On 10/10/22 16:58, Edvinas Kairys 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.
I wouldn't bank on that.
I am confident I have seen /24's with no covering route, more so for PI
space from RIR's that may only be able to allocate a /24 and nothing
shorter.
It would be one heck of an experiment, though :-).
Mark.
