[ppml] Draft 2 of proposal for ip assignment with sponsorship

Forrest forrest at almighty.c64.org
Fri Feb 28 09:53:24 EST 2003

On Fri, 28 Feb 2003, Alec H. Peterson wrote:

> > If you filter my /24 from my provider's aggregate, what exactly is the
> > point of me multihoming?   If I lose connectivity with that upstream,
> > you'll no longer be able to reach me because you won't hear my /24
> > announcement from my other upstream.  To me, it doesn't seem acceptable
> > to filter out multihoming /24's at all.  Creating a micro allocation
> > policy would seem to address this issue.  Create a block of addresses
> > that  /24's won't get filtered from, while still allowing everyone to
> > filter out  the garbage more specific /24's from elsewhere.
> You are forgetting that each network provider is free to decide which 
> routes it will carry.  Just because you connect to provider 'a' and 
> provider 'b' does not mean that provider 'c' has to listen to each and 
> every route that 'a' and 'b' carry.
> Now I grant that filtering more specifics of an aggregate does reduce the 
> benefit of multi-homing, but my point is that keeping things the way they 
> are at least gives service providers a way to keep the network running in 
> the event that their routers can't handle the large routing table size. 
> Wouldn't you agree that in that situation it is better to have a reduced 
> benefit to your multi-homing than have an entire backbone shutdown?

If every backbone network filtered out my multihomed /24, how exactly 
would this only be a reduced benefit to my multihoming?  This would be a 
complete waste of time for me.  When packets destined for me hit a 
defaultless router, where do you think the packet is going to go?  Toward 
the ISP that has the large aggregate, which I have lost connectivity with.


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