Windows 2012 R2 Failover Communication Issues RRS feed

  • General discussion

  • Hi All,

    I're recently set up two win 2012 R2 servers with DHCP failover, in hot standby mode
    All was working great for a few weeks, handed over to support all ticked off no issues.

    Noticed when looking at a user dhcp issue, that one of the failover partnerships was showing as "Lost contact with partner"
    Digging deeper i can see now that the partner server in question is not listening on port 647, so its not sending/receiving comms for the failover, even though its up and working ok.

    Server DC1 - not listening on 647 - Failover relationship where this server is active and telling DC2 server "im up" is all good shows as Normal

    Server DC2 - working A-OK, listening on 647 - failover relationship where this server is activer and telling DC1 server "im up" is in "lost contact with partner" as it cannot connect to 647 on DC1 as its not listening

    Have restarted DHCP services, tried re-creating failover relationship - all to no avail - have searched high and low on google, cannot work out why 647 is not listening on DC1
    Turned off AV, Win FW set to prompt on blocks and log dropped packets, nothing is ever logged

    Does anyone have any other ideas as to what could be stopping the server from listening on this port?


    Wednesday, October 24, 2018 10:43 PM

All replies

  • Hi,

    Thank you for your question. I am trying to involve someone familiar with this topic to further look at this issue. There might be some time delay. Appreciate your patience.

    Thank you for your understanding and support.

    Best Regards,


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    Thursday, October 25, 2018 9:05 AM