Announcing a /19 from a /16

Mon Jul 5 21:50:30 UTC 2004

 > > 
> > Hi-
> > 
> > I'm working on a project within a large corporation and asked 
> > their network folks about getting a /19 from one of their 
> > /16s.  I wanted it to avoid NAT and any possible overlapping 
> > from using RFC1918 addresses.  This project gets connected to 
> > the internet at different times throughout the year at 
> > different locations through different ISPs.  I would announce 
> > the /19 for a short period of time, maybe a month or so.
> > 
> > The response I got back was that this was impossible since 
> > ISPs require an announcement of the /16 the /19 would come 
> > from. 
> 
> Maybe one of the (fairly rare, from what I see) actors that 
> ingress filter
> (or takes into account those small few that does) by 

strict 

> allocation

border

>? (What
> prefixes are yopu talking about?)
> 
> mh
> 

;)

mh

> 
> > 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.
> > 
> > Thanks-
> > 
> > -Eric
> > 
> > 
> > 
>