More Highlights of IPv6:
The protocol must support unicast, anycast and multicast packet transmission ( broadcast is replaced by multicast)
Service Classes: the protocol must allow the network to associate packets with particular service classes (QoS)
Mobility: the protocol must support mobile hosts (ICMPv6 and DHCPv6)
Overhead:
- IPv4: 20Bytes (MAC) + 20B (proto) + 1460B payload
- IPv6: 20Bytes (MAC) + 40B (proto) + 1440B payload