I have a Windows 2003 SBS and using Routing and Remote Access with 2 network cards - one connects to the Internet and the other connects to the LAN. RRAS handles Internet access providing NAT and Basic Firewall. I've setup the server to act as a PPTP VPN server. Users can dial in but it can be unreliable. For example, today I've connected in fine for about 10 minutes. I've then disconnected then reconnected a little later and it will work for about 30 seconds then routing will stop - I am still connected but ping to the server drops. This happens what seems randomly and on different machines with different routers/connections to the Internet. Can anyone provide a checklists of things to verify? So far I've checked the following using the web and Microsoft documentation - open port 1723 in RRAS on the WAN interface, MS recommends creating a 0.0.0.0 (network id), 0.0.0.0 (mask), 0.0.0.0 (gateway) static route for NAT, checked no outbound and inbound filters on either WAN or LAN interfaces, checked DHCP pool is not full, gone through SBS wizard initally for remote access (it doesn't seem to do everything), going through MS wizards and documents making sure the basics are configured correctly. One thing I couldn't find any information on - how to I ensure IP protocol 47 (GRE) is being allowed through. Since it is a protocol you don't open tcp 47 on the WAN interface so how do you configure RRAS in this scenario to allow it? Thanks for any help you can give.
