Lab Objective:
The focus of this lab is to understand EIGRP implementation and configuration in Cisco IOS routers. Additional technologies tested include path control, summarization and optimization.
Lab Topology:
The lab network topology is illustrated below:
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IMPORTANT NOTE If you are using the www.howtonetwork.net racks, please bring up the LAN interfaces connected to the routers by issuing the no shutdown command on the connected switches. If you are using a home lab with no interface fastethernet 0/0 Alternately, you can simply connect the interfaces to a hub or switch if you have one available in your own lab. |
Task 1
Configure hostnames and IP addressing on all routers as illustrated in the network topology.
Task 2
Configure EIGRP for AS 100 as illustrated in the topology. Ensure that the 150.1.1.0/24 subnet is advertised as an external EIGRP route with a route tag of 111 from R1 and 444 from R4. Verify your configuration using the appropriate commands.
Ensure that neither R1 nor R4 has a duplicate entry for this subnet in the EIGRP topology table. You are NOT allowed to use IP ACLs or IP prefix lists to implement this solution. Verify your configuration using the appropriate commands.
Task 3
Configure the 10.5.0.0/24, 10.5.1.0/24, 10.5.2.0/24, and 10.5.3.0/24 secondary subnets on the LAN segment between R1 and R4. Use the .1 address for R1 and the .4 address for R4. These should be advertised via EIGRP as internal EIGRP routes.
Task 4
Configure EIGRP on routers R1 and R4 to advertise a single summary route for the 10.5.0.0/24, 10.5.1.0/24, 10.5.2.0/24, and 10.5.3.0/24 secondary subnets. Verify this on R2 and R3.
Task 5
Without removing the summary configuration on routers R1 and R4, adding any static routes, or using PBR; configure your network so that R2 and R3 prefer the path via R1 to reach the 10.5.0.0/24 subnet; and the path via R4 to reach the 10.5.3.0/24 subnet. As a hint, use an EIGRP feature to complete this task. Verify your configuration using the appropriate commands.
Task 6
Management has advised that within the next year, the EIGRP network will scale to at least 200 routers and switches. These routers will be comprised of Cisco 2900 series routers running IOS Software 15.3. The switches will be Cisco Catalyst 6500 series switches, ranging from Catalyst 6504 through Catalyst 6513 switches. These will all be Multilayer switches. The future network will run both IPv4 and IPv6Configure the current EIGRP implementation to support the future EIGRP network. Verify your configuration using the appropriate commands.
Lab Validation
Task 1
| Router(config)#hostname R1 R1(config)#interface fastethernet 0/0 R1(config-if)#no shutdown R1(config-if)#ip address 150.1.1.1 255.255.255.0 R1(config-if)#exit R1(config)#interface serial 0/0 R1(config-if)#no shutdown R1(config-if)#ip address 10.0.0.1 255.255.255.252 R1(config-if)#clock rate 2000000 R1(config-if)#exit |
| Router(config)#hostname R2 R2(config)#interface serial 0/0 R2(config-if)#no shutdown R2(config-if)#ip address 10.0.0.2 255.255.255.252 R2(config-if)#exit R2(config)#interface serial 0/0 R2(config-if)#no shutdown R2(config-if)#ip address 10.0.0.9 255.255.255.252 R2(config-if)#exit |
| Router(config)#hostname R3 R3(config)#interface serial 1/1 R3(config-if)#no shutdown R3(config-if)#ip address 10.0.0.10 255.255.255.252 R3(config-if)#clock rate 128000 R3(config-if)#exit R3(config)#interface serial 1/2 R3(config-if)#no shutdown R3(config-if)#ip address 10.0.0.13 255.255.255.252 R3(config-if)#clock rate 128000 R3(config-if)#exit |
