DHCP SuperScope

Posted on 2012-09-20
Last Modified: 2012-09-24
We are running out of DHCP addresses, so I created a super scope and tried to add a child but it wont. It errors with "the mask and range conflict with an existing scope"

Here is my configuration. Am I doing something wrong?

Scope 1 - - / mask
Failed Scope 2 - / mask

I thought the whole point of the superscope was to allow you to keep everything on one subnet?
Question by:ssites
    LVL 18

    Expert Comment

    by:Sushil Sonawane
    Add failed scope as / mask

    Author Comment

    If the mask is different wont it affect them accessing the network?
    LVL 12

    Expert Comment

    wouldnt you just increase the range of IPs under scope 1? The masks overlap the scopes

    Author Comment

    the range is from 1 - 254 there is no room to increase
    LVL 44

    Accepted Solution

    ryan is right - the original scope is too small.  The scope you have is effectively a /24 even though your mask is a /16, so you're using nowhere near all of the /16 you have available.

    If it's a Windows DHCP server you'll have to delete the scope and recreate it with a larger pool.  I'd guess you have active IP addresses between and (due to the second pool you tried to create), so why not create a pool of addresses from up to, then exclude - (you can do this as 2.255 and 50.0 are actually valid IP addresses within your range).

    Author Closing Comment

    ahh got it! Thanks guys I will do this

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    Highfive Gives IT Their Time Back

    Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

    This may not be a text book method to resolve VSS backup issues but it seemed to have worked on few of the Windows 2003 servers we had issues while performing a Volume Shadow Copy backup. If you have issues while performing a shadow copy backup usin…
    Many of us need to configure DHCP server(s) in their environment. We can do that simply via DHCP console on server or using MMC snap-in on each computer with Administrative Tools installed in a network. But what if we have to configure many DHCP ser…
    how to add IIS SMTP to handle application/Scanner relays into office 365.
    Access reports are powerful and flexible. Learn how to create a query and then a grouped report using the wizard. Modify the report design after the wizard is done to make it look better. There will be another video to explain how to put the final p…

    759 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    11 Experts available now in Live!

    Get 1:1 Help Now