Which scenario will cause automatic high availability (HA) synchronization to fail?

Which scenario will cause automatic high availability (HA) synchronization to fail?

• A. Different build versions
• B. Manually forced synchronization
• C. A force failover
• D. A configuration change to the primary NetScaler

Answer: (A)

Automatic HA synchronization relies on both Citrix ADC units running the same software build. When the builds differ, the data structures, state formats, and feature sets used by the two units can diverge, so the receiving unit can’t correctly interpret or apply the updates from the other side. That mismatch stops automatic synchronization from completing, even though the HA link is up. The other scenarios don’t inherently cause automatic sync to fail. Manually forcing synchronization is an explicit operation to push state, independent of the automatic scheduler. A forced failover changes which unit is active, but the synchronization mechanism can resume after the failover or during recovery. A configuration change on the primary is the kind of change that HA is designed to replicate automatically to the secondary, assuming the builds are identical.

Automatic HA synchronization relies on both Citrix ADC units running the same software build. When the builds differ, the data structures, state formats, and feature sets used by the two units can diverge, so the receiving unit can’t correctly interpret or apply the updates from the other side. That mismatch stops automatic synchronization from completing, even though the HA link is up.

The other scenarios don’t inherently cause automatic sync to fail. Manually forcing synchronization is an explicit operation to push state, independent of the automatic scheduler. A forced failover changes which unit is active, but the synchronization mechanism can resume after the failover or during recovery. A configuration change on the primary is the kind of change that HA is designed to replicate automatically to the secondary, assuming the builds are identical.