| Router(config)#hostname R4 R4(config)#interface fastethernet 0/0 R4(config-if)#no shutdown R4(config-if)#ip address 150.4.4.4 255.255.255.0 R4(config-if)#exit R4(config)#interface serial 0/0 R4(config-if)#no shutdown R4(config-if)#ip address 10.0.0.14 255.255.255.252 R4(config-if)#exit |
Task 2
| R1(config)#route-map CONNECTED permit 10 R1(config-route-map)#match interface fastethernet 0/0 R1(config-route-map)#set tag 111 R1(config-route-map)#exit R1(config)#router eigrp 100 R1(config-router)#network 10.0.0.1 0.0.0.0 R1(config-router)#no auto-summary R1(config-router)#redistribute connected route-map CONNECTED R1(config-router)#exit |
| R2(config)#router eigrp 100 R2(config-router)#no auto-summary R2(config-router)#network 10.0.0.2 0.0.0.0 R2(config-router)#network 10.0.0.9 0.0.0.0 R2(config-router)#exit |
| R3(config)#router eigrp 100 R3(config-router)#no auto-summary R3(config-router)#network 10.0.0.10 0.0.0.0 R3(config-router)#network 10.0.0.13 0.0.0.0 R3(config-router)#exit |
| R4(config)#route-map CONNECTED permit 10 R4(config-route-map)#match interface fastethernet 0/0 R4(config-route-map)#set tag 444 R4(config-route-map)#exit R4(config)#route-map CONNECTED deny 20 R4(config-route-map)#exit R4(config)#router eigrp 100 R4(config-router)#no auto-summary R4(config-router)#network 10.0.0.14 0.0.0.0 R4(config-router)#no auto-summary R4(config-router)#redistribute connected route-map CONNECTED R4(config-router)#exit |
Verify your base EIGRP configuration by verifying EIGRP neighbor relationships:
| R1#show ip eigrp neighbors IP-EIGRP neighbors for process 100 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 0 10.0.0.2 Se0/0 12 00:03:53 6 200 0 10 |
| R2#show ip eigrp neighbors IP-EIGRP neighbors for process 100 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 1 10.0.0.10 Se0/1 14 00:03:18 10 200 0 10 0 10.0.0.1 Se0/0 11 00:03:59 3 200 0 3 |
| R3#show ip eigrp neighbors IP-EIGRP neighbors for process 100 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 1 10.0.0.14 Se1/2 13 00:01:27 12 1140 0 5 0 10.0.0.9 Se1/1 10 00:03:21 10 1140 0 9 |
| R4#show ip eigrp neighbors IP-EIGRP neighbors for process 100 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 0 10.0.0.13 Se0/0 11 00:01:31 12 200 0 9 |
After configuring redistribution, the EIGRP topology tables on the routers show the following:
| R1#show ip eigrp topology 150.1.1.0 255.255.255.0 IP-EIGRP (AS 100): Topology entry for 150.1.1.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 28160 Routing Descriptor Blocks: 0.0.0.0, from Rconnected, Send flag is 0x0 Composite metric is (28160/0), Route is External Vector metric: Minimum bandwidth is 100000 Kbit Total delay is 100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 0 External data: Originating router is 150.1.1.1 (this system) AS number of route is 0 External protocol is Connected, external metric is 0 Administrator tag is 111 (0x0000006F) |
| R4#show ip eigrp topology 150.1.1.0 255.255.255.0 IP-EIGRP (AS 100): Topology entry for 150.1.1.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 28160 Routing Descriptor Blocks: 0.0.0.0, from Rconnected, Send flag is 0x0 Composite metric is (28160/0), Route is External Vector metric: Minimum bandwidth is 100000 Kbit Total delay is 100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 0 External data: Originating router is 150.1.1.4 (this system) AS number of route is 0 External protocol is Connected, external metric is 0 Administrator tag is 444 (0x000001BC) 10.0.0.13 (Serial0/0), from 10.0.0.13, Send flag is 0x0 Composite metric is (21538560/21026560), Route is External Vector metric: Minimum bandwidth is 128 Kbit Total delay is 60100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 3 External data: Originating router is 150.1.1.1 AS number of route is 0 External protocol is Connected, external metric is 0 Administrator tag is 111 (0x0000006F) |
