Subject: Re: TCP/IP tuning
To: Thomas Miller <firstname.lastname@example.org>
From: Jean-Edouard BABIN <email@example.com>
Date: 02/28/2004 05:08:55
I think that for a 5Mb/sec connection you did not have to tune the system t=
much (exept if you use a very old computer...)
Tuning may be more usefull for Gigabit i think
Also on my kernel (1.6ZH) kern.mbuf.nmbclusters can be changed with sysctl
on 28/02/04 4:16, =AB=A0Thomas Miller=A0=BB <firstname.lastname@example.org> wrote:
> I have a new cable connection which is supposed
> to give me downloads of "up to 5 Mb/sec," and I
> want to tune my -current i386 1.6ZK system to
> take advantage of the new connection.
> I found the following:
> 1. Enabling High Performance Data Transfers
> 2. TCP tuning cookbook
> and the the latter gives specific suggestions
> concerning NetBSD-current:
> Only NetBSD-current (upcoming version 2.0) seems to support really
> fast connections, as there has been much work done on the "zero-copy"
> TCP features of NetBSD lately.
> * Install NetBSD-current
> * Increase IFQ_MAXLEN in /usr/src/sys/net/if.h from 50 (default) to
> something like 1000
> * Enter the line "options NMBCLUSTERS=3D16384" in Your kernel config
> * Recompile and install Your new kernel. Do not try to set the
> values below too high until You have increased NMBCLUSTERS - risk
> of "hanging" the network part of the OS!
> sysctl -w net.inet.tcp.rfc1323=3D1 Activate window scaling and timestamp
> options according to RFC 1323.
> sysctl -w kern.sbmax=3D[wmax] Set maximum size of TCP window.
> sysctl -w net.inet.tcp.recvspace=3D[wstd] Set default size of TCP
> receive window.
> sysctl -w net.inet.tcp.sendspace=3D[wstd] Set default size of TCP
> transmit window.
> sysctl kern.mbuf.nmbclusters View maximum number of mbuf clusters.
> Used for storage of data packets to/from the network interface. Can
> only be set by recompiling Your kernel - see above!
> I was unable to find much about TCP/IP tuning in
> the NetBSD.org web pages or in the mailing list
> archives. So, before I wade in and start changing
> stuff, I though I'd ask here if the above information
> seems correct and complete. Any additional hints
> or tips would be appreciated.
> Thanks! =20
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