Undocumented protocol change in pfsync ?
Yesterday I tried to update a cluster of two devices from 2.3.4 to 2.4.2.
After the slave installs the new version, pfsync no longer works. So when the addresses swung, I lost a bunch of connections.
I took a closer look at the problem and found that definitely no states were exchanged. After the master had the new version everything worked again without problems.
Was the protocol changed again for pfsync? I could not find anything in the documentation or release notes.
Any time there is an upgrade, especially across operating system versions, there is always a possibility that will happen. It doesn't always affect everyone, but you can never rely on pfsync working during a significant OS update.