Cluster. Multicast problem.

[Yuriy Droga]

I created cluster. Checked multicast. Added a node.
In the beginning everything works fine, but then after a while time - cluster crushed. After this i cheked multicast (omping), image below, and tcpdump.

tcp dump -i interface -s0 -vvv host multicastaddress

...mynode_hostname.5404 > multicastaddress.5405: [bad udp cksum 0xcde4 -> 0x15cb!] UDP, length 136...

Somebody has an idea, whats wrong?

 

[Alwin]

Let omping run for longer as multicast might be dropped after some time by the switch.
https://pve.proxmox.com/pve-docs/chapter-pvecm.html#_cluster_network

...mynode_hostname.5404 > multicastaddress.5405: [bad udp cksum 0xcde4 -> 0x15cb!] UDP, length 136...

Modern network cards have checksum offloading, tcpdump will not see that.