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Moving DHCP Server To A Different Windows Domain On The Same Netowrk RRS feed

  • Question

  • I have inherited a network that consists of 2 Windows AD Domains. My goal is to eliminate the older domain that is made up of windows XP clients and Server 2008 servers. I have already completed upgrading OS on clients and member servers and joining them to the new domain. The main questions that i have are:

    1. DHCP for my entire network is running on the older domain (original domain). What is the best way to remove DHCP from the old domain and add DHCP to the new domain. Looking for the quickest/easiest way to accomplish this. Can i turn on DHCP on a 2012 R2 server on my new domain and set the same DHCP settings as the current DHCP server and then remove the older DHCP server. (set the lease time to be very short and then remote restart my clients)? Would my clients find the new server after restart or after lease expires?

    2. There is currently a trust setup between both domains. What is the best way to demote all DC's on the old domain without causing any issues on the new domain. I eventually would like to upgrade the OS on these servers and join them to the new domain as member servers.

    I am looking to do this very soon as the issues between both domains have caused a lot of network issues with DHCP and DNS.


    Donald J. McDonough

    Wednesday, June 1, 2016 7:25 PM

Answers

  • Hi Donald,

    1.In case the DHCP server holds different other roles (like file server,etc) you can migrate this like any other computer using the ADMT.

    ADMT Guide: Migrating and Restructuring Active Directory Domains

    https://technet.microsoft.com/en-us/library/cc974332(v=ws.10).aspx

    If it is just a dhcp server you can either export DB , then migrate the server re-authorize and import configuration or you can just create a new server inside destination domain install DHCP role configure scopes and make it available for the clients and decommission old one. 

    2. When the client's IP address lease get to 50% duration,it will send a DCHPREQUEST packet to the last server,if it doesn't get reply,when lease get to 87.5%,client will send DHCPDISCOVER packet,and accept any available DHCP server.

    ________________________________________
    Best Regards,
    Cartman
    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.


    Thursday, June 2, 2016 3:07 AM

All replies

  • Hi Donald,

    1.In case the DHCP server holds different other roles (like file server,etc) you can migrate this like any other computer using the ADMT.

    ADMT Guide: Migrating and Restructuring Active Directory Domains

    https://technet.microsoft.com/en-us/library/cc974332(v=ws.10).aspx

    If it is just a dhcp server you can either export DB , then migrate the server re-authorize and import configuration or you can just create a new server inside destination domain install DHCP role configure scopes and make it available for the clients and decommission old one. 

    2. When the client's IP address lease get to 50% duration,it will send a DCHPREQUEST packet to the last server,if it doesn't get reply,when lease get to 87.5%,client will send DHCPDISCOVER packet,and accept any available DHCP server.

    ________________________________________
    Best Regards,
    Cartman
    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.


    Thursday, June 2, 2016 3:07 AM
  • Thanks for the answer. 

    I have HP Procurve switches on my network. My Core is also an HP Procurve. Should i need to worry about IP helper address between VLAN's if I plan on giving the new DHCP server a different IP address than the previous DHCP server on the old domain?

     


    Donald J. McDonough

    Thursday, June 2, 2016 12:05 PM
  • Hi Donald,

    >>if I plan on giving the new DHCP server a different IP address

    Of course you should make sure the IP Helper address is set to the new DHCP server when you use VLAN.

    ________________________________________
    Best Regards,
    Cartman
    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Friday, June 3, 2016 1:39 AM