I have just upgraded a version 145 IpFire to version 152. After the upgrade I had a problem with keepalived, which no longer configured red0 properly.
Turned out it went into fault state, because red0 does not support multicast.
The log said:
(WAN1) interface red0 does not support multicast, specify unicast peers - disabling
I could fix it by adding a unicast directive to the keepalived configuration. But this has been working for years without it.
What caused the change that made red0 no longer support multicast? Green and orange still do!
2: green0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
link/ether 00:0d:b9:49:d0:88 brd ff:ff:ff:ff:ff:ff
3: red0: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
link/ether 00:0d:b9:49:d0:89 brd ff:ff:ff:ff:ff:ff
4: orange0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
link/ether 00:0d:b9:49:d0:8a brd ff:ff:ff:ff:ff:ff
That’s curious. I had keepalived working on red until I upgraded and rebooted today. Only then did keepalived stop on red and complain that multicast was not supported.
Maybe keepalived did not actually check for multicast support before? But that would imply that it multicasted even when multicast support had been disabled.