VPN fails over dial-up after 4 minutes

From: Bryan Linton (blinton_at_nospam.connellinsurance.com)
Date: 06/11/04 

Date: Fri, 11 Jun 2004 17:33:58 -0500

We're running SBS 2003 in a domain environment with about 30 users. We
began testing VPN access to our network over dial-up for our laptop users.
Our testing methodology:

- Boot the laptop while disconnected from the network.
- Log the user into his domain user account using cached credentials.
- Initiate a dial-up connection to the internet.
- Initiate the VPN connection using the shortcut called "Connect to Small
Business Server" (placed on the user's desktop by the client configuration
wizard)

So far, all works well. The VPN connection functions as it should, but
slowly, of course, since it's dial-up. But about four minutes into the
connection, it suddenly becomes unresponsive. The connection does not drop
(at least, not within the next few minutes; we haven't tested beyond that).
If we disconnect and reestablish the VPN connection -- using either the same
dial-up connection or a freshly estabished one; it doesn't seem to make a
difference -- we get another four minutes before it stops responding again.
I have varied the connection load from almost none to constant, full
bandwidth usage, with no difference. If I set a continuous ping to a node
on the internal lan, it replies fine up until four minutes is reached (give
or take 5-10 seconds). Then, the ping suddenly says, "request timed out"
(note that it does not say, "destination host unreachable".

We have tried the same thing from other laptops and desktops within our
organization using the same testing methodology. The client OS in all cases
is either 2000 Pro or XP Pro. We've even wiped a new laptop and done a
clean, manual install of XP Pro, freshly installed with the applications we
use, and no extra fluff. The results are identical.

Here's the kicker...if I go home and establish a VPN connection over my
broadband connection, it works fine. I used it for a couple of hours last
night and the connection never went south. So at this point, I can only
imagine one of two things: either it occurs only with dial-up connections;
or, some common software or service used in our office is contributing to
the problem (I don't have any of the agency software installed at home). I
plan to test further this weekend by using a dial-up connection at home to
connect.

Incidentally, from home I used the "Connect to Small Business Server"
method, and a manually configured VPN using XPs built-in VPN capabilities.
No difference.

Our network is protected by a SonicWall firewall with 1:1 NAT going to our
SBS.

Any help is appreciated...our NT4 Terminal Server is recently no more, and
the owner is NOT happy that our new solution isn't working for him. Heh,
and I'm stumped.

Thanks in advance!

Bryan

Relevant Pages

  • RE: Strange VPN Porblem
    ... I understand that one laptop can not access ... Please disable the XP firewall, and ensure there is no connection limit ... Please manually create a VPN connection via the following KB and then ... Try to access share folder via IP address (i.e. ...
    (microsoft.public.windows.server.sbs)
  • Re: Novice trying to setup VPN on XP with Linkys Router
    ... my office vpn on my laptop. ... I have even tried to delete the connection and adding it ... The modem is connected to a wireless router. ... home) and I want to use the Windows XP VPN feature. ...
    (microsoft.public.windowsxp.work_remotely)
  • Re: VPN fails over dial-up after 4 minutes
    ... > install of XP Pro on it, alongside his existing 2k Pro installation. ... > VPN connection to the SBS over both broadband and dial-up connections. ...
    (microsoft.public.windows.server.sbs)
  • Re: Is there a path around VPN?
    ... On the corp VPN I can use remote desktop to hop over to another ... I suspect it is trying to resolve on the corp DNS, ... I use a laptop for my VPN connection. ...
    (alt.internet.wireless)
  • Re: VPN disconnects after 3 - 6 minutes
    ... > VPN connection is disconnected after several minutesVPN connection is disconnected after several minutes. ... > corporate VPN running on a Compaq nc2400 dual core laptop. ... > disconnect because it does not reload and try to reconnect. ...
    (microsoft.public.windowsxp.work_remotely)
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