Can't connect multiple sessions from same location to Contivity VPN

[speakspace]

Help!

I have a remote network of XP pcs which need to access specific host PCs at another site. Using the Contivity VPN client, I connect through a DSL connection. Any one of the PCs can connect just fine using this client, but I cannot connect multiple PCs at the same time ... I found a similar situation on another msg board, but with UNIX OS, so I can't get much out of that. Can anyone help?

Maybe the IP filter settings? I have no clue ......

 

[sah2129]

It sounds like this is one of the many network address translation issues. The problem is that when the server sends a keepalive or rekey request back to the client using UDP port 500, the NAT table does not know which session to send it to, so the packet, and eventually the session gets dropped. Some possible solutions are using IPC-NAT (IPSec aware NAT) or one to one NAT for IPSec users.