Cannot ping interface.

After moving house I have just setup my lab routers & switches in order to get my studies underway again and to my surprise it wasn't working as I left it. I had OSPF running between my three 2611XM's and multiple VLAN's on the switches. Anyway, after some troubleshooting I have managed to identify the issue to lie with a particular interface on one of the 2611's. By connecting to the router via console the interface will ping, but it will not from the adjacent router within the same subnet.

I thought I'd take it back to basics, so I factory reset that router and connected directly to the interface in question via Ethernet from my PC. I set my PC to 192.168.1.100 and issued a simple "ip address 192.168.1.1 255.255.255.0" & "no shut". The interface shows as up/up but I cannot ping it from my PC. I did the same (using a different subnet) on the second interface on this router and I can ping it no problem.

Any ideas? Does it sound like the physical interface is shot?

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Comments

jason_lunde

do "debug ip icmp" on that router and try pinging that interface. See if it is even seeing the ping requests come in. Thats a good starting point.

Netwurk

Make sure you are using a crossover cable to connect to PC

sixarm

OK, a "debug ip icmp" shows nothing at all when I ping from my laptop. I can ping the interface from the router itself and debug shows this too.

I'm using a straight-through cable, but have tried a crossover too, it didn't make any difference. The same straight-through cable works fine when connected to the second FastEthernet interface on this router.

Other than reconfiguring my routers to not use this interface I don't know what else I can try.

chmorin

sixarm wrote: »

OK, a "debug ip icmp" shows nothing at all when I ping from my laptop. I can ping the interface from the router itself and debug shows this too.

I'm using a straight-through cable, but have tried a crossover too, it didn't make any difference. The same straight-through cable works fine when connected to the second FastEthernet interface on this router.

Other than reconfiguring my routers to not use this interface I don't know what else I can try.

Work your way up. Do you have link lights? If yes both of them or just one? Is the interface up/up in a "show ip int brief"?

If you can, configure two same media (fast ethernet or the like) interfaces identically, one of them being the one in question. If with the same configurations you can ping the other with your laptop, but not the one in question, then the switchport is bad. If you can ping neither of them, then you know where to start looking.

sixarm

chmorin wrote: »

Work your way up. Do you have link lights? If yes both of them or just one? Is the interface up/up in a "show ip int brief"?

If you can, configure two same media (fast ethernet or the like) interfaces identically, one of them being the one in question. If with the same configurations you can ping the other with your laptop, but not the one in question, then the switchport is bad. If you can ping neither of them, then you know where to start looking.

I have both link lights on and the interface shows as up/up. I have configured both FastEthernet interfaces identically, apart from IP address, and one will ping from my laptop and the other won't. If I look at this interface I'm not seeing any incoming packets.

The more I look at this, the more I'm thinking it's dead.