I should have stated that I tried icmpv6, UDP, and TCP traceroute with the same results. Looks like Cogent is not returning TTL expired IPV6 packets within their core. I can only guess that this is a result of using 6PE and propagating the IPV6 TTL into MPLS.
Clinton On Sun, Nov 3, 2013, at 09:47 PM, Joe Abley wrote: > "Traceroute packets" is extremely vague. As a general rule, if you > want to discover a complete path between endpoints that are expected > to communicate using 80/tcp, trace the route using 80/tcp. > > (Not that it's ever expected to see protocol-specific drops in a core > or across a transit or peering edge.)
