> net.inet.ip.ifq.maxlen defines how many packets can be queued in the IP > input queue before further packets are dropped. Packets comming from the > network card are first put into this queue and the actuall IP packet > processing is done later. Gigabit cards with interrupt mitigation may spit > out many packets per interrupt plus heavy use of pf can slowdown the > packet forwarding. So it is possible that a heavy burst of packets is > overflowing this queue. On the other hand you do not want to use a too big > number because this has negative effects on the system (livelock etc). > 256 seems to be a better default then the 50 but additional tweaking may > allow you to process a few packets more.
Thanks Claudio... In the link that Stuart posted here, Henning mentions 256 times the number of interfaces: http://archive.openbsd.nu/?ml=openbsd-tech&a=2006-10&t=2474666 I'll try both and see. Thanks you and Stuart for the hints.
