This same issue happened in Los Angeles a number of years ago, but for IPv4 and v6. They need to setup sane BGP timers, and/or advocate the use of BFD for BGP sessions both customer facing and internal.

Ryan

On Nov 15 2020, at 5:58 pm, Matt Corallo <nanog@as397444.net> wrote:
Has anyone else experienced issues where Telia won't withdraw (though will happily accept an overriding) prefixes for
the past week, at least?

eg 2620:6e:a003::/48 was a test prefix and should not now appear in any DFZ, has not been announced for a few days at
least, but shows up in Telia's LG and RIPE RIS as transiting Telia. Telia's LG traceroute doesn't of course, go
anywhere, traces die immediately after a hop or with a !N.

Wouldn't be a problem except that I needed to withdraw another route due to a separate issue which wouldn't budge out of
Telia's tables until it was replaced with something else of higher pref.

Matt