Connect failed through VPN

Question

I have a very strange problem in developing MFC programming.

I used connect() function in winsock.h in order to connect to my server with specified port. Everything is Okay in normal case, but when I used the VPN, then I could not connect to my server. GetLastError() was returned by 10060 - timed out error.

After that, I used ping command to my server - that was Okay and the connection status was very good - at most 400ms. So, I used telnet command to my server with the port - I could see the timed out error.

After I disconnected the VPN, telenet worked well.

It's strange for me... How can I solve this?

For more info : I'm using PacketiX and the port is 17006.

Answer 1

This probably has nothing to do with "socket programming", and everything to do with "network configuration".

Two strong possibilities:

1. The VPN has a firewall that's blocking your connection ... and/or ...

2. Your internal LAN has the same network numbers as your VPN's LAN (e.g. 192.1.168.xxx for both networks) and the stack can't route correctly while the VPN is on.

There are other possibilities, too.

STRONG SUGGESTION: Get a copy of WireShark and trace the calls going over the wire:

http://www.wireshark.org