Multiple NICs On 2003 Causing Problems

Discussion in 'Windows Networking' started by CBerry, Jul 19, 2004.

  1. CBerry

    CBerry Guest

    Hello, I have 3 NIC cards in my server runnning 2003
    Enterprise Edition. This server is an active directory
    domain controller, DNS server, and DHCP server. Each NIC
    card has its own IP address. My problem is this: When I
    attempt to browse the network neighborhood it is extremely
    slow and on my XP machines I get permission errors. In the
    event viewer I get error NetBT 4319. I have read at that this is a problem with NetBIOS
    broadcasting the machine name across the network causing a
    conflict. Now, I have sone this before with 2000 server
    and had no problems....

    Anyways, they suggest to disable Microsoft Client And File
    Sharing on all but the one NIC. So, I say what the heck
    (though this should not have to be) and it works! The
    speed of nethood browsing is normal and no
    permission/unavailability errors. I think everything is
    fine... well... it is not. I now am not able to edit any
    group policy objects such as the Domain Controller Policy.
    I get an error: Failed to open the Group Policy Object.
    You many not have appropriate rights. Details: Windows
    cannot find the network path. I go to see if disabling the
    Microsoft Client and the File Sharing caused this by
    enabling the services on the second and third NICS again-
    lo and behold I can open group policy snap ins.... but the
    network lookup problems come right back.... There should
    be some "normal" way to fix this and I have been spending
    hours and hours trying to repair. Any help would be
    greatly appreciated!! Thanks
    CBerry, Jul 19, 2004
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  2. You're not supposed to run multiple NICs in a Domain Controller. SBS is an
    exception and is commonly used with two NICs, but using three is just
    begging for trouble. If those three NICs are all in the same subnet then you
    are really shooting yourself in the head.


    Phillip Windell [MCP, MVP, CCNA]
    Phillip Windell, Jul 19, 2004
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  3. CBerry

    CBerry Guest

    Thanks for the help, I was not aware you could not run
    multiple NICS. I never had a problem with 2 on the same
    subnet on 2000 ADV server. What if I want more bandwidth
    to the same server?
    CBerry, Jul 20, 2004
  4. Then you run faster NICs and faster cabling, or you do Server Clustering.
    Two nics don't do that. You can buy specialized NICs that come with special
    software to make the two NICs work together, but you can't do that with
    Windows itself.

    But even if you do that you still get the speed cut back as soon as it hits
    the first switch or hub. The hubs always "share" that bandwidth among ports
    and not "combine" bandwidth,...while switches will always "switch" packets
    to the matching MAC addresses they are intended for which means it will only
    use the one port and cable associated with the MAC address of the
    destination NIC, only use one NIC anyway. I suspect that very
    "high-end" switches have ways around this, but hubs just aren't usable at

    You had trouble with two NICs in the same subnet on 2000 but you just never
    knew it. It causes there to be two Default Gateways in the routing table,
    each on a different NIC without a way for the System to tell them apart and
    know which one it is supposed to use. But if instead you just put two IP#s
    of the same subnet on a single NIC this doesn't happen.
    Phillip Windell, Jul 20, 2004
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