Binding to specific ports is not supported, yet config & code tries to do so
Having ceph.conf say
public addr = 10.1.2.3:4567
Makes cosd try to bind multiple listening sockets to the same port. Without the line, it binds 3 sockets each on a different dynamic port. That config, without the port, does change the binds from 0.0.0.0 to the given IP address.
Either this should be supported, or ports should not be allowed there.