT overloading” must be configured.

Step 5

Now, designate the inside NAT interface and the outside NAT interface. In more complex topologies, it is possible to have more than one inside NAT interface.
NAT(config)#interface fastethernet 0/0 NAT(config-if)#ip nat inside NAT(config-if)#interface serial 0/0 NAT(config-if)#ip nat outside
There are several show commands that can be used to see if NAT is working: show ip nat translations, show ip nat statistics, and show ip nat translations verbose.
From the two Internal User workstations, ping SERVER (200.200.50.2). Then check that SERVER is accessible by connecting from an Internal User workstation using a browser with the SERVER IP address, 200.200.50.2. Issue the three NAT show commands listed above on the NAT router. Sample outputs are shown below.
NAT#show ip nat translations Pro Inside global Inside local Outside local Outside global --- 200.200.100.129 192.168.1.5 --- --- --- 200.200.100.130 192.168.1.2 --- --- NAT#show ip nat statistics Total active translations: 2 (0 static, 2 dynamic; 0 extended) Outside interfaces: Serial0/0 Inside interfaces: FastEthernet0/0 Hits: 39 Misses: 5 Expired translations: 0 Dynamic mappings: -- Inside Source access-list 1 pool public refcount 2 pool public: netmask 255.255.255.128 start 200.200.100.129 end 200.200.100.250 type generic, total addresses 122, allocated 2 (1%), misses 0 NAT#show ip nat translations verbose Pro Inside global Inside local Outside local Outside global --- 200.200.100.129 192.168.1.5 --- --- create 00:02:25, use 00:02:17, left 23:57:42, flags: none, use_count: 0 --- 200.200.100.130 192.168.1.2 --- --- create 00:02:06, use 00:01:58, left 23:58:01, flags: none, use_count: 0
The command clear ip nat translation * can be used to clear all dynamic NAT translations.

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Network Address Translation – Static NAT and Dynamic NAT

Using DHCP and IP Helper Addresses

2009-05-14T16:35:00.006+07:00

Routers Used: 3640 w/ NM-4T and NM-1FE-TX modules

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab, configure a Cisco router to act as a DHCP server for clients on two separate subnets. The IP helper address feature will also be used to forward DHCP requests from a remote subnet.

Scenario

Clients on the 192.168.3.0/24 network and the 10.0.0.0/8 network require the services of DHCP for automatic IP configuration. Configure Aristo serve both subnets by creating two separate address pools. Finally, configure the FastEthernet interface of the Arief router to forward UDP broadcasts, including DHCP requests, to Aris.

Step 1

Build and configure the network according to the diagram. Connect HostA and HostB as shown, but configure these clients to obtain their IP addresses automatically. Because these hosts rely on DHCP, they cannot be tested using ping until Step 5.
Configure RIP v2 on Aris and Arief. Be sure to enable updates on all active interfaces with the network command:
Aris(config)#router rip Aris(config)#version 2 Aris(config-router)#network 192.168.1.0 Aris(config-router)#network 10.0.0.0 Aris(config)#router rip Arief(config-router)#version 2 Arief(config-router)#network 192.168.1.0 Arief(config-router)#network 192.168.3.0
Use ping and show ip route to verify the work and test connectivity between Aris and Arief.

Step 2

Configure Aris to act as a DHCP server for clients on the 10.0.0.0/8 network.
First, verify that Aris can use DHCP services and that it is enabled:
Aris(config)#service dhcp
Next, configure the DHCP address pool for the 10.0.0.0 network. Name the pool 10-net:
Aris(config)#ip dhcp pool 10-net Aris(dhcp-config)#network 10.0.0.0 255.0.0.0

Step 3

International Travel Agency uses the first ten addresses in this address range to statically address servers and routers. From global configuration mode, exclude addresses from the DHCP pool so that the server does not attempt to assign them to clients. Configure Aris to dynamically assign addresses from the 10-net pool, starting with 10.0.0.11:
Aris(config)#ip dhcp excluded-address 10.0.0.1 10.0.0.10

Step 4

Return to DHCP configuration mode and assign the IP options of the default gateway address, DNS server address, WINS server address, and domain name:
Aris(dhcp-config)#default-router 10.0.0.1 Aris(dhcp-config)#dns-server 10.0.0.3 Aris(dhcp-config)#netbios-name-server 10.0.0.4 Aris(dhcp-config)#domain-name dion.co.id

