I asked on the Brocade forum, but it's largely been crickets there. I hoped someone here would have an idea.
One switch says: 23 Te 12/0/24 Up ISL segmented,(ESC mismatch, Distributed Config DB)(Trunk Primary)
The other switch says: 23 Te 54/0/24 Up ISL segmented,(ESC mismatch, Distributed Config DB)(Trunk Primary)
I saw that means, "The DCM Configuration DB is different on both the ends of ISL," but I have no idea how to resolve that.
Are you running fabric with logical-chassis mode. Did you set priorities on the rbridges to select selection order of the principal switch ? Did you make any configuration changes from anywhere else than on the principal switch (using cluster VIP to connect) ?
IF so, then message seems to point to a configuration difference between nodes hence a possible DB corruption.
When that happens, the switchs would rather not join the fabric then try merge and possibly cause configuration alterations and instabilities.
You should try to dig that message out on the net or in NOS guides. Maybe open a case with BTAC ?
But ultimately, I think you'll probably end up disabling one of the switchs, reset the config and rejoin it in the fabric.
I would suggest opening a TAC to get the full details on why it’s happening if the root cause not readily apparent. Typically remediating a these types of mismatches entails copying the default config to startup (triggers a reload) and rejoining the fabric.