aggregation & table entries

Joe Provo nanog-post at
Thu Oct 14 00:52:44 UTC 2004

On Wed, Oct 13, 2004 at 08:24:09PM +0000, bmanning at wrote:
> On Wed, Oct 13, 2004 at 12:54:44PM -0700, Kevin Oberman wrote:
> > > Date: Wed, 13 Oct 2004 18:43:45 +0000
> > > From: bmanning at
> > > 
> > > 	seems like a good lead in, so yes - i advocate folks only
> > > 	announce what they use.  may play old-hob on the ISP that
> > > 	likes to use some other metric for accepting announcements,
> > > 	(e.g. RIR or other routing registry DB) and will no doubt
> > > 	increase the tension on justification of proxy announcements,
> > > 	but overall, this seems to be a good goal.

Why? This is a serious question, as the bulk of network 
architectures with which I'm familiar have a wall between IGP and 
EGP, where the EGP is focused on _stable_ reachability & the IGP 
is concerned with optimal forwarding path within the AS.  Sinking
(or darknet detecting or...) unused space and happily shuffling
between used & unused without having to worry how it affects
your reachability [or its stability] is a generally a Good Thing.

> > Second, we don't simply assign address space sequentially from our
> > assigned spaces. We have an addressing plan that leaves the assignments
> 	so -IF- everyone followed your internal address assignment policies,
> 	scattering used space in a sparse matrix throughout the allocated pool,
> 	then announing a single prefix (the aggregate) makes sense.  Of 

"There are more internal policies on Teh Intarweb than are dreamt of in 
your philosophy." Internal policies are *internal*, and the usual wall
between internal and external policies means that maximal reachibility
can be guarenteed with minimal hassle and zero need to have to pick up
the phone and convince some random remote AS to change their policies to
accept your topology-of-the-week.  Seems that any actions that are
recommended should be internal policy/topology neutral, no?

Should I mention publishing the only the deaggregates-in-use essentially
rolls out the red carpet to hijackers letting them know prefixes you
*will*not*notice* that they borrow, except when the abuse calls and
subpoenas come rolling in?  Oh no, that's for later in the thread. 


             RSUC / GweepNet / Spunk / FnB / Usenix / SAGE

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