Subject: using default route to reach peer

From: "Natale, Jonathan" <[email-masked]>
Date: Thu, 24 Oct 2002 11:37:00 -0400

Folks,

IOS does not allow a BGP peer to be reached via the default route.  This
seems like a good rule to me.  Is this specified in the/a RFC/Draft
somewhere?  Should it be added as a "MAY"?

Thank You,
-Jonathan

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From: Pedro Roque Marques <[email-masked]>
Date: Thu, 24 Oct 2002 11:46:57 -0700 (PDT)

Natale, Jonathan writes:

> Folks, IOS does not allow a BGP peer to be reached via the default
> route.  This seems like a good rule to me.  Is this specified in
> the/a RFC/Draft somewhere?  Should it be added as a "MAY"?

I'm wondering if the document when finished will be published w/ by
Cisco Press... it is starting to seem as if it comes closer to
document and semi-officially sanction the behaviour of a particular
implementation than actually address the underlying technical issues.

The point specifically here is that an implementation must be able to
deal w/ potentially looping routes. i.e. a route which by being
installed in a routing table causes itself to be looping...

A simple minded aproach to the problem above that some implementations
take is to simply deny peering on the default route w/ the logic that
any route installed via that peering session that would be more
specific for the peering session address or nexthop of the default
route would cause all received routes to become looping.

There are implementations however that have a much more complete
aproach to the root problem and have no use for the quick fast hack of
denying peering on default.

The later is imho an implementation specific quirk which is probably
already documented sufficiently on books published under the label of
the equipment vendor in question.

I've no problem w/ any particular vendor or its implementation but
puting down as a standard the solutions of a particular
implementation, which may or may not be the most apropriate, i don't
think the spec is doing a service...

  Pedro.

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From: Curtis Villamizar <[email-masked]>
Date: Tue, 29 Oct 2002 10:27:22 -0500

In message <[email-masked]
> somewhere?  Should it be added as a "MAY"?

I disagree.

[ ..cranky stuff omitted per your request.. ]

We've already clarified the line in the charter that you keep quoting.
We are modifying the draft to reflect current practice only where it
affects interoperability.  We are documenting current practices that
in some way significantly differ from the spec, not ever little Cisco
qwirk.

Nothing should be added or changed for this.

Curtis