Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
You may experience some slow load times, errors, and slight inconsistencies. We ask for your patience as we finalize the launch. Thank you.

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

simple routing question

I have a vlan firewalled by a pix. The pix is the default gateway.

I will need to route between two private IP address spaces. Can I connect a router with igrp enabled, for example, but not configured as the default gateway? Is proxy arp on the router going to recognize that the hosts on the vlan that are in separate IP address spaces need to connect?

  • Other Network Infrastructure Subjects

Re: simple routing question

Hi primavat,

no, proxy-arp is not going to work in this case, since your hosts will not do arp requests for destinations that are outside their subnet, they will just forward these packets to the default gateway.

So you have several options:

- define static routes on your hosts;

- on the pix, route the new address space to the new router. I'm not sure this will work with a pix, since it means it will route traffic out the same interface as it came in;

You could do the reverse though: make the router the default gateway for all hosts, and add a static default route on it towards the pix.

- move the existing hosts "behind" the router as well, so there are no hosts on the segment connecting the router and the pix;