Advertising rented IPv4 prefix from a different ASN.

Fri Aug 5 13:41:59 UTC 2016

On 04.08.2016 21:39, Andrew wrote:
> Hello List,
> 
> I work for a medium sized ISP.  We are entering an agreement to rent
> some IPv4 space from a local higher education institution.  Being a
> multi-homed ISP we would like to advertise the rented prefix from our
> ASN.  The prefix that will be advertised is a smaller subnet from the
> higher educations block; they will continue to advertise the larger prefix.
> 
> What is the best way to accomplish this?  Is there any way of doing this
> without having to tunnel the traffic through the origin ASN?
> 
> I feel if we just adverse the prefix it get put on a bogon list for
> prefix hijacking.  This space is rented long term but they are not
> interested in reassigning the space to us.  They also want to keep
> advertising their prefix as one contiguous block.

Make sure proper route-objects exist. Should be no big deal then imho.
Others do it as well - also advertising the larger block from one ASN
and a smaller portion of it from another.

Kind regards,
 Stefan