Problem with two NIC's in one server

Posted on 2009-04-09
Medium Priority
Last Modified: 2012-05-06
I have a server running Server2003 with IIS and Citrix Secure Gateway. It has a dual NIC. One NIC is configured with the IP of our Citrix web access page . The other is configured with the IP for the secure gateway. Both NIC's are configured with the same subnet, and default gateway. When I close the tcp-ip properties on either NIC, Windows gives this warning.
Multiple default gateways are intended to provide redundancy to a single network (internet/intranet). They will not function properly when the gateways are on two separate disjoint networks such as one on your intranet and one on the Internet. Do you want to save this configuration?"
I chose yes and everything seemed fine. After a while the web page became unavailable. Disabling and enabling or repairing the connection on the NIC's fixes the problem temporarily.
I have read that you cant have two NIC's in the same server on the same subnet.

Question by:PatTheThird
  • 4

Expert Comment

ID: 24109122
True, you cannot have multiple NIC's on the same subnet.  The server will be confused.
LVL 17

Accepted Solution

ccomley earned 2000 total points
ID: 24109222
I believe you CAN have two NICx on the same subnet but you do NOT need to specify the default gateway with each.

It's a misleading dialogue, the "default gateway" is NOT a parameter associated with the individual NIC but with the server as a whole.

So my first suggestion would be to remove the D/G parameter from one of the NICs and see how you get on.


If it still misbehaves, disable one NIC, and add the second IP address you had been using on it to the second NIC via the "Advanced" config. That way you can continue to use different IP addresses for your Citrix and IIS (presumabyl coz you might move one or the other service to a different physical server one day?) but the single NIC will carry all the traffic.

Author Comment

ID: 24109345
I tried removing the d/g from one NIC. This resulted in applications not launching.
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Author Comment

ID: 24109359
Would a reboot be necessary after making that change?

Author Closing Comment

ID: 31568614
You are the man

Author Comment

ID: 24110745
Moving both IP's to one NIC was the way to go for this situation.

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