KVM Guest can't connect to server by ssh non standard port


I have a linux VM called “A” virtualizated with KVM and networking with bridge (virtbr0) in host “H” (I don’t have any firewall enabled).

I have another server called “B” in other location, with ssh service listening on 1315 port.

I can access via ssh to server “B” from host “H” and from my desktop machine, but from VM “A” I can’t.

If I change listening port of server “B” to port 22, then I can access from VM “A”.

I think that the network interface virtbr0 is blocking the 1315 port, but I can’t find where.

Hope you can help me