Working with 2 network connections

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raksasas

Limp Gawd
Joined
Dec 14, 2002
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I have a Windows Xp sp2 computer. The machine has 2 network cards now. I'll call them 1 (onboard) & 2 (PIC NIC). NIC 1 is connected to DPS which go through a router to a modem. NIC 1 has static IP (IP, Subnet, Gateway, and No DNS filled out). NIC 2 is connected to the domain. NIC 2 is DHCP. Each has a diffrent IP range.
Problem: To do updates, log on to the domain, etc with it I have to disable Nic 1 because it overrides NIC 2. Then I have to enable NIC 1 to get back to communicating with DPS

Is there a way to make where I can have both working togeather? So I don't have to disable NIC 1 to to get on internet, do updates, log on to the domain?
 
Your issue is that TCP/IP isn't designed to work with two default gateways. A default gateway is used to reach any IP address on the network that isn't on a local segment.

A typical DHCP configuration would assign a default gateway. Since you have one specified in your other NIC configuration, you probably have two default gateways assigned.

Since traffic routed to the default gateway set by DHCP won't actually reach the Internet, and traffic to the interior network can't actually reach its destination by going through the ingterface you have facing the Internet, the TCP/IP stack doesn't know where to send traffic. To see what a mess your routing table is, run "router print" at a command line. There will be two conflicting paths for each route.

You will need to manually assign an IP to the interior NIC and add persistent routes appropriate for reaching your interal address space. Do "route help add" for full command line details.

Your other option would be to remove the default gateway from the Internet facing NIC and add the persistent routes necessary to reach all Internet addresses (this woud typically be a lot more statements than just for your internal ranges).

Windows gives an error if you manually configure two NICs this way (assign the same settings you are receiving from your DHCP server to your internal facing NIC statically and watch Windows warn you about an unsupported configuration).
 
raksasas said:
Will useing the Bridge connections in XP do what I am wanting to do?
Click to expand...

If you are wanting to isolate your interior network from the subnet allowing Internet access, no.
 
Start adding some static routes, add the subnets for your domain stuff to the right NIC, and any thing else can go threw to the default gateway.

If you don't know how, well I don't know how to do it in windows myself.

Basically, when you know where something should be going, set a static route, if you don't know, then let the default gateway handle it. You might need to set a static IP though on the NIC you don't want to get the gateway from, or some how configure windows to ignore that directive for it (unsure as to how).
 
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