I am now completely stumped with a VPN connection.
I have SBS2003 with ISA2006 at one end (Branch Office), and SBS2003/ISA2004 (Head Office) at the other. I can create a site-to-site connection from the Head Office to the Branch Office - works a treat once approriate rules were put in place. However, no matter what I do or how hard I try, I cannot get a connection through from the Branch to the Head Office (which is the one I need.)
Whenever I dial (either a RAS connection or by using the site-to-site creation wizard) the Head Office, I get an Error 628 disconnect. On the other hand, if I dial from a client at the Head office to the Head Office server, I can get a connection. I figure at lease the VPN end of the server is working.
I can connect from Branch to Home, so I guess I understand what I am trying to do.
The variables therefore seem to be the routers on either end. I have used the PPTP passthrough and checked the Port 1723 and GRE are opened. Using the Microsoft Windows Network Monitor, I can see the GRE packets at the Head Office Network, so I don't think I am blocking them. Just to be safe, I put the server in the DMZ in the hope that this would work. No luck.
I can telnet 1723, so I know that it is open. ISA logs show the packets being received, and then the connection is closed.
I have tried multiple users, ensuring that all are checked for dial in access.
Experience tells me that I am doing something really dumb, and have just spent the last how many hours going nowhere.
The setup is essentially:
Head Office
Private Adapater - 192.168.0.0-192.168.0.255 (server 192.168.0.21)
Public Adapter: 10.0.0.1 (server 10.0.0.21)
Router: Dlink DSL G604T - it makes the ADSL connection etc
Branch Office
Private Adapter: 192.168.1.0 - 192.168.1.255 (server 192.168.1.21)
Public Adapater: 172.16.0.0 - 172.16.0.255 (server 172.16.0.1)
The biggest clue I have so far is messed up routing. When I look at the public network on the Head Office Side, and I chose Add Adapter, I would have thought I would get only 10.0.0.0-10.0.0.255 plus loopback addresses etc. Instead, I get just about every address known to the universe. If I remove them and just use the 10.0.0.0 range, I lose external access to my web server on ports 80 and 443.
Router: billion 7404VGP 172.16.0.1
I would grately welcome any assistance possible in working out what on earth to do next.
Thanks
