In the land of Cisco HA, the MAC address is actually failed over during a transition. This makes for a fairly clean switch between devices. Vyatta however, doesn’t work that way. It simply moves the IP address and uses gratuitous ARP to get the switch(es) to recognize the change.
There is a way to have Vyatta mimic the MAC failover mechanism through the use of Pseudo Ethernet devices. These make use of macvlans to allow you to add multiple MAC addresses to a single interface. The basics are, you create a peth on both devices with the same MAC address but no assigned IP address and create a cluster service which fails over the IP address. The configuration is actually very simple.
In this example we create peth0 which is tied to eth0. The shared MAC address is 00:1f:aa:bb:cc:dd and the IP address we are going to failover is 192.168.1.1
set interfaces pseudo-ethernet peth0 link eth0
set interfaces pseudo-ethernet peth0 mac 00:1f:aa:bb:cc:dd
set cluster group test service 192.168.1.1/24/peth0/192.168.1.254
The end result is the active node will have an address on the peth and the standby node will not have any addresses. No address effectively make the secondary node inactive.