Returning unused ASNs (was: IPV6 renumbering painless?)

Fri Nov 19 13:28:27 UTC 2004

Hi Ryan,

On Nov 18, 2004, at 11:10 pm, Ryan O'Connell wrote:

[...]

> At least for RIPE-issued AS#s, it's damned near impossible to give 
> them back once they've been used for peering.
>
> As a result of mergers, I've been left with AS16102 that's no longer 
> required but it's referenced from a number of other ASes as a result 
> of having been used for peering in the past. Some of the ASes it's 
> been reference from are abandoned (Company no longer exists as AS 
> isn't in the global routing table, or it exists and is still peering 
> but the owner has no BGP clue left on staff) which means I can't 
> delete it from the database.
>
> I've bought this up with a couple of people and I believe it's been 
> discussed in the appropriate RIPE WGs, but AS# exhaustion isn't 
> currently regarded as a pressing enough issue that anyone has thought 
> up a suitable solution. I guess when we do start running *really* 
> short on AS#s, RIRs will start being much more aggress reclaiming 
> unused AS#s and we'll probably see quite a few suddenly become usable.

Unfortunately, it can be difficult to remove references to an AS 
Number. Especially when the maintainer of a referring object has 
disappeared.

That being said, we do get a steady trickle of AS Numbers returned. 
When there a hanging references, we do our best to help remove them.

Once we cannot find any references to an aut-num in the RIPE database 
we will make the ASN available for re-assignment. This takes a minimum 
of three months. In some cases it can take considerably longer.

We are happy to help people return unused and unneeded resources to the 
available pool. Just let us know and we'll get the process started.

Regards,

-- 
leo vegoda
Registration Services Manager
RIPE NCC