Odd routing problem

[westmanm]

Here's a fun one. I have a 2621XM that was doing NAT with had F0/0 connected to a cable modem and F0/1 connected to us and a county government routing by way of a secondary address.
Now, I've added another interface with a 16+1 switchcard and I tried moving the internal connections to the switchcard and leaving the county link on F0/1. The router could ping addresses at the county, but computers on the LAN couldn't. They could however get to the Internet.
I couldn't get routing to work until I moved the line from F0/1 to the switch card and added it's address as a secondary IP. Now, everything works.

Any ideas as to why this routing will only work if I have them on the same logical port?

Thanks
Mike

 

[jimmyzz]

Mike,
It may be your seconadry address on the Fa0/1 that may be causing confusion in your route table. Post your config so we can gain a better understanding of your topology and perhaps we might be able to isolate the problem.

JimmyZ