SOLVED Error 809, L2TP VPN, windows 7.

OK guys i have a problem. i have setup a vpn, and it works just fine over PPTP, but when i try to connect via L2TP i get error 809... i have opened up / forwarded everyport for VPN in general, and L2TP as far as i know... im just pulling my hair out now!

It connects just fine via L2TP if i point to the server via the lan ip address... but whats the point of that, i want to connect via l2tp outside my lan! So it just looks like its a port that i need to open / forward.

so far i have

VPN pass through on PPTP, L2TP, IPsec all enabled

4500,500,50,51,1700-1723 all forwarded to the VPN server.

yet when ever i try and connect via L2TP outside the lan i get "error 809" .... if i let it connect via PTPP it connects just fine, but i need L2TP.

Well i fixed it.... guess it has to do with NAT-T devices .... a simple registry setting on the client side fixes the issue and my VPN now works like a charm over L2TP

http://support.microsoft.com/kb/926179

Nice find, thats a bit obscure. I don't suppose a whole lot of people are doing VPN with windows behind a NAT device however. Or at least I'd think most businesses at least would be hosting their VPN headend in a DMZ which then passes certain things safely through to the internal side of the network - that sort of setup would coincide with Microsoft advised best practices and work around the security concerns involved with your current approach:
http://support.microsoft.com/kb/885348/en-us

You could likely do that too, but whatever you put in the DMZ to do your VPN stuff would need to be dedicated, as you wouldn't want much else running and accessible externally.

I.M.O.G. said:

Nice find, thats a bit obscure. I don't suppose a whole lot of people are doing VPN with windows behind a NAT device however. Or at least I'd think most businesses at least would be hosting their VPN headend in a DMZ which then passes certain things safely through to the internal side of the network - that sort of setup would coincide with Microsoft advised best practices and work around the security concerns involved with your current approach:
http://support.microsoft.com/kb/885348/en-us

You could likely do that too, but whatever you put in the DMZ to do your VPN stuff would need to be dedicated, as you wouldn't want much else running and accessible externally.

Click to expand...

ya no real point to go crazy... this is just a home vpn that allows me to access home lan away from home, while at school n whatnot.

But i must also note that even WITH the server setup as a DMZ, i got the same issue, so either the router still played a part in it, or i just dont have a certian setting right... either way its working now with just ports forwarded over L2TP