Event Logs 20291 : A BINDING-ACK message with transaction id: 17836 was sent for IP address: 192.XXX.XX.XX with reject reason: (Reject Reason Unknown) to partner server: DC1.group.com for failover relationship: DC1.group.com-DC2.group.com-3.

Question

Hi Experts! The customer was reported experiencing issue with DHCP failover relationships, which is the backup /secondary DHCP server was unable to perform and operate after the active server which is the primary encountered a failure and problem. During that time multiple users are reportedly confirmed disconnected with their computer desktops. Appreciate if you can give what causes of this issue and best recommendation . DHCP Server Failover relationship getting Error: The Primary DHCP server fails to switch to partner server for redundancy and found not available. Current Setup : • DHCP failover relationships is on Hot standby Mode • Maximum Client Lead Time is set to default 1 hour. • State Switchover interval is set to 2 minutes. ( By default, 60 minutes) • Addresses reserved for standby server set to 10% . ( By default, 5%) • Failover relationships is both configured on the DHCP server – DC1(Active)and DC2 (redundancy) • Partner /standby server set to DC2.group.com ( Redundancy ) Findings: • KB 2919355 has been installed. Based on Microsoft reference new release of Latest Roll up update for Windows 2012 R2 is![34853-20291.jpg][1]![34854-statistics.jpg][2] KB2955135 which is not installed. • Server1 and Serve2 do not have same Statistics. • The standby server did not take the ownership of the whole DHCP scope because they need to wait for 1 hour based on MCLT settings. However, DHCP still perform renew leases and lease IP address to client using its own percentage of the scope within this hour. [1]: /api/attachments/34853-20291.jpg?platform=QnA [2]: /api/attachments/34854-statistics.jpg?platform=QnA Checked the following: • Check the failover state in the scope properties. – Working • Verified DHCP failover Time Synchronization between 2 servers. • Run the command in Powershell > Systeminfo /fo csv | ConvertFrom-Csv | select OS*, System*,Hotfix* | Format-List • No other sign or indicator of misconfigure DHCP failover Relationship • No DHCP Scope Policies found error and missing. • Addresses Reserved for Standby Server is set to 10% , by default 5% according to Microsoft. https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/dn338976(v=ws.11) Thanks

Answer 1

Hi CandyLuo, I understand the pre-requisites need to be done before installing KB3000850. We need to remove failover relationship between the servers the restart them and then re-engage again. However upon checking KB3000850 is already installed after running the command to verify the installed hot fix (s) . systeminfo /fo csv | ConvertFrom-Csv | Select OS*, System*, Hotfix* | Format-List . Please see attached. After checking the other required update, I found my own solution not yet sure if this would fix the issue. So i consolidate all the requirement and known issue after applying and installing the updates. Solution : 1. Install Windows server update KB2955135 hot fix included in the November 2014 update Rollup. The issues have been fixed in the rollup update for Windows Server 2012 in KB 2919393 and for Windows Server 2012 R2 is KB 2919355. UPDATE: Some customers reported events 20291 getting logged even after applying KB 2919355. KB 2955135 (http://support.microsoft.com/kb/2955135 ) has been released to address this issue with DHCP failover. Customers who have DHCP failover deployments with Windows Server 2012 R2 and experiencing events 20291 should apply this patch. DHCP failover relation need not be recreated to apply this patch. DHCP server restart is required. Reference: KB 2919393 for Windows Server 2012 and KB 2919355 for Windows Server 2012 R2 – Installed https://learn.microsoft.com/en-us/archive/blogs/teamdhcp/dhcp-failover-fixes-in-kb-2919393-for-windows-server-2012-and-kb-2919355-for-windows-server-2012-r2 KB 2955135 for Windows Server 2012 R2 https://support.microsoft.com/en-ca/help/2955135/event-id-20291-is-logged-in-the-system-log-when-a-client-computer-is-m November 2014 update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 https://support.microsoft.com/en-us/help/3000850/november-2014-update-rollup-for-windows-rt-8-1-windows-8-1-and-windows Known Issue or Impact of Windows Update: a. You receive a 0x800f0922 or 0x80070005 error message b. Text for DNS events is not rendered in DNS Manager mmc snap-in Requirement in installing Windows update: KB 2955135 for Windows Server 2012 R2. To prevent any issues: a. You must install the updated servicing stack update 2975061 and restart the computer which is referring in November 2013 update rollup for Window 2012 R2. b. Hotfix 3042085 must be installed before applying the November 2014 update. - Installed already. 2. Re-Sync Windows Redundant DHCP Servers https://becomethesolution.com/a-binding-ack-message-with-transaction-id-dhcp-server ![35494-hotfix-installed.jpg][1] [1]: /api/attachments/35494-hotfix-installed.jpg?platform=QnA

Answer 2

I have the same issue, but I only get error message when an Apple device is trying to get IP. What did you do to fix this?