En forma similar a lo que sucede en IPv4, se ha definido un address-famliy nuevo para multicast IPv6. Esto permite tener una topología diferente para unicast y multicast en IPv6 y, mediante la respectiva address-family llevar la informacion de rutas en BGP.
The field ‘Total Lengh’which is part of the IPv4 header, is not found in the IPv6 header. Its function was to count the size of the packet payload plus the size of a variable lenght header. As the IPv6 header has a fixed size, the presence of this field is unnecessary.