: I'll be stupid, and ask some questions I've always wondered about.
: Why should routes learned by eBGP have a higher priority than iBGP?
Love to know myself. Took me a few years to figure out why the strange
iBGP redistribution rules (because barring something like confeds or
RRs, there's no loop detection method in iBGP w/o it...)
: Why should BGP implementations flap all good routes when they see a single
: bad route packet?
Sorry if this isn't adding enough signal, but Amen! However, there's
some disagreement historically about this. I am in the camp who thinks
the danger is higher from being able to trigger massive #s of session
drops cyclically, but some argue that it's worse to continue talking
to someone who may be spewing badness that you only see as syntax error,
but some packets may have OK syntax and bad contents.
This may be doomed to the neverending debate category, but I feel fairly
strongly that I'd at least like a knob that makes NOTIFY not kill
sessions (but you'd probably need to twist it it at both ends of the
session).
: Why don't SWIP forms include Origin-AS?
Ahem. Origin-AS(s) - plural. Agreed - mildly. Of course, SWIP isn't
updated when delegation info changes, so origin AS(s) would get just as
stale as contact info.
Avi
^^^^^^^^^^^^^^
: I'll be stupid, and ask some questions I've always wondered about.
: Why should routes learned by eBGP have a higher priority than iBGP?
Love to know myself.
Consider the situation where two routers have an external path to a
destination, but they both prefer the path over the other. This can
create routing loops and BGP instability as routers keep revoking and
reannouncing their external routes over iBGP.
However, the "external first" rule is a relatively weak one, as it only
kicks in when the BGP route selection algorithm can't decide which route
is better. If you use the local preference, AS path or multi-exit
discriminator to prefer one of the BGP routes, all routers will use this
one, regardless of whether they learn it over eBGP or iBGP.
<snip>
: Why don't SWIP forms include Origin-AS?
Ahem. Origin-AS(s) - plural. Agreed - mildly. Of course, SWIP isn't
updated when delegation info changes, so origin AS(s) would get just as
stale as contact info.
If networks are filtering based on SWIP information, it will get updated.
Personally, I think ARIN handling routing information is an excellent idea.
It has to be separate from SWIP though, as rwhois servers don't issue SWIP.
On the other hand, if ARIN authoritates the block to the AS and then a
lookup to the AS's server provides any subdelegations, that might work.
-Jack
Date: Mon, 3 Mar 2003 09:45:37 -0600
From: Jack Bates
Personally, I think ARIN handling routing information is an
excellent idea. It has to be separate from SWIP though, as
Uhhhh.... it's nice to be able to change routing information in a
timely fashion without needing intensive therapy afterward. The
idea isn't inherently bad, but I'd not want the current ARIN
acting as a route registry.
Eddy