Announcing a /19 from a /16

Mon Jul 5 21:51:58 UTC 2004

> The response I got back was that this was impossible since ISPs require an
> announcement of the /16 the /19 would come from.  I have done work with ISPs
> before (and have read the NANOG list for many years) but haven't heard of
> such a requirement nor can I find any standards that indicate the same
> thing.
> 
> Does anyone have requirements of a /19 announcement requires the /16 to be
> there as well?  The company has plenty of /16s that it uses internally that
> are not being announced on the Internet at all.

The /19 is big enough to not get filtered by the majority. I don't know of any
specific "rules" or "do's and don'ts" that prevents you from announcing such a
space as long as you have a) permission from the /16 administrator (which you
claim to have), b) non-private-AS number announcing it and perhaps c) register
it in a popular IRR database (i.e. ALTDB, RADB).

BGP advertisement really isn't a rocket science. What you announce and what the
majority accepts is what the internet sees.

-J

> 
> Thanks-
> 
> -Eric
> 

-- 
James Jun                                            TowardEX Technologies, Inc.
Technical Lead                        Network Design, Consulting, IT Outsourcing
james at towardex.com                  Boston-based Colocation & Bandwidth Services
cell: 1(978)-394-2867           web: http://www.towardex.com , noc: www.twdx.net