/etc/vz/conf/212.conf
NETIF="ifname=eth0,bridge=vmbr0,mac=00:18:51:40:A5:E3,host_ifname=veth212.0,host_mac=00:18:51:C0:62:A4;ifname=vlan750,bridge=vmbr750,mac=00:18:51:16:EC:5F,host_ifname=veth212.750,host_mac=00:18:51:95:F1:7D"
/var/lib/vz/private/212/etc/network/interface
iface vlan750...