Windows Server 2008 r2 Domain Controller and multiple NIC ?

We have a new Windows Server 2008 r2 being set up as a domain controller.  There will be two of these on our network.  Each has 2 NIC cards.  

I was assuming that we could have both NIC's connected to our network for redundancy, each NIC with a unique IP.   However, a network guy here said that you don't want to have two IP's on one Domain Controller.

Is this right?  It seems weird that any server made for a high-availability network would be limited to using only one NIC...

(I was looking online for some documentation about how to use two NIC's on one DC, but haven't had luck.)

Thanks for your input.
Rob RudloffIT Development SpecialistAsked:
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What you're doing is termed "NIC Teaming".  See the following link:

From my understanding, what happens is you end up with 3 IP addresses to represent the server (similar to how a cluster works).

-1 IP for nic 1
-1 IP for nic 2
-1 IP to represent the "team".

The "Team" IP is the IP that all hosts will be pointed to.  Both nic 1 and nic 2 can handle traffic for the "team" ip address.

Your admin is correct in that you don't want your hosts seeing "server1" as IP address x.x.x.1 and x.x.x.2.  With the teaming solution, your hosts will see the server as x.x.x.3, but really it's the nics with x.x.x.1 and x.x.x.2 handling all requests sent to x.x.x.3 (the Team).

Make sense?

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That document likely doesn't apply:

•Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
•Microsoft Windows Server 2003, Standard Edition (32-bit x86)
•Microsoft Windows 2000 Service Pack 1
•Microsoft Windows 2000 Advanced Server
Creating Active Directory Users from a Text File

If your organization has a need to mass-create AD user accounts, watch this video to see how its done without the need for scripting or other unnecessary complexities.

I wouldn't say that
Gary ColtharpSr. Systems EngineerCommented:
Multihomed is not teamed so that invalidates the communication failure argument.

With 2008, you can do private clustering (teaming) and only DNS reference your team for server requests.

It is very feasible but you need to evaluate if it is necessary.

How many users are we talking about? How much traffic do you anticipate?


I don't know if Gary is going the direction I think he's going, but if he is, he's about to say "there's probably no need to do this", and he's correct.


It's good practice to have 2 domain controllers available per site.  Reason for this is if you have a single domain controller and you have a hardware failure, you now have no DC to authenticate against.  If you follow this 2 domain controllers per site model, there's really no need for NIC Teaming UNLESS a single NIC would be a bottleneck for you (very very unlikely).  If you suffered a NIC failure on a DC, the second DC in the site could pick up the slack until the broken DC is back online.  Fixing the broken DC would be as simple as plugging the network cable into the working port and assigning the IP address to that NIC.

In short, you may be going through this complex setup and not really gaining much.
Craig BeckCommented:
I'd say NIC teaming is a good way to go. If you have multiple NICs you can connect them to redundant or highly-available switches. This helps to minimize the impact of a switch failure for example.

Sure, if you don't have redundant switches it's not really worth the effort - maybe. I'd still consider it though as its an easy and cost-effective way to increase bandwidth and availability if the capabilities are there.
Rob RudloffIT Development SpecialistAuthor Commented:
Thanks, I will pass this on to the other guys here working on this.
We do indeed have 2 DC's (and a second redundant device of everything else) in two different buildings, so that may mean "teaming" is overkill for us.  Even though we have less than 50 users in 3 locations here, we may end up deploying "nic teaming" anyway, just for the experience.
Thanks for your insight.
-- Rob
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