Why 1 VHID per CARP interface?

[alanbryan]

This link says that you can alias multiple IPs per CARP interface.  Yet in pfsense various posts in this forum all state that you must have one VHID per CARP interface/IP.  The gui only allows the selection of a single address for CARP VIPs too.

http://unix.derkeiler.com/Mailing-Lists/FreeBSD/questions/2007-12/msg00299.html

So, I'm just trying to figure out if this is wrong, a pfsense limitation, etc…  In the example in this link all the IPs would be found at the same MAC address (same carp0 interface), correct?  Yet in pfsense since each VHID is unique there is a unique CARP interface created and thus a unique MAC address per VIP.

Thanks for helping me to understand.

[dotdash]

pfSense does not support FreeBSD alias addresses via the GUI. See this for a manual method http://doc.pfsense.org/multiple-subnets-one-interface-pfsense.pdf
Alias addresses are in 2.0, but aliasing CARP interfaces is probably not supported. You'd have to test on a 2.0 snapshot.