nanog mailing list archives
Re: BGP to doom us all
From: Iljitsch van Beijnum <iljitsch () muada com>
Date: Sun, 2 Mar 2003 12:33:47 +0100 (CET)
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.
Current thread:
- Who uses RADB? [was BGP to doom us all], (continued)
- Who uses RADB? [was BGP to doom us all] Mark Radabaugh (Mar 01)
- Re: Who uses RADB? [was BGP to doom us all] Neil J. McRae (Mar 01)
- Re: Who uses RADB? [was BGP to doom us all] jlewis (Mar 01)
- RE: Who uses RADB? [was BGP to doom us all] Michael Hallgren (Mar 01)
- Re: Who uses RADB? [was BGP to doom us all] Richard A Steenbergen (Mar 01)
- Re: Who uses RADB? [was BGP to doom us all] Jeffrey Meltzer (Mar 01)
- Who uses RADB? [was BGP to doom us all] Mark Radabaugh (Mar 01)
- Re: BGP to doom us all Andy Dills (Mar 01)
- Re: BGP to doom us all Iljitsch van Beijnum (Mar 02)
- Re: BGP to doom us all Jack Bates (Mar 03)
- Re: BGP to doom us all E.B. Dreger (Mar 03)
- Re: BGP to doom us all Stephane Bortzmeyer (Mar 03)
- Re: BGP to doom us all bmanning (Mar 03)
- Re: BGP to doom us all bmanning (Mar 03)
- Re: BGP to doom us all David Conrad (Mar 03)