any dangers of filtering every /24 on full internet table to preserve FIB space ?

Jeff Tantsura jefftant.ietf at
Mon Oct 10 18:18:13 UTC 2022

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; Volta Networks had an implementation of full BGP table compression to about 370K routes with no connectivity loss and  reasonably fast reaction of topology changes/disaggregation needed(it even won some Intel price for innovation), not sure what happened to it (Volta had been acquired by IBM some time ago). To my memory -  IOS-XR allows off box custom best path logic and  re-injection of routes into BGP RIB


> On Oct 10, 2022, at 09:26, William Herrin <bill at> wrote:
> On Mon, Oct 10, 2022 at 8:37 AM Mike Hammett <nanog at> wrote:
>> Feasibility of adding some middleware that culls unneeded routes (existing more specific and aggregate routes pointing to the same next hop), when that table starts to fill?
> This is called "FIB aggregation." It exists and works but is not widely adopted.
> Regards,
> Bill Herrin
> -- 
> For hire.

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