VPN causing lan routing issues

  • Thread starter Thread starter marsman
  • Start date Start date
M

marsman

VPN causing lan routing issues

I am trying to configure a VPN connection to a remote office.
Actually I should say I have configured it and it works. The problem
is when the connection is created people have problems accessing the
local server. Both locations have a server with one network card.
The local server is Windows 2003 the remote server is Windows 2000.

From my machine, before the VPN is connected, when I ping the local
server I get a responce from 192.168.168.1 which is the servers
address on our network. Once the VPN is connected, the local server
resolves to the local address of the VPN connection which can be
anything from 192.168.168.80-89 which is defined in DHCP.

Obviously the local VPN connection/adaptor is registering itself in
the DNS which is why the ping resolves to the new IP but why doesn't
it find the original entry for the server? How can I tell it not to
resolve to the VPN connection/adaptor?

The local server also hosts our Exchange Server so when people try to
connect with Outlook, it either takes forever to load and to open
emails or it doesn't find the server at all.

Without creating a host file what else can I do to resolve this issue?


The second issue I have deals with netbios name resolution. So
ignoring the above problem for a moment. The VPN works, it connects,
I can ping the remote server using its IP address on the server.
After adding a routing statement to my machine I can ping the remote
server by IP address. On neither machine can I ping by using the
server name. Anythoughts???


Thanks
 
You need to NICs to make this work correctly on two different subnets.
Something like this

Firewall ----VPN Server -----Internal LAN
 
This can be a problem if you use a DC (especially the first DC in a
forest/domain). When the DC acquires a second IP (for the VPN connection) it
can upset both DNS and browsing. There are several ways to attack the
problem. Have a look at KB 292822 and also 830063.
 
You need to NICs to make this work correctly on two different subnets.
Something like this

Firewall ----VPN Server -----Internal LAN
Click to expand...


Actually in the documentation from Microsoft they say that you can
configure VPN using one NIC.
 
Both articles you refered me to are about Windows 2000 Domain
controllers but my local DC is 2003 do the articles still apply. Will
they work on 2003? I noticed that there are separate groups for
Server 2003 does that mean there isn't a big difference between them
as far as networking goings?
 
I am not aware of any changes in 2003 which would change this problem.
It is basically a problem with dynamic DNS and the computer browser service,
which have not changed in 2003. It is actually related to the old multihomed
PDC problem from NT4.
 
Back
Top