Stuff to do

Routing socket filters
many tools in userland are only interested in interface state changes
bgpd produces an insane amount of messages
dhclient uses 10-30% CPU time if bgpd couples its FIB

Profile and optimise network stack
Is netisr the bottleneck?

Replace patricia tree with a more performing alternative
original patricia tree was developed for a VAX
current CPU work differently, memory access is expensive