All domain controllers in the following site that can replicate the directory partition over this transport are currently unavailable. Site:%1 Directory partition:%3 Transport:%2

Site:%1
Directory partition:%3
Transport:%2

The directory partition could not be replicated because all the bridgeheads in the site are considered stale. The Knowledge Consistency Checker (KCC) cannot reach an entire site because the bridgeheads are not responding. Corresponding NTDS KCC 1311 events will be logged.

Possible causes include:

• The bridgeheads are down.
• The bridgeheads cannot replicate.
• An IP connection does not exist between the sites that use SMTP replication.

To troubleshoot the problem, do one or all of the following:

• Verify that there are enough bridgeheads for a given domain. If necessary, add additional bridgeheads.
• Check the status of inbound replication on the bridgeheads in the site. If inbound replication cannot be completed, troubleshoot why the bridgehead is not responding.
• If this is an IP connection issue between the sites that use SMTP replication, no user action is required.