I'd be just as gutted if they ever pull the plug on ipv6.google.com <http://ipv6.google.com/> - it's my go-to "first attempt" for an IPv6 test. :-)
But this got me curious, so I grabbed a list of prefixes from [1] and decided to ping them all. Since I went through all that effort, might as well share the findings: $ for i in `cat list.txt`; do fping -6 $i -t 500 -r 0; done | grep 'is alive' 2409:: is alive 2a09:: is alive 2a11:: is alive 2a12:: is alive [<- 2a14:7:ffff::2]2a14:: is alive [1] https://www.iana.org/assignments/ipv6-unicast-address-assignments/ipv6-unicast-address-assignments.xhtml Tomas > 6. 4. 2024 v 12:00, 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!