Did a TCPDUMP and here is what came out, seems liek its just stopped:
root@matterhorn:~# tcpdump -i vmbr0 -s0 -vv net 224.0.0.0/4 -n
tcpdump: listening on vmbr0, link-type EN10MB (Ethernet), capture size 262144 bytes
10:09:03.184827 IP (tos 0x0, ttl 64, id 46169, offset 0, flags [DF], proto...