Fixed or random interface identifier for IPv6 random random Random interface identifier for IPv6 x:x:x:x specify interface identifier for IPv6 (random|((\d+){1,4}:){3}(\d+){1,4}) Peer interface identifier for IPv6 random calling-sid ipv4-addr x:x:x:x Interface identifier for IPv6 random Use a random interface identifier for IPv6 ipv4-addr Calculate interface identifier from IPv4 address, for example 192:168:0:1 calling-sid Calculate interface identifier from calling-station-id (random|calling-sid|ipv4-addr|((\d+){1,4}:){3}(\d+){1,4}) Accept peer interface identifier