In the output above, we can see that R4 has a duplicate entry for the 150.1.1.0/24 subnet. This is the entry received from R1 with an administrative route tag of 111. To prevent either router from receiving or accepting the other routers’ advertisement, a distribute list used with a route map is required. The route map should perform filtering based on route tags:
| R1(config)#route-map NOT-TAG-444 deny 10 R1(config-route-map)#match tag 444 R1(config-route-map)#exit R1(config)#route-map NO-TAG-444 permit 20 R1(config-route-map)#exit R1(config)#router eigrp 100 R1(config-router)#distribute-list route-map NO-TAG-444 in R1(config-router)#exit |
| R4(config)#route-map NO-TAG-111 deny 10 R4(config-route-map)#match tag 111 R4(config-route-map)#exit R4(config)#route-map NO-TAG-11 permit 20 R4(config-route-map)#exit R4(config)#router eigrp 100 R4(config-router)#distribute-list route-map NO-TAG-111 in R4(config-router)#exit |
Following this configuration, the topology tables on R1 and R4 show the following:
| R1#show ip eigrp topology 150.1.1.0 255.255.255.0 IP-EIGRP (AS 100): Topology entry for 150.1.1.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 28160 Routing Descriptor Blocks: 0.0.0.0, from Rconnected, Send flag is 0x0 Composite metric is (28160/0), Route is External Vector metric: Minimum bandwidth is 100000 Kbit Total delay is 100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 0 External data: Originating router is 150.1.1.1 (this system) AS number of route is 0 External protocol is Connected, external metric is 0 Administrator tag is 111 (0x0000006F) |
| R4#show ip eigrp topology 150.1.1.0 255.255.255.0 IP-EIGRP (AS 100): Topology entry for 150.1.1.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 28160 Routing Descriptor Blocks: 0.0.0.0, from Rconnected, Send flag is 0x0 Composite metric is (28160/0), Route is External Vector metric: Minimum bandwidth is 100000 Kbit Total delay is 100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 0 External data: Originating router is 150.1.1.4 (this system) AS number of route is 0 External protocol is Connected, external metric is 0 Administrator tag is 444 (0x000001BC) |
Task 3
| R1(config)#interface fastethernet 0/0 R1(config-if)#ip address 10.5.0.1 255.255.255.0 secondary R1(config-if)#ip address 10.5.1.1 255.255.255.0 secondary R1(config-if)#ip address 10.5.2.1 255.255.255.0 secondary R1(config-if)#ip address 10.5.3.1 255.255.255.0 secondary R1(config-if)#exit R1(config)#router eigrp 100 R1(config-router)#network 10.5.0.0 0.0.3.255 R1(config-router)#exit |
| R4(config)#interface fastethernet 0/0 R4(config-if)#ip address 10.5.0.4 255.255.255.0 secondary R4(config-if)#ip address 10.5.1.4 255.255.255.0 secondary R4(config-if)#ip address 10.5.2.4 255.255.255.0 secondary R4(config-if)#ip address 10.5.3.4 255.255.255.0 secondary R4(config-if)#exit R4(config)#router eigrp 100 R4(config-router)#network 10.5.0.0 0.0.3.255 R4(config-router)#exit |
Verify that the prefixes are advertised to R2 and R3 using the show ip route command:
