Re: BGP and The zero window edge

[Simon Leinen <simon.leinen () switch ch>]

Job Snijders via NANOG writes:
> *RIGHT NOW* (at the moment of writing), there are a number of zombie
> route visible in the IPv6 Default-Free Zone:

[Reversing the order of your two examples]

> Another one is http://lg.ring.nlnog.net/prefix_detail/lg01/ipv6?q=2a0b:6b86:d24::/48

>     2a0b:6b86:d24::/48 via:
>         BGP.as_path: 201701 9002 6939 42615 212232
>         BGP.as_path: 34927 9002 6939 42615 212232
>         BGP.as_path: 207960 34927 9002 6939 42615 212232
>         BGP.as_path: 44103 50673 9002 6939 42615 212232
>         BGP.as_path: 208627 207910 34927 9002 6939 42615 212232
>         BGP.as_path: 3280 34927 9002 6939 42615 212232
>         BGP.as_path: 206628 34927 9002 6939 42615 212232
>         BGP.as_path: 208627 207910 34927 9002 6939 42615 212232
>     (first announced March 24th, last withdrawn March 24th, 2021)

So that one was resolved at AS9002, see Alexandre's followup (thanks!)

AS9002 had also been my guess when I read this, because it's the
leftmost common AS in the paths observed.

> One example is http://lg.ring.nlnog.net/prefix_detail/lg01/ipv6?q=2a0b:6b86:d15::/48

>     2a0b:6b86:d15::/48 via:
>         BGP.as_path: 204092 57199 35280 6939 42615 42615 212232
>         BGP.as_path: 208627 207910 57199 35280 6939 42615 42615 212232
>         BGP.as_path: 208627 207910 57199 35280 6939 42615 42615 212232
>     (first announced April 15th, last withdrawn April 15th, 2021)

Applying the same logic, I'd suspect that the withdrawal is stuck in
AS57199 in this case.  I'll try to contact them.

Here's a (partial) RIPE RIS BGPlay view of the last lifecycle of the
2a0b:6b86:d15::/48 beacon:

https://stat.ripe.net/widget/bgplay#w.resource=2a0b:6b86:d15::/48&w.ignoreReannouncements=true&w.starttime=1618444740&w.endtime=1618542000&w.rrcs=0,1,2,4,10,12,20,21&w.instant=null&w.type=bgp

Cheers,
-- 
Simon.