1Optional: 2 - ipv6 traceroute to handle 464 transitions 3 4known problems/assumptions: 5 - does not handle ICMP types other than echo/echo reply 6 - does not handle protocols other than ICMP, UDP, and TCP 7 - assumes the handset has its own (routed) /64 ipv6 subnet 8 - assumes the /120 or /128 ipv6 subnet it generates can use the nat64 gateway 9 - assumes the nat64 gateway has the ipv4 address in the last 32 bits of the ipv6 address (that it uses a /96 plat subnet) 10