Step 5

The DHCP server is now ready to be tested. Release and renew the IP configuration for HostA.
HostA should be dynamically assigned the first available address in the pool, which is 10.0.0.11. Check the configuration of HostA with dhcp to verify that it received the proper IP address, subnet mask, default gateway. But DNS server address and WINS server address is not shown because this Lab uses virtual pc. Check the configuration of HostA with dhcp and show
VPCS 4 >dhcp DDORA, IP 10.0.0.12/8 GW 10.0.0.1 VPCS 4 >show NAME IP/CIDR GATEWAY MAC LPORT RPORT PC1 192.168.1.66/27 192.168.1.65 00:50:79:66:68:00 20000 30000 PC2 192.168.1.35/27 192.168.1.34 00:50:79:66:68:01 20001 30001 PC3 192.168.3.2/24 192.168.3.1 00:50:79:66:68:02 20002 30002 2001:2::1/64 PC4 10.0.0.12/8 10.0.0.1 00:50:79:66:68:03 20003 30003 2001:2::2/64

Step 6

Because HostB also requires dynamic IP configuration, create a second DHCP pool with address and gateway options appropriate to its network, 192.168.3.0/24:
Aris(config)#ip dhcp pool 192.168.3-net Aris(dhcp-config)#network 192.168.3.0 255.255.255.0 Aris(dhcp-config)#default-router 192.168.3.1 Aris(dhcp-config)#dns-server 10.0.0.3 Aris(dhcp-config)#netbios-name-server 10.0.0.4 Aris(dhcp-config)#domain-name dion.co.id

Step7

The configuration of the DHCP server is now complete. However, HostB uses a UDP broadcast to find an IP address, and Arief is not configured to forward broadcasts. In order for DHCP to work, configure the FastEthernet interface of the Arief router to forward UDP broadcasts to Aris:
Arief(config)#interface fastethernet 1/0 Arief(config-if)#ip helper-address 192.168.1.2

Step 8

Verify virtual PC, using dhcp or show, that HostB received the correct IP configuration.
VPCS 3 >dhcp DORA, IP 192.168.3.2/24 GW 192.168.3.1 VPCS 3 >show NAME IP/CIDR GATEWAY MAC LPORT RPORT PC1 192.168.1.66/27 192.168.1.65 00:50:79:66:68:00 20000 30000 PC2 192.168.1.35/27 192.168.1.34 00:50:79:66:68:01 20001 30001 PC3 192.168.3.2/24 192.168.3.1 00:50:79:66:68:02 20002 30002 2001:2::1/64
An ip dhcp excluded-address command was not issued. The DHCP server did not
assign HostB 192.168.3.1. Why not?
Issue show ip dhcp ? and note the choices.
Aris#show ip dhcp ? binding DHCP address bindings conflict DHCP address conflicts database DHCP database agents import Show Imported Parameters relay Miscellaneous DHCP relay information server Miscellaneous DHCP server information
Try the conflict and binding options.
Aris#sh ip dhcp binding Bindings from all pools not associated with VRF: IP address Client-ID/ Lease expiration Type Hardware address/ User name 10.0.0.12 0050.7966.6803.ff Mar 02 2002 12:19 AM Automatic 192.168.3.2 0050.7966.6802.ff Mar 02 2002 12:02 AM Automatic Aris#sh ip dhcp conflict IP address Detection method Detection time VRF 192.168.3.1 Ping Mar 01 2002 12:02 AM
How did Aris know to assign HostB an address from the 3-net pool and not the 10-net pool?
Aris#show ip dhcp server statistics Memory usage 26690 Address pools 2 Database agents 0 Automatic bindings 2 Manual bindings 0 Expired bindings 0 Malformed messages 0 Secure arp entries 0 Message Received BOOTREQUEST 0 DHCPDISCOVER 6 DHCPREQUEST 3 DHCPDECLINE 0 DHCPRELEASE 0 DHCPINFORM 0 Message Sent BOOTREPLY 0 DHCPOFFER 5 DHCPACK 3 DHCPNAK 0

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Using DHCP and IP Helper Addresses

How to find Cisco IOS with Google

2009-05-14T14:58:00.003+07:00

I used Google as my primary search Engine. I will show you some trick to search Cisco IOS out of the Internet by using this powerful search engine.

Type this keyword in Google.com:
intitle:index.of ios parent directory bin
Or just clickt here.

You can also search for unique Cisco series.
7200 search with:
intitle:index.of c7200*.bin -site:cisco.com
Or just click here
3640 search with:
intitle:index.of c3640*.bin -site:cisco.com
Or just click here
2600 search with:
intitle:index.of c2600*.bin -site:cisco.com
Or just click here
PIX search with:
intitle:index.of cisco pix*.bin -site:cisco.com
Or just click here

Configuring VLSM and IP Unnumbered

2009-05-14T13:32:00.004+07:00

Routers Used: 3640 w/ NM-4T and NM-4E modules

IOS: c3640-jk9s-mz.124-16a

Objective

In this lab, the student will configure VLSM and test its functionality with two different routing protocols, RIP v1 and RIP v2. Finally, the student will use IP unnumbered in place of VLSM to further conserve addresses.

