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DHCP failover does not work if service is not servicing RRS feed

  • Question

  • I deploy failover DHCP scopes using Windows Server 2012 R2 in my environment and it works perfectly except for one scenario as follows,

    • Server A and B are in a failover relationship.

    • The servers reside in 2 different sites A and B.

    • Power is down in site B, server A takes over and starts releasing IP addresses.

    • Power is back in site B, the server is automatically started, however the network switch is not yet online. Server B triggers event 1041 "The DHCP service is not servicing and DHCPv4 clients because none of the active network interfaces have statically configured IPv4 addresses, or there are not active interfaces"

    • While the network switch is down, server A is servicing DHCP requests.

    • Network switch in Site B is online, Server B still is not servicing DHCP requests. However, server A detects that Server B is online and stops servicing requests.

    In this scenario, while the DHCP service is running on both servers, no IP addresses are serviced until the DHCP service on server B is restarted.

    Please advise.

    Monday, June 20, 2016 9:13 AM

All replies

  • Hi,

    >>In this scenario, while the DHCP service is running on both servers, no IP addresses are serviced until the DHCP service on server B is restarted

    It seems DHCP B doesn't work when you start the DHCP service before switch.If you restart switch first,then bring back the DHCP server B,will it work properly?

    Do you have multiple nic on server B?Or you could run BPA analyzer:

    Best Practices Analyzer for Dynamic Host Configuration Protocol

    https://technet.microsoft.com/en-us/library/ee941107(v=ws.10).aspx 

    It may caused by the DHCP Server service is corrupted.The workaround is restart DHCP service manually which you already knew.

    ________________________________________
    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.

    Tuesday, June 21, 2016 6:43 AM
  • Cartman,

    Yes, if the switch is started before the server things work just fine.

    There's only one NIC on the server B.

    I ran the BPA on the server and no warnings or errors related to such an issue was found.

    We faced the same issue before with a different server that starts faster than the network port. The server was not part of a failover and no IPs were serviced before the DHCP service is restarted. 

    I believe this could be a bug, the DHCP service can check regularly after Even 1041 and when the network is connected it can start servicing IPs.

    Tuesday, June 21, 2016 7:14 AM
  • Hi,

    >>I believe this could be a bug, the DHCP service can check regularly after Even 1041 and when the network is connected it can start servicing IPs.

    Thanks for sharing to us.Or you could follow The Windows Server User Voice to feedback on windows 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.

    Tuesday, June 21, 2016 8:40 AM