BGP Question - how do work around pigheaded ISPs

Tue Feb 13 04:40:09 UTC 2001

On Mon, 12 Feb 2001, Bill Nickless wrote:

> The question seems (in my opinion) to be whether registries are delegating
> netblocks that can be further subdivided, or not.
> 
> That is, some ISPs hold that if a registry has allocated /16s in some
> space, those allocations should not be subdivided by the allocatees.  If a
> registry is allocating /19s minimum in some other space, then the
> allocatees cannot and should not split that space and advertise longer
> prefixes.

All of this talk has me wondering about our network.  It's much smaller
than most of yours and according to the CIDR report, the only thing it
says we should aggregate is a single /24 out of the /19.  It is being
announced for testing purposes and by the end of the week, the testing
will be over and it will no longer be announced.

My question however is along the lines of splitting the /19 up by swipping
it out to BGP speaking customers who are announcing /24's, /23's, /22's,
etc.  The announcement needs to be made by them (from my understanding --
which may be wrong) for their multi-homing diversity to work.

If I add an aggregate statement to our config, is it going to aggregate
those /24's, etc that our BGP speaking clients are announcing to us into
our main /19 announcement?

This is something that I've been thinking about for a while and want to
sure we're doing the technically sound thing.

> In practice, how have corporate divestitures been handled by the
> registries?  Have organizations with portable netblocks been able to split
> them up and get new allocations from the registries, following the
> corporate reorganizations?

It is my understanding (again, perhaps flawed) that legacy allocations
were settlement-free but, if an organization has say a legacy B, is only
using a /18 of it and wants to do the right thing and return the B in
exchange for an /18 in CIDR space, they now get to pay for the /18 just
because they wanted to do the right thing.  I know if we had legacy space
we'd hang on to it for financial reasons if none other.

Someone correct me if I'm wrong on this.  

---
John Fraizer
EnterZone, Inc