10 Aug
2021
10 Aug
'21
5:29 a.m.
Sabri Berisha wrote:
Just for fun, I did the math. A total of 16,777,216 /24s fit in 32 bits. Take away all the reserved space as per IANA (this is 1,266,696 /24s, see below),
240.0.0.0/4 1048576
I think we should also take away multicast addresses of
224.0.0.0/4 1048576
because multicast route can not be aggregated and must be treated as /32. Anyway,
The largest FIB table I have seen (hi Jim!) was 3,563,546 routes in hardware. This was in a lab environment, of course.
for /24, these days, having 16M entry SRAM (simple one, not TCAM) is trivially easy. Masataka Ohta