Found out some big information. I wrote two test scripts, one
polls the routing table of 1000 ip's, single threaded. The other
polls the 1000 ip's as 100 threads. It does nothing except get the
routing table -- it's the same polling code. The threaded version
blows up on memory, the single threaded stays steady. So something
about threads really hornkles Net::SNMP's nose. I contacted the
author and he seems willing to look into it.
But man, atleast now I know *where* the leak is coming from. O_O