When you restart C*, you should have an entry in the logs which look like this that indicates it defaults to v4:
INFO [main] 2021-07-28 20:45:31,178 StorageService.java:650 - Native protocol supported versions: 3/v3, 4/v4, 5/v5-beta (default: 4/v4) I'm hoping someone else here on the mailing list can give pointers as to why a 3.11 node would advertise v3. I've been code-diving and scratching my head. I can't think of a scenario that would lead to this: [cqlsh 5.0.1 | Cassandra 3.11.5 | CQL spec 3.4.4 | Native protocol v3]
