nanog mailing list archives
Re: BGP peering strategies for smaller routers
From: lincoln dale <ltd () interlink com au>
Date: Mon, 2 May 2016 13:27:40 -0700
You have to keep in mind there are two pools of memory on the router.
There's actually three. 1. Prefix (path) via BGP: "show ip bgp <prefix>". BGP will select the 'best' BGP path (can be multiple if ECMP) and send that through to the RIB. 2. RIB. "show ip route <prefix>". routing table will show the path chosen - and if there are backup paths etc, but may be recursive, e.g. prefix a.b.c.d points at e.f.g.h which in turn points at i.j.k.l etc. 3. FIB. basically fully resolved prefixes. What you otherwise say is correct - you could have N transit providers at (1) providing lotsOfPaths x N providers which ultimately resolve to lotsOfRoutes with up to N next-hops. Much design effort goes into the routing stack to efficiently store lotsOfPaths. Can't speak for what an ASR1K does but suggest the OP talk to Cisco. cheers, lincoln.
Current thread:
- BGP peering strategies for smaller routers Mike (May 02)
- Re: BGP peering strategies for smaller routers James Milko (May 02)
- Re: BGP peering strategies for smaller routers lincoln dale (May 02)
- Re: BGP peering strategies for smaller routers Mark Tinka (May 02)
- Re: BGP peering strategies for smaller routers Bob Evans (May 02)
- RE: BGP peering strategies for smaller routers Gustav Ulander (May 02)
- RE: BGP peering strategies for smaller routers Tony Wicks (May 02)
- Re: BGP peering strategies for smaller routers Blake Hudson (May 02)
- Re: BGP peering strategies for smaller routers Richard Hicks (May 02)
- Re: BGP peering strategies for smaller routers Mark Tinka (May 02)
- Re: BGP peering strategies for smaller routers William Herrin (May 03)
- RE: BGP peering strategies for smaller routers Eric Sabotta (May 03)
- Re: BGP peering strategies for smaller routers Mike (May 02)
(Thread continues...)
- Re: BGP peering strategies for smaller routers James Milko (May 02)