Subject: Re: Weird TCP/IP behaviour
To: Manuel Bouyer <bouyer@antioche.lip6.fr>
From: Paul Mather <paul@gromit.dlib.vt.edu>
List: port-alpha
Date: 11/26/2001 15:37:19
On Mon, 26 Nov 2001, Manuel Bouyer wrote:

=> On Mon, Nov 26, 2001 at 10:20:37AM -0500, Paul Mather wrote:
=> > I have a DEC 3000/300 running NetBSD-current completely rebuilt
=> > (kernel+userland) as of about a week ago.  I noticed some really weird
=> > TCP/IP behaviour that maybe someone can shed some light upon.
=> >
=> > For some reason, I get *terrible* speeds when FTPing *to* an AIX 4.3.3
=> > box.  The weird thing is that I get normal speeds when FTPing *from*
=> > that same AIX box.  Actually, it's more likely it involves FTPing *to* a
=> > particular subnet, as the same behaviour manifests when FTPing *to* an
=> > OpenBSD machine on the same subnet as the AIX machine (but not *from*
=> > that machine).
=>
=> Are you using 10baseT ? If so check the duplex settings on both end of
=> the cable.

I am using 10baseT.  I'm not sure how to check the duplex settings.  On
my end, I think the 3000/300 only supports half-duplex.  Ifconfig says
the media is set to "Ethernet manual".  The other end of the cable goes
to a switch in the building, configured to who knows what, but I suspect
it auto-detects 10/100baseT and duplex settings.

AFAIK, the network hardware in the 3000/300 is the same as the 3000/500,
and both machines are on the same subnet, configured to use the same
default gateway, yet only the 3000/300 running NetBSD gives problems.
Also, wouldn't a wrong duplex setting affect speeds in both directions,
and to the same subnet, too?  The problem I am experiencing is only when
FTPing *to* a different subnet from the 3000/300 (things are okay when
FTPing *from* a different subnet from the 3000/300).

Cheers,

Paul.

e-mail: paul@gromit.dlib.vt.edu

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