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DHCP split scope question RRS feed

  • Question

  • Hi,

    We have Windows 2008 R2 domain. I have 2 DHCP servers and I set up the load balance by using split-scope.

    I noticed the IP exclusion range are different on the same scope on the two DHCP servers. I am confused why this happened.

    Please advise!

    Thanks in advance!


    Grace

    Tuesday, August 21, 2018 9:06 PM

Answers

  • Hi,

    If you have for example load balancing meaning 50/50 between two DHCP servers, the IP range you create will be identical on both systems. The exclusions will not be identical, as DHCPserver1 will be have 50% excluded and DHCPserver2 will have the other 50% excluded.

    When creating a DHCP Split-Scope, you configure the split percentage, and it will automatically calculate the exclusions depending on what percentages you configure it to.

    Best regards,
    Leon


    Blog: https://thesystemcenterblog.com LinkedIn:


    • Edited by Leon Laude Tuesday, August 21, 2018 9:56 PM grammar
    • Marked as answer by graceyin39 Wednesday, August 22, 2018 4:28 PM
    Tuesday, August 21, 2018 9:42 PM
  • Hi Grace,

    Can you share the Scope address and the exclusion ranges on both servers?

    Do you mean Reserved IP list? or are you referring to the IP addresses outside of the scope start and end IP addresses?


     

    Charlie Coverdale 

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

    Tuesday, August 21, 2018 9:54 PM
  • Hi,

    Specify which portion of the scope's address range will be hosted on each server. You may do this by moving the slider, manually entering the percentage values, or manually designating the bounds of the address ranges. An 80:20 ratio is frequently cited as optimal.

    Best regards,

    Travis


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    • Marked as answer by graceyin39 Wednesday, August 22, 2018 4:28 PM
    Wednesday, August 22, 2018 1:46 AM

All replies

  • Hi,

    If you have for example load balancing meaning 50/50 between two DHCP servers, the IP range you create will be identical on both systems. The exclusions will not be identical, as DHCPserver1 will be have 50% excluded and DHCPserver2 will have the other 50% excluded.

    When creating a DHCP Split-Scope, you configure the split percentage, and it will automatically calculate the exclusions depending on what percentages you configure it to.

    Best regards,
    Leon


    Blog: https://thesystemcenterblog.com LinkedIn:


    • Edited by Leon Laude Tuesday, August 21, 2018 9:56 PM grammar
    • Marked as answer by graceyin39 Wednesday, August 22, 2018 4:28 PM
    Tuesday, August 21, 2018 9:42 PM
  • Hi Grace,

    Can you share the Scope address and the exclusion ranges on both servers?

    Do you mean Reserved IP list? or are you referring to the IP addresses outside of the scope start and end IP addresses?


     

    Charlie Coverdale 

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

    Tuesday, August 21, 2018 9:54 PM
  • Hi,

    Specify which portion of the scope's address range will be hosted on each server. You may do this by moving the slider, manually entering the percentage values, or manually designating the bounds of the address ranges. An 80:20 ratio is frequently cited as optimal.

    Best regards,

    Travis


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    • Marked as answer by graceyin39 Wednesday, August 22, 2018 4:28 PM
    Wednesday, August 22, 2018 1:46 AM
  • Thanks for all of you. I think I got it. It is the percentages that confused me, but after thinking the image below, it does make sense why the exclusion shows up differently on each DHCP server.

    Thanks again!


    Grace


    • Edited by graceyin39 Wednesday, August 22, 2018 4:33 PM
    Wednesday, August 22, 2018 4:33 PM