2600:: No longer pings

[Ben Cartwright-Cox via NANOG <nanog () nanog org>]

It appears that 2600:: no longer responds to ICMP.

$ mtr -rwc 1 2600::
Start: 2024-04-06T10:53:41+0100
HOST: metropolis                                  Loss%
  1.|-- lcy02.flat.b621.net                          0.0%
[...]
  6.|-- ldn-b4-link.ip.twelve99.net                  0.0%
  7.|-- ldn-bb1-v6.ip.twelve99.net                   0.0%
  8.|-- nyk-bb2-v6.ip.twelve99.net                   0.0%
  9.|-- ???                                         100.0
 10.|-- sprint-ic301620-nyk-b5.ip.twelve99-cust.net  0.0%
 11.|-- ???                                         100.0

This seems to have happened around Friday 5th 13:40 UTC.

2600::, a IP address owned by the Sprint network (Now since acquired
by Cogent Communications) is a common (at least in my circles) IPv6
testing address, in a similar way that 8.8.8.8 or 1.1.1.1 is for a
quick address to remember that always pings, when such a address is so
easy to remember, you sometimes cannot help it becoming a "core
project" :) ( https://xkcd.com/1361/ )

2600:: is also used to be the address of sprint.net, now sprint.net has no v6.

This is sad, and I would either propose that Cogent/Sprint (I assume
2600:: is under the ownership of Cogent now) revive this address as
it's a very helpful testing address that is burned into the minds of
many. Or at the very least, I'm more than willing to tank the effort
of responding to ICMP!