Cluster service on members of the DAG seemed to have an issue last night. All looks ok now.
get-clusternetwork | fl reports everything as UP. (on all servers)
However, ClusterNetwork is reporting as FAILED for all member servers. Error is :-
Network "ReplicationDagNetwork01" has no network interface for server. Correct the physical network configuration so that each mailbox server has exactly one interface on each subnet. The use set-databaseavailabilitygroup with the -discovernetworks parameter to configure the database availability group networks..
This was working before so config is correct. All network interfaces are up. Should I run set-adatabaseavailabilitygroup