Why can I ping an address with the standrard command but NOT with extended?

[ccsmith705]

I have a 7204 router with 3 fast ethernet interfaces, 3/0, 2/0 and 2/1. 3/0 connects to my network. 2/0 and 2/1 each connect to a 1604 router. I can telnet into the 7204 and ping the two 1604 routers using the standard ping command. I can also ping the one connected to interface 2/1 using the extended ping command and using the ip address of 3/0 as the source address. But when I try the same extended ping command to the router connected to interface 2/0 it never replies! HELP!!!

[mark-obrien]

You need to check the routing table in the router connected to 2/0 to see if it has a route to the IP address of 3/0. An alternative would be a default route pointing to the address of 2/0.

HTH

Mark

[ccsmith705]

Thanks for responding Mark,

I did check the routing table. It's very small only directly connected routes and static routes. The routes to the networks connected to 3/0, 2/0 and 2/1 all show up as directly connected routes.

Any other suggestions will be greatly appreciated.

Chris

[mark-obrien]

I meant the routing table of the 1604 connected to 2/0 of the 7204. The address of 3/0 should not be shown as connected on that router.

Mark

[ccsmith705]

Unfortunately that router does not belong to me and I cannot telnet into it. What about the fact that I can ping that router with the standard ping command. Doesn't that indicate it's routing table is working?

Chris

[mark-obrien]

When you ping with the standard ping command, the source address of the ping packet is the source adress of the outgoing interface, or 2/0 in your case. The 1604 responds to this because the source address is on a connected network. When you do the extended ping with the address of 3/0 used as the source, the 1604 apparently does not have that address in its routing table, so the ping fails.

You will have to get with the owner of that router to solve this issue. Specifically, ask that owner to show you the routing table, and look for the network address of 3/0 in the table.

[ccsmith705]

I will follow your advice and call them tomorrow. Thanks for the help Mark, I appreciate it.

Chris