nanog mailing list archives
Re: any dangers of filtering every /24 on full internet table to preserve FIB space ?
From: William Herrin <bill () herrin us>
Date: Mon, 10 Oct 2022 11:37:20 -0700
On Mon, Oct 10, 2022 at 11:18 AM Jeff Tantsura <jefftant.ietf () gmail com> wrote:
There has been a number of efforts to implement FIB (actually BGP RIB) compression. There’s a white paper from MS research; I recall Spotify talking of running off-box BGP compression SW and re-injecting summarized BGP RIB;
Hi Jeff, Actually, I was talking about FIB aggregation/compression where you take a full BGP RIB but optimize the prefixes placed in the local FIB so that you don't need a FIB entry for every RIB entry. Solid FIB compression can give you a 50% savings in FIB entries without altering the next hop selected for any reachable destination IP address. Costs main processor time computing the FIB from the RIB of course, which can be challenging in a large change event (e.g. a link loss). Excepting source aggregation and terminal default routes, RIB compression and reinjection is dangerous on multiple levels from accidental leaks to connectivity loss and (in my opinion) should not be done. Regards, Bill Herrin -- For hire. https://bill.herrin.us/resume/
Current thread:
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ?, (continued)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Nick Suan via NANOG (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Jim Troutman (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? William Herrin (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Mike Hammett (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Elmar K. Bins (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Mike Hammett (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? William Herrin (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Jeff Tantsura (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? William Herrin (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Elmar K. Bins (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Mark Tinka (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Matthew Petach (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Ryan Rawdon (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Jeff Tantsura (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Mark Tinka (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? William Herrin (Oct 11)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Matthew Petach (Oct 11)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? William Herrin (Oct 11)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Richard Golodner (Oct 11)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Matthew Petach (Oct 11)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Matthew Petach (Oct 10)