There are most definitely a number of organizations that have /24s that are not part of a larger aggregate.
If you don’t have a default route to some router that takes the full table on your behalf, then you will loose connectivity to/from those entities. Owen > On Oct 10, 2022, at 07:58 , Edvinas Kairys <edvinas.em...@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
