Verio Decides what parts of the internet to drop

Alex Rubenstein alex at nac.net
Thu Dec 2 23:34:47 UTC 1999


On Thu, 2 Dec 1999, Jared Mauch wrote:

> 	Your pager didn't go off when the routing table had 100k prefixes
> in it, I take it.
> 
> 	This is a Good Thing(tm).

Au contriar, monfrair (sp?). I was among the first to call Vinnie.


> > I believe that if I have a customer who is multihomed between me and
> > another provider, his punch-throughs to the non-address-space-providing
> > provider should be heard. It's called 'global routability.'
> 
> 	The people who "purchased" this space, didn't realize that such
> routing policies exist, and it is not the problem of someone trying to reach
> them, it's the problem of the person who is using address space that
> was not originally assigned to them.

You misinterpreted.

Multihomed customer gets a /24 of my announced /16. He's announcing that
/24 to his other provider; since it is more specific the other provider
will always win (BGP 101). So, for it to work, I need to allow a punch
through of a /24 to my peers. And for it to _really_ work, people would
have to listen to the /24 from both us and the other provider to our
multihomed customer.

> > There are ways to get around this (as-path filtering, maximum-paths, etc)
> > that aren't as nazi as one would hope, but will prevent stupidity and
> > provide sanity checking.
> 
> 	Maximum paths deals primarily with ibgp

Well, thats patently wrong. I don't know how else to respond to this.


> 	as-path filtering?  How will this help?

It will prevent redistribution of a person who announces * to you. It
won't fix everything (including the 7007 debacle, but thats a whole
another story), but it will fix most fsck-ups.


> 	Oh yeah, I'll as-path filter my peers, and then have even
> more reacability issues.

Tell Sprint, Agis, and others. Unless they changed since my last dealing
with them.


> > But unfortunate. Will they announce a customer-announced /24?
> 
> 	Yes.
> 
> 	They can't guarentee that peers will listen to it though.

Well, it's a start.



> Jared Mauch  | pgp key available via finger from jared at puck.nether.net
> clue++;      | http://puck.nether.net/~jared/  My statements are only mine.
> END OF LINE  |





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