Changing the IP scope

Discussion in 'DNS Server' started by Ed Berlot, Nov 12, 2009.

  1. Ed Berlot

    Ed Berlot Guest

    We are slowly but surely running out of IP space (poor decision was made a few years back) and we are slowly migrating to a Class B address.

    Right now my PC's IP would be on the class B address (10.5.x.x) while my DNs Servers are on and 101

    Routing between the 2 networks is handled by the firewall, so that works like a charm.

    This is where I get little lost?

    Obviously using a different IP space my DNS server at is not going get updated.

    So 2 questions

    1) Would it make sense to create another DNS server and forward any requests outside of the 10.5.x.x address space to the server

    2) If I don't do #1 what are the ramifications to my workstations?


    EggHeadCafe - Software Developer Portal of Choice
    IE Behaviors To Turn Keywords Into Hyperlinks
    Ed Berlot, Nov 12, 2009
    1. Advertisements

  2. Hello Ed,

    If you use 10.5.x.x with a subnet mask (65534 clients) and running
    out of addresses, i would use a new subnet and setup routing correct and
    your DNS servers should be able to support them also.

    Personal i ouwld make the subnet smaller, you have a real big broadcast domain,
    with a lot of not needed traffic.

    Best regards

    Meinolf Weber
    Meinolf Weber [MVP-DS], Nov 12, 2009
    1. Advertisements

  3. in message
    This is not really a DNS question, rather a networking question.

    Nonetheless, you can simply use a /23 ( which will provided up
    to 512 hosts, instead of your current /24 ( that is currently
    providing upto 256 hosts. If you need more hosts, such as up to 1024, you
    can change the subnet to a /22 (, this way you don't have to
    change the IP scheme, just the subnet. Everything can keep their current IP,
    but you would increase the DHCP scope. You would also change the reverse
    zone subnet.

    Other than that, if you are already routing between two subnets (because the
    DNS servers are somewhere else), no change required.


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

    Please reply back to the newsgroup or forum for collaboration benefit among
    responding engineers, and to help others benefit from your resolution.

    Ace Fekay, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA
    2003/2000, MCSA Messaging 2003
    Microsoft Certified Trainer

    For urgent issues, please contact Microsoft PSS directly. Please check for regional support phone numbers.
    Ace Fekay [MCT], Nov 12, 2009
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.