Does anyone know what this is?

[xxxxx@home] /ip route cache> print
cache-size: 111
max-cache-size: 32768

3.25 w/ routing-test package.

http://linux-ip.net/html/routing-cache.html

basically a quick lookup table made from the main routing table.

having this size as a configurable value would be a nice addition for using routeros as a router

how long are they cached for? We use BGP and starting to wonder if stale routes are sitting in there.

MT - please include a FLUSH command (pretty please).

500 ms is min delay on ubuntu at least
sysctl net.ipv4.route.gc_min_interval_ms