Forum Discussion

oogabooga_13071's avatar
oogabooga_13071
Icon for Altocumulus rankAltocumulus
Jul 20, 2016

Failover Multicast addressing best practice for vCMP

We have multiple vCMP F5 instances using the same default Failover Multicast address and port (224.0.0.245:62960). All vCMP F5 instances use the same vlan for high availability. What is the best prac...
application delivery
BIG-IP
Leonardo_Souza's avatar
Leonardo_Souza
Icon for Cirrocumulus rankCirrocumulus
Feb 09, 2017

Multicast is a destination address. If you want to change, at least the HA pair should be pointing to the same destination.

 

224.0.0.245 does not look to be a registered, and I guess is just because 245 is a conversation of F5 from hex to decimal (like they do with the default management IP). Here are some reserved IPs:

 

https://en.wikipedia.org/wiki/Multicast_address

 

I guess that the receiving devices will differentiate based in the source IP or source MAC, when they receive a packet from the peer device. You can take a tcpdump, use the wireshark plugin (as I think it has HA decoders), and check what happens.

 

https://devcentral.f5.com/wiki/AdvDesignConfig.F5WiresharkPlugin.ashx

 

I personally, never configure multicast. An HA vlan and management as unicast, should be more then enough. However, F5 does recommend that per this documentation:

 

https://support.f5.com/csp/article/K13915multi