No internet using two network cards

[jeepcj236]

I am running Win Server 2003, dual nics. One nic is connected to the cable modem with static ip address, running nat/firewall. Other nic is running the private lan, 192.168.1.1, running dns, dhcp, and active directory. When I disable the lan connection, I can connect to the internet. When lan connection is enabled, no connection to the internet. I am thinking this may be a dns issue but not sure. Any help would be great.

TIA,
Benny

 

[imported_netman]

This could largely depend.. if you are doing DNS and DHCP on the inside, I would check the following..

1) what is the default route? I'm guessing your WAN side of the server is a static and public IP, and you have a gateway to point to your provider.. likewise on the LAN side is DHCP also assigning you a gateway?
route print or netstat -nr

2) what is your DNS set to? I'm not sure what or why you want to run DNS on the inside.. but like above, you may be getting assigned DNS servers from both side by DHCP.

 

[bwnv]

You might have firewall/nat looking at wrong nic.
Go here GRC.com
and try the leaktest and shields up after disabling lan side. Not saying you're dumb or anything, this happened to me once.

 

[volrath]

Metric is your friend. Change the metric of the internet to 1, and the LAN to higher than 1, IE 10.

When I did this in Win2k, removing the default gateway from the LAN NIC also had the same effect.

 

[jeepcj236]

you rock, took out lan nic gateway, everything works great!!