| R2#show ip route eigrp 10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks D 10.0.0.12/30 [90/2684416] via 10.0.0.1, 00:02:30, Serial0/0 D 10.5.3.0/24 [90/2172416] via 10.0.0.1, 00:02:32, Serial0/0 D 10.5.2.0/24 [90/2172416] via 10.0.0.1, 00:02:32, Serial0/0 D 10.5.1.0/24 [90/2172416] via 10.0.0.1, 00:02:32, Serial0/0 D 10.5.0.0/24 [90/2172416] via 10.0.0.1, 00:02:32, Serial0/0 150.1.0.0/24 is subnetted, 1 subnets D EX 150.1.1.0 [170/2172416] via 10.0.0.1, 00:21:51, Serial0/0 |
| R3#show ip route eigrp 10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks D 10.0.0.0/30 [90/21024000] via 10.0.0.9, 00:24:19, Serial1/1 D 10.5.3.0/24 [90/20514560] via 10.0.0.14, 00:02:51, Serial1/2 D 10.5.2.0/24 [90/20514560] via 10.0.0.14, 00:02:51, Serial1/2 D 10.5.1.0/24 [90/20514560] via 10.0.0.14, 00:02:51, Serial1/2 D 10.5.0.0/24 [90/20514560] via 10.0.0.14, 00:02:51, Serial1/2 150.1.0.0/24 is subnetted, 1 subnets D EX 150.1.1.0 [170/20514560] via 10.0.0.14, 00:22:10, Serial1/2 |
Task 4
| R1(config)#interface serial 0/0 R1(config-if)#ip summary-address eigrp 100 10.5.0.0 255.255.252.0 R1(config-if)#exit |
| R4(config)#interface serial 0/0 R4(config-if)#ip summary-address eigrp 100 10.5.0.0 255.255.252.0 R4(config-if)#exit |
Verify that the summaries are advertised to R2 and R3 using the show ip route command:
| R2#show ip route eigrp 10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks D 10.0.0.12/30 [90/2684416] via 10.0.0.1, 00:05:10, Serial0/0 D 10.5.0.0/22 [90/2172416] via 10.0.0.1, 00:00:48, Serial0/0 150.1.0.0/24 is subnetted, 1 subnets D EX 150.1.1.0 [170/2172416] via 10.0.0.1, 00:24:31, Serial0/0 |
| R3#show ip route eigrp 10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks D 10.0.0.0/30 [90/21024000] via 10.0.0.9, 00:27:12, Serial1/1 D 10.5.0.0/22 [90/20514560] via 10.0.0.14, 00:01:20, Serial1/2 150.1.0.0/24 is subnetted, 1 subnets D EX 150.1.1.0 [170/20514560] via 10.0.0.14, 00:25:03, Serial1/2 |
Task 5
EIGRP supports route leaking when summarizing, which allows for greater flexibility as far as path control is concerned. When summarizing, EIGRP allows you to ‘leak’ or advertise more specific routes encompassed by that summary, ensuring that traffic destined to the leaked subnet is sent to the router that leaked the route by virtue of the longest-match rule. This task is completed on R1 and R4 as follows:
| R1(config)#access-list 1 permit 10.5.0.0 0.0.0.255 R1(config)#route-map LEAK permit 10 R1(config-route-map)#match ip address 1 R1(config-route-map)#exit R1(config)#route-map LEAK deny 20 R1(config-route-map)#exit R1(config)#interface serial 0/0 R1(config-if)#ip summary-a eigrp 100 10.5.0.0 255.255.252.0 leak-map LEAK R1(config-if)#exit |
| R4(config)#access-list 4 permit 10.5.3.0 0.0.0.255 R4(config)#route-map LEAK permit 10 R4(config-route-map)#match ip address 4 R4(config-route-map)#exit R4(config)#route-map LEAK deny 20 R4(config-route-map)#exit R4(config)#interface serial 0/0 R4(config-if)#ip summary- eigrp 100 10.5.0.0 255.255.252.0 leak-map LEAK R4(config-if)#exit |
Following this configuration, the routing tables on R2 and R3 show the following entries:
| R2#show ip route eigrp 10.0.0.0/8 is variably subnetted, 6 subnets, 3 masks D 10.0.0.12/30 [90/2684416] via 10.0.0.1, 00:17:43, Serial0/0 D 10.5.3.0/24 [90/21026560] via 10.0.0.10, 00:01:12, Serial0/1 D 10.5.0.0/24 [90/2172416] via 10.0.0.1, 00:04:02, Serial0/0 D 10.5.0.0/22 [90/2172416] via 10.0.0.1, 00:13:21, Serial0/0 150.1.0.0/24 is subnetted, 1 subnets D EX 150.1.1.0 [170/2172416] via 10.0.0.1, 00:37:04, Serial0/0 |
