Subject: Networking speed
To: None <>
From: Mark White <>
List: tech-net
Date: 09/30/2004 12:34:36
I'm having fairly regular problems with transfer speed, and
wondered if anybody could suggest anything I could try.

I have a small network with two NetBSD/i386 installs (a
Duron with 2.0_BETA "mirkwood" and an elderly Pentium with
1.6 doing firewall duties "lorien"), plus a few macs.  Both
i386s have Sundance ST-201 NICs, all on a Netgear FS108.

On a good day I see 10MB/s plus with scp or ftp; but
sometimes sustained rates drop to under 100kB/s.  mirkwood
is always involved; often it's only for transfers in one
direction.  Watching the switch traffic lights, the problem
seems to involve brief bursts of activity follow by gaps (a
second or more).  Between other machines transfers are fast
and the lights flicker continuously.  I've seen problems
between the two NetBSD machines, but as I'm writing this
it's transfers to mirkwood from one of the macs which crawl.

I don't think it's:
  - The hardware (NICs & switch upgraded recently, and I've
    had same problem intermittently with the old and new ones)
  - A duplex mismatch (they're all on full, and I've tried
    various things, including manually setting all to half).
  - Particular protocol problem (happens with ftp and scp)
  - The fault of NetBSD 2.0_BETA (it's been happening for a
    while, including on 1.6 before I upgraded)

Although the problems are intermittent, it doesn't help to
reboot either machine, or to reset the switch.

I've seen a few similar problems reported on the mailing
lists, but the only suggested solution is duplex probs.  I
did have something similar on a different machine and
network a while back, and somebody suggeted NetBSD's CWM;
turning it off did the trick.  But that's not it this time.

One more symptom: although the duplex settings don't affect
things, if I set the media to 10baseT at one [either] end of
the connection, I do get full 10Mbps speed (ie nearly 1MB/s).

Any thoughts?  At all?  (Please Cc me; I'm not on tech-net).

Mark <><