Re: nested prefixes in Internet

[Niels Bakker <niels=nanog () bakker net>]

* vas () mpeks tomsk su (Victor Sudakov) [Sun 20 Nov 2016, 03:07 CET]:
> I have reports that in case (2), some operators (e.g. Rostelecom) 
> don't accept the /24 or even /23 prefix on the grounds that it is 
> part of a larger /19 route already present in the routing table.
>
> Could they have a reason not to accept these more specific prefixes 
> other than a whim?

If you announce a prefix you must deliver traffic sent to addresses 
covered by it.  You don't go announcing 0.0.0.0/0 to your peers either.

If a customer takes a /24 and announces it elsewhere, a transit 
provider runs the risk of accepting inbound traffic without having 
the possibility to bill their customer for it if it accepts more 
specifics from e.g. a peer.


        -- Niels.