You want to check the status of EIGRP on the router.
There are several useful commands for looking at EIGRP status. As we have seen throughout this chapter, the show ip protocols command displays a wealth of useful information:
Router1#show ip protocols
You can look at a routing table of only those routes that were learned via EIGRP by adding the eigrp keyword as follows:
Router1#show ip route eigrp
Another extremely useful EIGRP command displays a table of all of the adjacent EIGRP routers:
Router1#show ip eigrp neighbors
You can see information about the interfaces that exchange routing information by using EIGRP with this command:
Router1#show ip eigrp interfaces
This information is nicely augmented with the new show ip eigrp accounting command:
Router9#show ip eigrp accounting
And finally, you can view the EIGRP topology database as follows:
Router1#show ip eigrp topology
The precise output of the show ip protocols command varies, depending on what features are enabled. However, we have shown several examples of different output throughout this chapter:
Router1#show ip protocols Routing Protocol is "eigrp 55" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Serial0.1 filtered by (prefix-list) Inbound Default networks flagged in outgoing updates Default networks not 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: static, eigrp 55 Automatic network summarization is not in effect Maximum path: 4 Routing for Networks: 172.25.2.2/32 172.25.0.0 192.168.20.0 Routing Information Sources: Gateway Distance Last Update (this router) 90 5d23h 172.25.2.1 90 00:03:32 Distance: internal 90 external 170 Router1#
The standard command to view the IP routing table is show ip route. However, this will show you all of the IP routes, including static routes, connected routes, and routes learned through other protocols, as well as EIGRP routes. If you just want to see the EIGRP routes, you can add the keyword eigrp to this command:
Router1#show ip route eigrp D*EX 0.0.0.0/0 [170/91942912] via 172.25.2.1, 00:04:29, Serial0.1 Router1#
One of the most useful commands when troubleshooting EIGRP problems looks at the neighbor table:
Router1#show ip eigrp neighbors IP-EIGRP neighbors for process 55 H Address Interface Hold Uptime SRTT RTO Q Seq Type (sec) (ms) Cnt Num 1 172.25.2.2 Se0/0.2 7 00:25:16 641 3846 0 148 2 172.25.1.7 Fa0/0.1 80 1w0d 17 200 0 406 0 172.22.1.4 Fa0/1 12 1w0d 3 200 0 259 Router1#
There are several important pieces of information in this list. Obviously, it's useful to look at the IP addresses and interfaces. But it can also be extremely useful to look at the uptime. In this case, you can see that two of these neighbors have been up and stable for a week, but the third one was reset 25 minutes ago. The router will sort this output so that the most recent neighbors are at the top. This gives you an immediate way of seeing which neighbors might have problems.
Also useful in this output is the Q column. This tells you how many EIGRP packets are currently queued for this neighbor. If the router is consistently queuing EIGRP packets, then there may be a congestion or queuing problem with this interface.
If you think you see EIGRP congestion or performance problems like this, it can be useful to look at the interfaces in more detail:
Router1#show ip eigrp interfaces IP-EIGRP interfaces for process 55 Xmit Queue Mean Pacing Time Multicast Pending Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes Fa0/0.1 1 0/0 17 0/10 50 0 Lo0 0 0/0 0 0/10 0 0 Fa0/1 1 0/0 3 0/10 50 0 Se0/0.2 1 0/0 641 0/15 3163 0 Router1#
This command shows useful information, such as how many peers there are on each interface. It also tells you more about any possible queuing issues, breaking out exactly how many routes are still pending.
There is a useful new show command in IOS Version 12.3(14)T. The show ip eigrp accounting command gives you useful operational information about your EIGRP neighbors:
Router9#show ip eigrp accounting IP-EIGRP accounting for AS(55)/ID(172.18.5.9) Total Prefix Count: 50 States: A-Adjacency, P-Pending, D-Down State Address/Source Interface Prefix Restart Restart/ Count Count Reset(s) A 172.20.10.1 Se0/0 1 0 0 A 172.18.19.1 Fa0/0 39 0 0 A 172.18.19.4 Fa0/0 1 0 0 A 172.18.19.6 Fa0/0 6 0 0 Router9#
In this case, the output shows that most of the prefixes in the EIGRP routing table come from a single neighbor router. In this case, you will notice that the total of the Prefix Count column doesn't add up to the Total Prefix Count on the second line. The difference is due to prefixes that originate with this router.
The final two columns in this display, Restart Count and Restart Reset, are only relevant to the new maximum-prefix command, which is not discussed in this book because it is not available in most IOS feature sets.
Another useful command when debugging EIGRP problems is the show ip eigrp toplogy command. This command gives a view of the EIGRP topology table. This is useful because it often includes information about routes that EIGRP has received, but that the router isn't using for whatever reason. For example, if there is a similar route with a better administrative distance, such as a static route, the show ip route command will indicate only the static route. So this command allows you to look through the whole EIGRP topology table to see exactly why the other route is better:
Router1#show ip eigrp topology IP-EIGRP Topology Table for AS(55)/ID(172.25.25.1) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 0.0.0.0/0, 1 successors, FD is 28160, tag is 5 via Rstatic (28160/0) via Summary (28160/0), Null0 P 10.2.2.0/24, 1 successors, FD is 156160 via 172.22.1.4 (156160/128256), FastEthernet0/1 P 10.1.1.0/30, 1 successors, FD is 3845120 via Connected, Serial0/1 P 192.168.10.0/24, 1 successors, FD is 28160, tag is 5 via Rstatic (28160/0) P 192.168.30.0/24, 1 successors, FD is 156160 via 172.22.1.4 (156160/128256), FastEthernet0/1 P 192.168.20.0/24, 1 successors, FD is 2195456 via 172.25.2.2 (2195456/281600), Serial0/0.2 P 172.25.25.6/32, 1 successors, FD is 156160 via 172.25.1.7 (156160/128256), FastEthernet0/0.1 P 172.25.25.1/32, 1 successors, FD is 128256 via Connected, Loopback0 P 172.25.25.2/32, 1 successors, FD is 2297856 via 172.25.2.2 (2297856/128256), Serial0/0.2 P 172.25.1.0/24, 1 successors, FD is 28160 via Connected, FastEthernet0/0.1 P 172.25.2.0/30, 1 successors, FD is 2169856 via Connected, Serial0/0.2 P 172.22.1.0/24, 1 successors, FD is 28160 via Connected, FastEthernet0/1 Router1#
The EIGRP topology table also shows the successors for each route. The successor is the route that will be installed in case the better one goes away.