Not great for passing downstream, but should fill a need internally.
From: "Edvinas Kairys" <edvinas.email@gmail.com>
To: "NANOG Operators' Group" <nanog@nanog.org>
Sent: Monday, October 10, 2022 9:58:45 AM
Subject: any dangers of filtering every /24 on full internet table to preserve FIB space ?
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