BGP Question - how do work around pigheaded ISPs

Stephen Sprunk ssprunk at cisco.com
Mon Feb 12 07:37:48 UTC 2001


Thus spake "Stephen Griffin" <stephen.griffin at rcn.com>
> These companies, conversely, don't care about the costs that _every
> other BGP speaker in the default-free zone_ has to incur as a direct
> result of their actions. Who is expected to bear the cost, the one or
> the many?

There is a cost associated with each AS connecting to the Net; if you
want your customers to have access to every AS, you will accept all
_reasonable_ advertisements.  One prefix per AS is certainly more
reasonable than common practice -- just look at The Cidr Report.

> That ISP is less likely to have any successful litigation against it
> through sticking to their policy. Converse to your argument, ISP
> helpdesks could point their customers to call the company's helpdesk
> for failure to properly announce their address space.

Define "properly."

The companies in question are different legal entities, operating in
different countries, with no common ISPs, and no direction connection to
each other.  By definition, they are two different AS's with two
different prefixes and two different routing policies.  There is no
valid way for these two companies to collectively announce a single
route.

> As the routing table size continues to increase, the number of
entities
> who filter will increase, especially those who could better spend the
> upgrade costs on direct revenue generation.

History has shown the reverse to be true.

> While it may never happen in my lifetime, full-scale IPv6 deployment
> will undoubtedly make filtering an absolute requirement.

Anyone who doesn't already filter extensively is an AS7007 waiting to
happen.

> Now we've moved from the hypothetical to the nasty. I think the
> community is better served with an open and frank discussion on
> prefix filters, what is reasonable, and technical solutions to the
issues
> or non-issues cited.

Citing "technical reasons" for excessive filtering but allowing
exceptions for your own customers is clearly hypocritical.  It's either
a technical problem or it's not.  Consistency is the issue, not the
theoretical limits of the routing system.

S





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