OK, here is my setup:
ASA 5505 - 192.168.3.1
PIX 501 - 192.168.1.1
PIX 501 - 192.168.1.2
The ASA and the first pix device (192.168.1.1) are connected via site-to-site VPN on the ASA side and the connection works great. I can access hosts in either direction from either network.
I'm attempting to add the second pix device to the ASA's site-to-site configuration, but it's not working. I suspect it's because the devices are on the same subnet, but I'm hoing to find a workaround.
When I have both PIX devices setup for site-to-site on the ASA, the VPN works only for the connection that has the highest priority. The device with the lower priority can only ping the 192.168.3.1 network, but full network connections fail.
Is it possible to do this without changing the subnet on the second PIX?