* Check Router-ID
R3#show ip eigrp topology | in ID
IP-EIGRP Topology Table for AS(1)/ID(10.1.3.3)
R5#show ip eigrp topology | in ID
IP-EIGRP Topology Table for AS(1)/ID(10.1.5.5)
# Make some miss configuration.
R5#conf terminal
R5(config)#router eigrp 1
R5(config-router)#eigrp router-id 10.1.3.3
R5(config-router)#end
R5#clear ip eigrp neighbors
*Mar 1 07:48:58.318: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 10.1.245.2 (Serial0/0) is down: manually cleared
*Mar 1 07:48:58.330: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 10.1.245.4 (Serial0/0) is down: manually cleared
* Check if have any problems in routing table
R5#show ip route | in 10.1.3.0
D 10.1.3.0 [90/2323456] via 10.1.245.2, 00:00:50, Serial0/0
* R5 can see loop 0 of R3
R3#show ip route | in 10.1.5.0
D 10.1.5.0 [90/2323456] via 10.1.23.2, 00:01:11, FastEthernet0/0
* R3 can see loop 0 of R5
* Everything works ok until we got some external routes.
* When we do redistribution in the EIGRP we have problems.
# Configure new Loop 3 and redistribute into EIGRP.
R3#conf terminal
R3(config)#in lo 3
R3(config-if)#ip address 3.3.3.3 255.255.255.255
R3(config-if)#router eigrp 1
R3(config-router)#redistribute connected metric 1 1 1 1 1
* Now check R2 and R5 if they receive Lo 3 (3.3.3.3) and if not, why ?
R2#show ip route | in 3.3.3
D EX 3.3.3.3 [170/2560025856] via 10.1.23.3, 00:00:16, FastEthernet0/0
* R2 can receive and learn without problem about Loop 3 network.
* But on R5 we cannot learn this route, because loop prevention mechanism is working, Wen R5 receive updates from R3 in the EX Routes octet its see his own Router-ID.
R5#show ip route | in 3.3.3
R5#show ip route 3.3.3.3
% Network not in table
* R5 cannot learn about route and cannot advertise it to other Neighbors.
