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.