Scenario

When International Travel Agency was much smaller, it wanted to configure its network using a single Class C address, 192.168.1.0, as shown in the following table. The routers need to be configured with the appropriate addresses. The company requires that at least 25 host addresses be available on each LAN, but it also demands that the maximum number of addresses be conserved for future growth.
To support 25 hosts on each subnet, a minimum of five (5) bits is needed in the host portion of the address. Five (5) bits will yield 30 possible host addresses (25 = 32 - 2). If five (5) bits must be used for hosts, the other three (3) bits in the last octet can be added to the default 24-bit Class C mask. Therefore, a 27-bit mask can be used to create the following subnets:

Step 1

Build and configure the network according to the diagram. This configuration requires the use of subnet 0, so the ip subnet-zero command may be required. This will depend on which IOS version is being used.
Note: PC1 and PC2 are not required to complete this lab.
On all three routers, configure RIP v1 and enable updates on all active interfaces with this network command:
Dion1(config)#router rip Dion1(config-router)#network 192.168.1.0
Use ping to verify that each router can ping its directly connected neighbor.

Note: Some remote networks might be unreachable. Proceed to Step 2 anyway.

Step 2

Issue the show ip route command on Vista, as shown in the following example:
Vista#show ip route (output ommited) Gateway of last resort is not set 192.168.1.0/24 is variably subnetted, 3 subnets, 2 masks C 192.168.1.64/27 is directly connected, Ethernet1/0 C 192.168.1.0/30 is directly connected, Serial0/0 C 192.168.1.4/30 is directly connected, Serial0/1
The 192.168.1.32 /27 subnet is clearly absent from the routing table of Vista.
The other routers also have incomplete tables. Why is this so?
Because RIP v1 with VLSM is being used, routing has broken down on the network. Remember that VLSM is not supported by classful routing protocols such as RIP v1 and IGRP. These protocols do not send subnet masks in their routing updates. In order for routing to work, RIP v2 must be configured, which does support VLSM.

Step 3

At each of three router consoles, enable RIP v2 updates and turn off automatic route summarization, as shown in the following example:
Dion1(config)#router rip Dion1(config)#network 192.168.1.0 (in case RIP was removed) Dion1(config-router)#version 2 Dion1(config-router)#no auto-summary
Configuring no auto-summary disables the automatic summarization of subnet routes into
network-level routes. This allows subnet information to be sent across classful network boundaries.
Note that RIP v1 does not support this feature because it requires VLSM support.
When all three routers are running RIP v2, return to Vista and examine its routing table. It should now be complete, shown as follows:
Vista#show ip route (output omitted) Gateway of last resort is not set 192.168.1.0/24 is variably subnetted, 4 subnets, 2 masks C 192.168.1.64/27 is directly connected, Ethernet1/0 R 192.168.1.32/27 [120/1] via 192.168.1.6, 00:00:12, Serial0/1 [120/1] via 192.168.1.2, 00:00:13, Serial0/0 C 192.168.1.0/30 is directly connected, Serial0/0 C 192.168.1.4/30 is directly connected, Serial0/1
Notice that Vista has received equal cost routes to 192.168.1.32 /27 from both Dion1 and Dion2.

Step 4

Although VLSM has reduced address waste by creating very small subnets for point-to-point links, the IP unnumbered feature can make it unnecessary to address these links altogether. Further maximize address use by configuring IP unnumbered on every serial interface in the WAN. To configure IP unnumbered, use the following commands:
Dion1(config)#interface serial 0/0 Dion1(config-if)#ip unnumbered ethernet 1/0 Vista(config)#interface serial 0/0 Vista(config-if)#ip unnumbered ethernet 1/0 Vista(config-if)#interface serial 0/1 Vista(config-if)#ip unnumbered ethernet 1/0 Dion2(config)#interface serial 0/0 Dion2(config-if)#ip unnumbered ethernet 1/0
After the IP unnumbered configuration is complete, each serial interface borrows the address of the local LAN interface. Check the routing table on the Vista router again:
Vista#show ip route (output omitted) Gateway of last resort is not set 192.168.1.0/27 is subnetted, 2 subnets C 192.168.1.64 is directly connected, Ethernet1/0 R 192.168.1.32 [120/1] via 192.168.1.33, 00:00:08, Serial0/0 [120/1] via 192.168.1.34, 00:00:00, Serial0/11
If IP unnumbered were configured on the point-to-point serial links, only the LANs would require addresses in this topology. Because each LAN uses the same 27-bit mask, VLSM would not be required in this case. This would make classful routing protocols, such as RIP v1 and IGRP, viable options.

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Configuring VLSM and IP Unnumbered