How to configure LLT over UDP when you have more than 1 node at each site
The VCS install guide stays to set the broadcast address correctly for direct-attached (non-routed) links and for the links that cross an IP router, disable broadcast feature. This doesn't make any sense for "good" clustering when you have more than 1 node at each site and all examples in install guide are for 2-node clusters. Where you have more than 1 node at each site, then for every heartbeat link, nodes in same site (same subnet) will be directly attached, so install guide says set Broadcast, but nodes across sites (in different subnets) cross an IP router, so install guide says disable broadcasts. I am guessing you have to disable broadcasts for all links - can someone confirm?
Example suppose you have nodes A1 & A2 at site A and node B1 at site B with heartbeats:
A1 HB1: 10.8.5.1
A1 HB2: 10.8.6.1
A2 HB1: 10.8.5.2
A2 HB2: 10.8.6.2
B1 HB1: 10.9.5.1
B1 HB2: 10.9.6.1
So for node A1, it has a direct HB to A2 (in same subnet) and a routed heartbeat (in different subnet) to B1, so I think you need to disable Broadcasts.
I also don't understand statement on VCS install guide which says:
If the LLT private links are not on different physical networks, then make sure
that the links are on separate subnets
Lastly, I assume you cannot mix LLT over UDP with LLT over Ethernet, so in my example, I presume you have to use exclusively LLT over UDP.