Share via

Windows Server 2012 DHCP Event ID: 20291

Question

Tuesday, March 17, 2015 3:16 PM | 1 vote

Hi,

We have a DHCP failover set up with the default settings.

We have always noticed numerous Event ID: 20291 errors in the Event Log. After following the instructions installing patches KB2919355 and KB2955135, deleting the failover relationship, and recreating it, we're still getting numerous errors with different scopes, and the error repeats repeatedly for the same IP. Sometimes users would get duplicate IP address error.

When we click on "Display Statistics" on various scopes for each partner, they show different numbers as far as how many IPs are leased by each.

Any ideas on what this could mean? We're ready to just remove the failover relationship completely and go back to split scope.

All replies (7)

Thursday, March 19, 2015 6:23 AM ✅Answered

Hi,

According to your description, my understanding is that DHCP failover with load sharing mode, Event Log displays numerous Event ID: 20291, and the error repeats repeatedly for the same IP.

As KB 2955135 mentioned that Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. If both servers are Windows Server 2012 R2, please install KB3000850(November 2014 update rollup for Windows Server 2012 R2), download link:
http://www.microsoft.com/en-us/download/details.aspx?id=44975

Note:
Before you install this update, you have to first remove the failover relationship, install the update to both DHCP nodes and restart them, and then reestablish the failover relationship.
                        
Best Regards,
Eve Wang

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 [email protected].

Thursday, March 19, 2015 9:28 PM

Eve,

Rollup package KB3000850 was installed. But we didn't break the relationship first.

We broke the relationship afterwards restarted, and then re-established the failover relationship. Would this cause any issues? Should we remove the rollup package, break relationship, reinstall rollup package, then re-establish the failover relationship?

We're still receiving the error in the Event Viewier.

Friday, March 27, 2015 9:37 AM

Hi,

As I know based on the description from the KB(update). Relationship should be first deleted, then install the update.

Or, you may try to delete the relationship first, then restart both DHCP servers, and try to rebuild the failover again.
        
Best Regards,
Eve Wang

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 [email protected].

Friday, August 14, 2015 6:40 PM

Hi Ngenuity,

I'm having the same problem. Did you try deleting the relationship from the IPv4 properties, Failover tab, then re-adding? Or did you go the route of removing the patch, then deleting the relationship, re-adding patch, and re-configuring relationship?

Thanks!

Tuesday, May 29, 2018 3:54 PM | 1 vote

Hi, Ngenuity, Did you ever resolve your issue. I'm experiencing the same issue, where patch had already been installed. Thanks

Tuesday, May 29, 2018 3:57 PM | 1 vote

Hi, Ngenuity, Did you ever resolve your issue. I'm experiencing the same issue, where patch had already been installed. Thanks

Monday, June 4, 2018 4:05 PM

We removed the failover relationship and recreated the load balanced relationship which seems to have resolved the issue. We also put in a scheduled task on one of the servers that will replicate any adds/mods/dels to that server's DHCP settings, with scope configurations, scope options, reservations, etc.

The task triggers on eventID 106 and 107 to execute the powershell script with the command Invoke-DhcpServerv4FailoverReplication -Force –ComputerName xyz