[Re: selective auto-aggregation]

Jack Bates jbates at brightok.net
Fri Apr 18 15:24:21 UTC 2003

Joshua Smith wrote:
> i have been told that it is that way for 'backup' purposes (they 
> announce one or two /2[456]s to me with about 15 as prepends, and 
> announce their entire /20, plus all of their longer prefixes, to another
> provider)
> they also told me that it will not be changed...apparently, as routers
> get more powerful and memory gets 'cheaper', they feel that it is not
> their responsibility to help maintain global routing table sizes

That's just beyond me. Since local preference is chosen before AS hop 
count, providers that are setup right allow for easily crafting your 
routing. I run an AS prepend out Sprint with default LP, which allows 
any packet that makes it to their network to come strait to me, but 
anyone that is multi-homed or exterior will probably go out another way. 
I work with communities to make routing symetrical as possible (not 
perfect, but close). Then I shoot out my aggregates via Qwest untouched 
and it's smooth sailing with a backup.

Then again, when dealing with various providers over the years, I've 
gotten some funny looks when I start talking communities and the need 
for symetrical routing.


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