Connection broken over internet

  • Thread starter Thread starter Matt Palmer
  • Start date Start date
M

Matt Palmer

Hi,

we have a terminal server (W2K) that's working fine over the LAN on
a small network (two clients), also W2K. Another user connects over
the internet on a broadband connection, and this used to work fine,
but now the connection breaks very rapidly, saying there may be a
network error. Sometimes there's enough time to log in for a few
minutes. I've replicated the problem from home on a W2K box, so it
seems likely that it's something to do with the network or server.

The server has just had ZoneAlarm Security Suite installed on it,
with the software firewall component configured to let port 3389
through. It also runs Exchange 5.5 and OWA, all on a public facing
internet address with a hardware firewall, whose configuration hasn't
changed in several millenia. I can ping the server fine, and use OWA
and other services with no problems - it's just terminal services that
has the problem.

I played with the configuration last night. I removed the license
key from my registry, but that had no effect. I also reduced the MTU
on the server to see if any router black hole problems were causing
it, at which point I thought I'd sorted it, as I managed to have a
very long session after I'd rebooted the server with no problems at
all. This morning, the situation is worse than before - the
connection breaks while still showing the windows log in screen.

I can see quite a few posts about WAN connection's breaking, but few
solutions aside from the suggestions about black hole routing and
license managers... Does anyone have any ideas about this?

Regards,

Matt Palmer.
 
Hi,

thanks for the suggestion. I've set the KeepAlive, KeepAliveTime,
KeepAliveInterval and the TcpMaxDataRetransmissions, but it doesn't
seem to have improved the situation. I've also replicated the problem
connecting from a Windows XP client, so there's definitely something
going on here at the server end, or with the immediate network. It's
strange that it doesn't seem to affect other services like OWA, but I
guess that http is a connectionless protocol.

I'm going to try completely removing ZoneAlarm, as that's the only
thing recently installed on to the server. I suppose I could try
dropping the MTU again - it's set at 1400 right now.

Cheers,

Matt Palmer.
 
Hi,

we removed ZoneAlarm, and the terminal server connections remain
stable now. I have no idea why ZoneAlarm was affecting connections
like this; it's not as if they were totally blocked - just that they
were incredibly unstable. I'll get on to ZoneAlarm's technical people
about this.

Cheers,

Matt Palmer.
 
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