2600:: No longer pings https://mailman.nanog.org/pipermail/nanog/2024-April/225388.html It appears that 2600:: no longer responds to ICMP. This seems to have happened around Friday 5th 13:40 UTC. 2600::, a IP address owned by the Sprint network (Now since acquired 2600:: is also used to be the address of sprint.net, now sprint.net has no v6.
===$ 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
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/ )
one honk maybe more