VPN client behind NAT

From: Gary Armstrong (garyarm_remThis_at_testedgeinc.com)
Date: 01/07/05 

Date: Fri, 07 Jan 2005 06:45:33 -0800

Hello all;

I'm new to VPN and networking and could use some help.

I'm trying to connect to another company using the Windows 2000 default
client (client of choice by other company). The client returns error
721: Remote host not responding. The client sits behind a NATing router
managed by my ISP.

I'm pretty sure NAT is the problem, because if I use a dial-in
connection to my ISP the connection is successful. My ISP thinks their
VPN needs to handle NAT traversal.

Seems to me NAT should handle VPN not the reverse and I've read some
stuff at TechNet that seems to support that. (Of course I only half
understand and know that's dangerous) In particular:

"When a PPTP client is behind a NAT, a PPTP NAT editor is typically
used. A NAT editor is an additional software component on the NAT that
performs translation services beyond IP addresses, TCP ports, and UDP
ports."

It's the words "beyond" and "additional" that are bugging me.

I would like to know, If anyone else is doing what I'm trying. Beyond
that, If you can tell who's correct I'd appreciate the explanation.
Last, if you can point me at documentation or a better place to ask, I'd
  make use of that.

TIA
Gary

Relevant Pages

  • Re: Complete VPN Fundamentals and VPN Router RV042
    ... There is a new standard, colloquially known as NAT-T, which allows a client ... machine to use an IPSEC VPN through a NAT device to a host. ...
    (microsoft.public.windowsxp.work_remotely)
  • Re: IPSEC VPN NAT
    ... There is no problem with only one client behind a NAT-Device, ... There are a number of problems with using IPsec over NAT devices. ... The VPN server must be running Microsoft Windows ServerT 2003. ...
    (microsoft.public.isaserver)
  • Sonicwall VPN client question
    ... I was beating my head against a brick wall with my Pro-VX and VPN ... until the 6.3.1 firmware and the 8.0 VPN client - then it worked ... Now, however, it doesn't work through my NAT box anymore. ... I'm trying to find what I can do on my server to get this working ...
    (comp.security.firewalls)
  • Sonicwall VPN client question
    ... I was beating my head against a brick wall with my Pro-VX and VPN ... until the 6.3.1 firmware and the 8.0 VPN client - then it worked ... Now, however, it doesn't work through my NAT box anymore. ... I'm trying to find what I can do on my server to get this working ...
    (comp.security.firewalls)
  • Re: FTP Server setup... Im so close!
    ... > I have installed the Internet Information Services, etc, and have the FTP ... Your external client is trying to use Passive Mode. ... Since your server is behind NAT, ...
    (microsoft.public.windowsxp.network_web)
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