I have already setup a (pptp)vpn daemon on our server, but nobody can connect to it, it seems that the GRE packets are Dropped or Rejected.
Any idea?
Anyone willing to test, pm me for username/pass...

What port is it running on? Maybe your firewall is blocking them, or it is a port that is filtered at teh network edge by SM

I'm using poptop server that listens on 1734 tcp port.
I'm sure that this port is open because My server receives the client request but the connectin will time-out after a while.
It seems during establishing pptp connections that uses GRE protocol all the packets are dropped.

We aren't blocking that port. Is your client running behind a firewall?

I'm usre that there is no firewall at the client side,
I've already install a poptop client(vpn client) on our matrix server,
the same problems occur when i try connecting to a working vpn server which the mentioned clients can connect to it with no problem.
I'm confused :shock:

The kernel need to enabled "pptp" otherwise connection will be drop when your client attempt to connect in. I tested once in my existing server from Rackspace.com, I wanted to install the one of them in my SM server too but no idea whether SM allow them?

I see no problem with it.