Hi all, I'm seeing something strange here... I have a freebsd box running iperf (4.6-RELEASE-p1, iperf 1.6.2 with pthreads patches). When attempting to use a 1MB tcp window, the box won't put more than 256kB in flight after the first connection to a given host.
I seem to remember hearing/reading/whatever that freebsd keeps track
of congestion stats for a route in the kernel routing table and
primes the congestion window for new sockets to the same destination
with the previous values (thus eliminating a congestion avoidance
cycle on each new socket). High-bandwidth connections between the
hosts in question (the other is a linux box of indeterminate recent
version) do hit congestion the first time.
However, in this particular case (since this is a test machine that
we use to diagnose network problems) I'd like to be able to turn it
off. I didn't see anything in sysctl that looked obvious, but I'm
perfectly willing to believe I missed it.
So, can this be turned off? Also, what is the timeout on this data
in the kernel?
Thanks!
--eli
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