jamie baddeley (jamie.baddeley) writes:
>
> Maybe I've missed something. Has there been a development where /24's can pulled out of 103/8 and then moved willy nilly (technical term du jour) by the hour from AS to AS and yet the GRT remains reasonably stable?

    Is there anything to prevent it from happening ?

There are at least two reasons to be cautious about whether it will work reliably. The first, to which Jamie alludes, is that the ability of the global Internet routing system to cope with an increased volume of updates as blocks of IP space move around is limited.

The second is the old-fashioned fact that router memory is cheaper than it used to be, but it's not free. You can only deaggregate the IPv4 routing table so far before sheer routing table size comes back as an issue.

It may be possible for carriers to deal to both of these by just not accepting long prefixes for some value of long. That would leave whoever's leasing out the space to provide routing for it, which is easy, and transit, which may not be. Or would leave users of leased small blocks of space with patchy reachability.

This is not an argument for an RIR necessarily to do anything about this. It is a reason not to assume that it's going to solve problems for large numbers of small users. For small numbers of large users it may work just fine, but they're probably the people who need this least.

- Donald Neal