Troubleshoot FTD HA Configuration State "Sync Skipped" in show failover state Output

Issue

A Firewall Threat Defense (FTD) High Availability (HA) pair displays the configuration state as "Sync Skipped" instead of the expected "Sync Done" status. This condition appears on both units in the HA pair and raises concerns about whether the configuration synchronization between the active and standby units is functioning properly.

Example (FTD active unit):

device# show failover state 
               State          Last Failure Reason      Date/Time
This host  -   Primary
               Active         None
Other host -   Secondary
               Standby Ready  Comm Failure             16:10:34 UTC Apr 13 2026

====Configuration State===
        Sync Skipped
====Communication State===
        Mac set

Example (FTD standby unit):

device# show failover state
               State          Last Failure Reason      Date/Time
This host  -   Secondary
               Standby Ready  Ifc Failure              15:17:58 UTC Apr 13 2026
                              management: No Link
Other host -   Primary
               Active         Comm Failure             16:10:34 UTC Apr 13 2026

====Configuration State===
        Sync Skipped - STANDBY
====Communication State===
        Mac set

Environment

• FTD 7.6.4. Other software versions are also affected.

• FTD in Active/Standby HA deployment.

Resolution

The "Sync Skipped" status does not indicate an error condition.

The table provides a list of the various configuration states and a brief explanation:

Configuration State String	Explanation
Sync Skipped	Active unit detected that running config hashes match between active and standby, so no config sync is needed. Both units already have identical configurations.
Sync Skipped - STANDBY	Perspective from standby unit of the matching config condition; both units confirmed they have identical configurations.
Sync Required	A configuration sync is necessary but has not yet started. Shown when the standby unit first joins the HA pair and the active unit has not yet determined whether the configs match, or when a config mismatch has been detected.
Interface config Syncing	Active unit is in the process of sending VLAN and interface-specific configuration to the standby unit.
Interface config Syncing - STANDBY	Standby unit is receiving and processing VLAN and interface-specific configuration from the active unit.
Config Syncing	Active unit is actively streaming the full running configuration bulk data to the standby unit.
Config Syncing - STANDBY	Standby unit is actively receiving and replaying/applying the full configuration data streamed from the active unit.
Sync Done	Active unit successfully sent the complete configuration and received acknowledgment from the standby.
Sync Done - STANDBY	Standby unit finished receiving, parsing, and applying all configuration commands from the active unit.
Ready for Config Sync	The standby unit has signaled back that it is ready to receive configuration. The active unit is now waiting to start sending the full configuration over to the standby.

Related Verification Commands

You can use these commands to monitor the configuration sync optimization:

device# show failover config-sync checksum 
My State: Active
Config Hash: eaec2c0e8f2176394bc74771bdf5779d

device# show failover config-sync status   
Config Sync Optimization is enabled

device# show failover config-sync configuration
My State: Active

device# show failover config-sync stats all
Current HA state          : Active
Config sync skipped
FREP_CMD sender count         : 26

device# show failover config-sync errors all
        No observed config execution failures.
device# show failover config-sync errors current
        No observed config execution failures.

Cause

The "Sync Skipped" status is typically the result of configuration sync optimization functionality in FTD. This feature enables the system to compare configuration hash values between the active device and the joining device. When the hash values computed on both devices match, the joining device skips full configuration synchronization and rejoins the failover configuration directly. This optimization ensures faster HA peering, decreases FTD HA upgrade times, and reduces the duration of a maintenance window. The "Sync Skipped" message indicates that this optimization process has determined no full synchronization is necessary, which is normal behavior when configurations are already in sync.

Related Content

• Config-Sync Optimization

• Cisco bug ID CSCwf23868

• Cisco Technical Support & Downloads

Revision History

Revision	Publish Date	Comments
2.0	08-Oct-2026	Recertification
1.0	05-Jun-2026	Initial Release