Reproduce by
set interfaces ethernet eth1 address '2001:db8:200:ffee::103:2/112' set interfaces ethernet eth1 vif 1000 address '2001:db8:200:ffee::104:2/112'
vyos@vyos# run show configuration commands | strip-private | match eth1 set interfaces ethernet eth1 address '2001:db8:200:ffee::103:2/112' set interfaces ethernet eth1 disable set interfaces ethernet eth1 duplex 'auto' set interfaces ethernet eth1 hw-id 'XX:XX:XX:52:f5:f9' set interfaces ethernet eth1 smp-affinity 'auto' set interfaces ethernet eth1 speed 'auto' set interfaces ethernet eth1 vif 1000 address '2001:db8:200:ffee::104:2/112'