Multiple NIC card question

  • Thread starter Thread starter Richard King \(SCA\)
  • Start date Start date
R

Richard King \(SCA\)

W2k Adv
2 Intel pro server adapters


Both nics are connected to the Internet but two different networks. How can
i get windows to use one over the other by default. Right now it is only
using one, but not the one i want :) I saw Interface Matric under advance
settings... what does that do?
 
Hi Richard,
By default the computer will use the network card that has the default
gateway to communicate with networks it does not have static routes for. It
should be noted that the GUI will allow you to specify default gateways for
both NIC cards, but in reality you only get one of them. The NIC with the
highest binding, if both have default gateways, is the NIC that will
specify the default gateway. The interface metric will not alter this
behavior.

A better question to ask at this point would be to try and figure our what
exactly is to be accomplished with this as there may be a way to do this
that will work the way you want.
--
Curtis Koenig
Support Professional
Microsoft Clustering Technologies Support
MCSA, MCSAS,MCSE, MCSES

This posting is provided "AS IS" with no warranties and confers no rights.
Please reply to the newsgroup so that others may benefit. Thanks!
--------------------
 
thank you for the reply.

I have two NIC cards which both have public IP's for two different networks.
they also each have one gateway.

i want w2k to only use (to talk to other servers 'outgoing') one of the
nics. the other is there for backup and is what our DNS server is listing
on. I just want the server to use a particular NIC by default. if that nic
goes out, it will use the other. It is doing that now. But the default is
not the one i want. I could just switch the settings.. but i thought it
would be better to understand how w2k picks which card to use for out going.

thanks.
 
Hi Richard,
If the 2 NICs are on the same network this can cause browsing issues, but
as it is 2 different networks that should not be a problem. If you want
redundancy on the same network I would suggest you look into NIC teaming.
However, now that I understand a bit more about your configuration I can
talk more to this specifically.

Each NIC will be used exclusively when a packet for that network is being
sent. For example if the two networks are 192.168.1.0 and 10.0.0.0 any
packet for the 192 network will go out that card and the same is true for
the other. The only time a decision needs to be made is when a packet must
be sent to an unknown network, no static route and not on either of the
bound networks. In this case the card with highest binding order with a
valid default gateway will be used. I stated it in my first post but I
think it warrants repeating; it does not matter how many default gateways
you specify, Windows will only use one of them and the adapter with the
highest binding order will always have its default gateway used.

I hope this helps illuminate what your trying to accomplish.


--
Curtis Koenig
Support Professional
Microsoft Clustering Technologies Support
MCSA, MCSAS,MCSE, MCSES

This posting is provided "AS IS" with no warranties and confers no rights.
Please reply to the newsgroup so that others may benefit. Thanks!
--------------------
 
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