| R3#show ip route eigrp 10.0.0.0/8 is variably subnetted, 6 subnets, 3 masks D 10.0.0.0/30 [90/21024000] via 10.0.0.9, 00:39:19, Serial1/1 D 10.5.3.0/24 [90/20514560] via 10.0.0.14, 00:01:18, Serial1/2 D 10.5.0.0/24 [90/21026560] via 10.0.0.9, 00:04:08, Serial1/1 D 10.5.0.0/22 [90/20514560] via 10.0.0.14, 00:13:27, Serial1/2 150.1.0.0/24 is subnetted, 1 subnets D EX 150.1.1.0 [170/20514560] via 10.0.0.14, 00:37:10, Serial1/2 |
When using route leaking (leak maps) in conjunction with EIGRP manual summarization, it is important to ensure that you remember the following considerations:
If the leak-map keyword is configured to reference a nonexistent route map, the configuration of this keyword has no effect. In other words, the configured summary will still be advertised, based on the stipulated rules of advertisement, and the component routes remain suppressed.
However, if the leak-map keyword is configured, but the access list does not exist or the route map does not reference the access list, the summary address and all component routes are sent.
Task 6
This task is straightforward. If you ignore the ‘fluff’ and pay attention to detail you will see that the task simply calls for increasing the default EIGRP hop count limitation of 100 to 200 to accommodate devices in the new network. The default hop count is printed in the output of the show ip protocols command:
| R1#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 (route-map) NO-TAG-444 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: connected, eigrp 100 EIGRP NSF-aware route hold timer is 240s Automatic network summarization is not in effect Address Summarization: 10.5.0.0/22 for Serial0/0 Summarizing with metric 28160 Maximum path: 4 Routing for Networks: 10.0.0.1/32 10.5.0.0/22 Routing Information Sources: Gateway Distance Last Update (this router) 90 00:22:13 10.0.0.2 90 00:09:33 150.1.1.4 90 00:21:41 Distance: internal 90 external 170 |
This task is completed by configuring a hop count limit of 200 or greater on ALL routers:
| R1(config)#router eigrp 100 R1(config-router)#metric maximum-hops 200 R1(config-router)#exit |
| R2(config)#router eigrp 100 R2(config-router)#metric maximum-hops 200 R2(config-router)#exit |
| R3(config)#router eigrp 100 R3(config-router)#metric maximum-hops 200 R3(config-router)#exit |
| R4(config)#router eigrp 100 R4(config-router)#metric maximum-hops 200 R4(config-router)#exit |
Following this change, the show ip protocols command reflects the configuration:
| R1#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 (route-map) NO-TAG-444 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 200 EIGRP maximum metric variance 1 Redistributing: connected, eigrp 100 EIGRP NSF-aware route hold timer is 240s Automatic network summarization is not in effect Address Summarization: 10.5.0.0/22 for Serial0/0 Summarizing with metric 28160 Maximum path: 4 Routing for Networks: 10.0.0.1/32 10.5.0.0/22 Routing Information Sources: Gateway Distance Last Update (this router) 90 00:01:20 10.0.0.2 90 00:00:24 150.1.1.4 90 00:00:24 Distance: internal 90 external 170 |
Final Router Configurations
R1
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R1#term len 0 Current configuration : 1561 bytes R1# |
R2
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R2#term len 0 Current configuration : 906 bytes R2# |
R3
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R3#term len 0 Current configuration : 1249 bytes R3# |
R4
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R4#term len 0 Current configuration : 1541 bytes R4# |