nanog mailing list archives
Re: any dangers of filtering every /24 on full internet table to preserve FIB space ?
From: Ca By <cb.list6 () gmail com>
Date: Mon, 10 Oct 2022 08:08:38 -0700
On Mon, Oct 10, 2022 at 7:59 AM Edvinas Kairys <edvinas.email () gmail com> wrote:
Hello, We're considering to buy some Cisco boxes - NCS-55A1-24H. That box has 24x100G, but only 2.2mln route (FIB) memory entries. In a near future it will be not enough - so we're thinking to deny all /24s to save the memory. What do you think about that approach - I know it could provide some misbehavior. But theoretically every filtered /24 could be routed via smaller prefix /23 /22 /21 or etc. But of course it could be a situation when denied /24 will not be covered by any smaller prefix. What do you think about this approach ? Also maybe you know - some advices for edge routers that have at least 8x100G interfaces and "good" memory for prefix count ? Thanks
Sounds good to me. Especially , if you are prioritizing ipv6 routes in your fib What is your use case ? Selling transit bgp might be tricky since you will be not sending specifics to your downstreams. If you are edge network like me, taking a default from your upstream solves all problems and you can filter and TE as you wish.
Current thread:
- any dangers of filtering every /24 on full internet table to preserve FIB space ? Edvinas Kairys (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Ca By (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Stephane Bortzmeyer (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Stephane Bortzmeyer (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Brie (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Randy Bush (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? John Gilmore (Oct 10)
- RE: any dangers of filtering every /24 on full internet table to preserve FIB space ? Tobias Fiebig (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? Geoff Huston (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? richey goldberg (Oct 10)
- Re: any dangers of filtering every /24 on full internet table to preserve FIB space ? David Bass (Oct 10)