Date: Sun, 17 Oct 1999 23:48:32 +0100 From: Richard Morte <ric@sinclairassoc.force9.co.uk> To: "Daniel T. Chen" <crimsun@email.unc.edu> Cc: Dan Nelson <dnelson@emsphone.com>, Ian J Greely <ian@tirnanog.org>, "freebsd-questions@FreeBSD.ORG" <freebsd-questions@FreeBSD.ORG>, Mark Einreinhof <montana1@home.com> Subject: Re: Full or Half Duplex NICs Message-ID: <380A5240.BBDDA756@sinclairassoc.force9.co.uk> References: <Pine.A41.3.95L.991016232606.152156B-100000@login3.isis.unc.edu>
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Dear All, Thank you for replying. I am away till Wednesday, so will not find out immediately from Netgear whether the hub supports full duplex. However, since it is a hub and not a switch, Dan Nelson's advice that hubs do not support full duplex may yet prevail (the reason why the docs that came with the hub never mention full/half duplex?). The issue of full /half duplex only came to light when I noticed that the windows clients had defaulted to full duplex, yet those on both the FreeBSD boxes defaulted to half duplex. So my question is more about optimisation than repairing anything that's not strictly broken. With the ifconfig command I could fiddle with the settings, but I have no way of consistently measuring network performance, collisions, etc. All I can tell is that there are very few collision instances on the hub (leds on the front panel) during file transfers, internet access, etc, so I guess the current configuration is OK. I recently replaced a 3com 3c905b (10M/s) with the FA310TX: with the 3c905 the number of collissions seemed horrendous even during small file transfers, so the network has improved considerably since the change. No need to reply. I have enough info now to go on. Thanks again, Ric "Daniel T. Chen" wrote: > > On Sat, 16 Oct 1999, Richard Morte wrote: > > > I have a network configured with the Netgear FA310TX ethernet cards and > > Netgear 8 port hub. Cards are 10/100 and hub is 10/100 autosensing. On > > bootup both FreeBSD machines default to: > > > > media: 100BaseTX (half-duplex) > > > > Would there be any advantage in running the entire network at full > > duplex? If so, how do I specify this in ifconfig? > > Ric, > Forgive me if I'm wrong, but just because your NICs and your hub > are 10/100 autosensing does not mean that full-duplex operation is > automatically supported. Upon boot, probing of eth0 should return whether > the entire network is *capable* of full-duplex operation, though it *is* > possible to force the hardware into such a mode. It is generally not > recommended that you do so since your hub may not support full-duplex > operation even though it is 10/100 Base-TX autosensing. > A `man ifconfig` should give you the command-line switch(es) you > need to force your NIC into full-duplex operation. > Hope I'm not too far off-base here. ;-) > > -d > > --- > Daniel T. Chen > daniel_chen@unc.edu To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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