On 9/27/07, Henning Brauer <[EMAIL PROTECTED]> wrote: > > * Tony Sarendal <[EMAIL PROTECTED]> [2007-09-27 10:36]: > > On 9/26/07, Tom Bombadil <[EMAIL PROTECTED]> wrote: > > > > 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 > > Is that per physical or per logical interface ? > > it is a rule of thumb. an approximation. for typical cases. > > > [EMAIL PROTECTED] ifconfig -a | grep ^vlan | wc -l > > 4094 > > that is not a typical case. > you do not wanna set your ifqlen to 1048064 :) > > the highest qlen I have is somewhere around 2500. > where the high watermark is... I cannot really say. I'd be careful > going far higher than the above.
I meant if the input queue length was per physical or logical interface. There are places where I actually need boxes with more than 1k vlan subinterfaces. If net.inet.ip.ifq.maxlen is per logical interface I see some potentional issues under load. /Tony
