HE.net's looking glass, by its infinite wisdom, has no IPv6 addresses for the router hostnames. Only A records exist. What's more infuriating is that if you manage to extract the IPv6 address of a router, the reverse DNS does contain a pointer to the IPv4-only domain name, so I need reverse reverse DNS (which is NOT forward DNS) to look up IP from PTR, which doesn't exist in this world. Solution: some routers have multiple addresses, so you can extract the "source" field in the command. Others? The best you get is the first hop, which is NOT the same router. The hack? Spin up a raw socket, send a request to LG to ping yourself, and read the ICMP packet. Thanks HE.net for making a reverse traceroute as convoluted as possible! So much for a IPv6-native provider.