Can't ping across VPN

[nightowl]

I recently installed Fedora Core 1 with PoPToP and the various other required packages needed. I can connect to the VPN server from the Internet but for some reason I cannot ping any other device on the network that is connected to the VPN server. I already set up another VPN server with the same version of PoPToP and it works fine. I can ping addresses on the VPN network without a problem. The only difference is that the working VPN server I acting as a gateway to the Internet so the Listening IP address (public i-net IP) is different from the server IP (IP of the NIC conencted to the private net). In the other case (Fedora) the server is behind a Dlink nat box with the PPTP port forwarded to the server. It also has the same IP for both the listening IP and server IP (192.168.1.21). Is that what is possibly messing everythin up or is it something else? I also copied the configs from the working server to the Fedora server (I did change the IPs though).

 

[nightowl]

anyone?