Hi, I have a lab single node cluster with octopus installed via ceph-ansible. Both v1 and v2 were enabled in ceph-ansible vars with the correct suffixes. The configuration was generated correctly and both ports were included in the mon array. [global] cluster network = 172.16.6.0/24 fsid = bb204a5c-957d-4a06-a372-redacted mon_host = [v2:172.16.6.210:3300/0,v1:172.16.6.210:6789/0] mon initial members = aio1 mon_pg_warn_max_per_osd = 0 osd pool default crush rule = -1 osd_pool_default_min_size = 1 osd_pool_default_size = 1 public network = 172.16.6.0/24 I can also see that `ms_bind_msgr1` is enabled in the live config. root@aio1 ~ # ceph daemon mon.aio1 config show | grep msgr "mon_warn_on_msgr2_not_enabled": "true", "ms_bind_msgr1": "true", "ms_bind_msgr2": "true", However only v2 is binding netstat -tlnp |grep mon tcp 0 0 172.16.6.210:3300 0.0.0.0:* LISTEN 2039098/ceph-mon I have a client that only speaks v1 (ceph-csi) that can't talk to the v2 port 2020-06-15T09:49:51.330+0100 7f8776038700 -1 --2- v2:172.16.6.210:3300/0 >> conn(0x563bfd6b2000 0x563bde5ff600 unknown :-1 s=BANNER_ACCEPTING pgs=0 cs=0 l=0 rx=0 tx=0)._handle_peer_banner peer is using msgr V1 protocol 2020-06-15T09:49:52.258+0100 7f8776038700 -1 --2- v2:172.16.6.210:3300/0 >> conn(0x563bfd6b2000 0x563bde5ff600 unknown :-1 s=BANNER_ACCEPTING pgs=0 cs=0 l=0 rx=0 tx=0)._handle_peer_banner peer is using msgr V1 protocol What could be the reason for mon not binding to port 6789? Thanks Miguel