Core issue
Host on inside has default gateway set to the PIX and cannot ping other subnet on the inside.
Resolution
An example topology for this network setup is shown below.
Remote Internal network --- Router --- Inside network --- PIX --- Internet
The PIX will not issue Internet Control Message Protocol (ICMP) redirects. If a client is on the same network as the inside network of the PIX, and the client needs to access hosts on the remote internal network, then the client's default gateway needs to be set as the internal router on that segment. This will send all traffic from the client to the router. The router can route the traffic internally, or redirect traffic destined to the Internet to the PIX's inside interface.
