HA question

[suthomas1]

Good day,

In an upgrade scenario, will doing a failover cause a mismatch related issue if the primary f5 happens to run a different version than secondary f5.

it is a situation when upgrade is performed on one of the f5 and then failed over to make it active.

[eneR · Accepted solution]

If you don't jump major releases like from 13.x to 16.x the update and failover usually works fine. Make sure to do this work in a maintenance window... you never know. 😉

Follow this Guide: https://support.f5.com/csp/article/K84554955

Abstract:

Getting HA support during an upgrade

High availability (HA) communication using network failover functions between major software branches, but should only be used for the duration of the upgrade process. For example, a pair of BIG-IP systems running 11.5.3 and 12.1.1 can negotiate active-standby status using network failover. For more information, refer to K8665: BIG-IP redundant configuration hardware and software parity requirements.

Configuration synchronization (ConfigSync) does not operate between different major software branches. For example, you cannot synchronize configurations from a system running BIG-IP 11.5.4 to a system running BIG-IP 11.5.3. You must wait for both systems to upgrade before ConfigSync can operate. For more information, refer to K13946: Troubleshooting ConfigSync and device service clustering issues.