it should be a multicast problem because i solve it with using unicast..
Use unicast instead of multicast (if all else fails)
Unicast is a technology for sending messages to a single network destination. In corosync, unicast is implemented as UDP-unicast (UDPU). Due to increased network traffic...
I have 2 node in same vlan installed fresh proxmox 4.1.. I have succesfully added second node to my primary node. No errors everything was working fine than node2 was showing as offline!
Than i restarted corosync and pve-custer services on node2 and its working... and than 5 min later node2...