AS Numbers unused/sitting for long periods of time

Tue Jan 2 22:56:13 UTC 2018

Once upon a time, James Breeden <James at arenalgroup.co> said:
> I'm amazed at the number of AS numbers that are assigned, but not actively being used. I'm not talking just like they are offline for a week or month, this is complete non-use of the AS in the global routing table within *years*. They are completely abandoned resources - Whois data is inaccurate by 5-10 years, no routeviews data in the same time period, the owning organization (if you can find it) scratches their heads about responding whether they use it or not, etc.

I know of two (from a former job) that pre-date ARIN that haven't been
used since 1999 because those two companies no longer exist (nor AFAIK
does any successor company).  The whois information is bogus at this
point, but I couldn't prove that.

I expect that AS numbers allocated by ARIN and other current RIRs are
not abandoned like that (since they charge annual fees, and I assume
they reclaim for non-payment), so the number of abandoned AS numbers is
probably not growing significantly (and would not grow beyond the
pre-RIR pool).

With 32 bit AS numbers though, what's the point of making an effort to
reclaim the old AS numbers?  BGP4 has been shown to handle alternate
length AS numbers, so if somehow 4 billion are allocated, it probably
won't be a big deal to extend BGP again.

-- 
Chris Adams <cma at cmadams.net>