One could implement a rudimentary IPv4 stack in a couple of afternoons. There is not much magic in parsing Ethernet / ARP / IPv4 / UDP. For IPv6, a node needs t

One could implement a rudimentary IPv4 stack in a couple of afternoons. There is not much magic in parsing Ethernet / ARP / IPv4 / UDP. For IPv6, a node needs to speak ICMPv6/NDP/MLDv2 which are all orders of magnitude more complex than their predecessors.