IPFW, KERNEL, sysctl: has no effect changing DUMMYNET.io_fast

KES kes-kes at yandex.ru
Wed Apr 15 18:49:31 UTC 2009


Hi, Freebsd-questions.

This change
sysctl net.inet.ip.dummynet.io_fast=1
has no effect for packet flow, bug man says:
Fast mode allows certain packets to bypass dummynet scheduler if packet flow does not exceed pipe's bandwidth

flow does not exceed pipe limit, but packet flow latency is affected


ipfw pipe 1 config bw 64kbit/s
ipfw add 1 pipe 1 all from any to any

No any trafic except ping:
ping some.lan.machine

with rules above ping is about 8ms, without them <1ms

Does I understand corrent "Fast mode"
when I ping I do flow less than 64Kbit/s so packet must bypass
scheduler and must have latency <1ms?

-- 
С уважением,
 KES                          mailto:kes-kes at yandex.ru



More information about the freebsd-questions mailing list