In article <10322.05320.15507@avi.netaxs.com> The Great Sean wrote: : 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
On Sun, 2 Mar 2003, Avi Freedman wrote:
In article <10322.05320.15507@avi.netaxs.com> The Great Sean wrote: ^^^^^^^^^^^^^^
: 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.
From: "Avi Freedman" <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
JB> Date: Mon, 3 Mar 2003 09:45:37 -0600 JB> From: Jack Bates JB> Personally, I think ARIN handling routing information is an JB> 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 -- Brotsman & Dreger, Inc. - EverQuick Internet Division Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 (785) 865-5885 Lawrence and [inter]national Phone: +1 (316) 794-8922 Wichita ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Date: Mon, 21 May 2001 11:23:58 +0000 (GMT) From: A Trap <blacklist@brics.com> To: blacklist@brics.com Subject: Please ignore this portion of my mail signature. These last few lines are a trap for address-harvesting spambots. Do NOT send mail to <blacklist@brics.com>, or you are likely to be blocked.
participants (4)
-
Avi Freedman -
E.B. Dreger -
Iljitsch van Beijnum -
Jack Bates