DHCP not serving 2nd scope

Discussion in 'Server Networking' started by Bruce Johnson, May 28, 2009.

  1. Server 2008, I have a 192.168.5.x and 10.x.. when the 5.x fills, it doesn't
    start serving 10.x ip's...>????
    Bruce Johnson, May 28, 2009
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  2. Bruce Johnson

    Bill Grant Guest

    That isn't how it works. If it did, the machines in 192.168.5 would not
    be able to talk to the machines in 10.x and vice versa.

    What is the IP address of the NIC in the DHCP server? DHCP will allocate
    an address in the same IP subnet as the NIC which receives the request.
    Machines will only get a 10. IP address if the broadcast is received on a
    NIC with a 10. IP address.

    If you have multiple segments joined by routers, DHCP relay on the router
    will allow the machines in different segments to get the correct IP address
    for that segmen/subnet.
    Bill Grant, May 29, 2009
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  3. The nic of the server has both a 5.x and a 10.x ip on it.. this configuration
    worked for years under 2003R2, but just upgraded to 2008 and it stopped
    Bruce Johnson, May 29, 2009
  4. Curious, I can't see how this worked unless you had them superscoped, meaning the subnet mask combined them to be under one big subnet, unless you were using a DHCP agent. What's the subnet mask? Does it encompass both and ranges?

    Also, as Bill said, I can't see how two machiens on the same wired segment with one machine with an IP of say,, and another one on the same wired segment has an IP of would be able to communicate if they were given an IP configuration with a /24 subnet from this DHCP server, unlesss of course they would have a /22 subnet that would encompass them under one large subnet, otherwise they would need a router to be able to route traffic back and forth to them.

    Maybe it's something I am not immediately seeing, possibly based on the briefness of your post that doesn't have information on your design, the server setup, how many NICs, how subnets is it conneted to, etc. Can you eleborate on your network design to get a better understanding, please? Maybe that will help us understand why it is not working for you.


    This posting is provided "AS-IS" with no warranties or guarantees and
    confers no rights.

    Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSA Messaging, MCT
    Microsoft Certified Trainer

    For urgent issues, you may want to contact Microsoft PSS directly. Please
    check http://support.microsoft.com for regional support phone numbers.

    "Efficiency is doing things right; effectiveness is doing the right things." - Peter F. Drucker
    Ace Fekay [Microsoft Certified Trainer], May 29, 2009
  5. The superscope cured it. Thanks.

    Bruce Johnson, May 29, 2009

  6. Ahh, I had a feeling it was based on the mask.

    I recommend to keep the subnets a little closer, such as,,, etc, instead of using two widely split subnets. This will help with a mask's range, otherwise you have to increase the mask to encompass the two.

    Glad I could help.

    Ace Fekay [Microsoft Certified Trainer], May 29, 2009
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