Cannot make connection with RAS server behind firewall.

John N · Guest

I have been struggling to get my remote access server to work. The symptoms
are somewhat inconsistent, and I’m guessing that I missed something major
here.
I have two servers behind my firewall, a netopia 3386-ENT. One is providing
web and mail services, and the other is a domain controller. Both are W2K3
fully patched.
Our ISP issued us a /248 network giving us 6 usable IP addresses.
The netopia is part of an enterprise network comprised of three site to site
VPNs, both connecting to this network. The VPNs connect using a PPTP
connection.

I’m trying to get users to authenticate to the domain controller using RAS,
and I’ve assigned one of the public IP addresses to pass PPTP back to the
domain controller’s private IP address. Most of the time, it doesn’t even
establish a connection. Sometimes it does, but only one person can use it.
Of course, if I tell the router to pass all PPTP connections back to the
domain controller’s internal address, none of the VPNs work.
I’m stumped. I’m pretty sure that this is a firewall issue, as the VPN
connections work fine from inside the network.

Thanks for your help in advance.