I am on a college lan through which one should be able to access the internet. Previously, everything was dandy. I could connect in Linux, surf the web, play Quake, check email etc. Then I switched dorms...

Now, I am having extremely poor internet performance with my desktop computer in linux (laptop is fine). ifconfig shows 7-8% of RX packets have errors. No dropped, overruns or collisions. Ethereal shows local network activity, so I know I'm actually on the lan. When I try to browse the web, sometimes pages partially load but usually links just gets to "Request sent" and the page loading dies. Pinging www.google.com or google.com does not work.

DHCP seems to work ok. During bootup I see the DHCP broadcasts and responses, there's one that says something like "blah missing, assuming". I'm not sure if DHCP is the problem here. I did just re-install Slackware, previous to which DHCP would rarely work (usually "No server response").

In short, I can get on the university LAN, but can not really use the internet.

I have tried 2 different cables, both of which my laptop is able to get on the lan and internet with complete functionality, both in Linux and Windows. Internet and lan works 100% in Windows on my desktop, so I know the nic (netgear FA311) and ethernet jacks are fine. And let me restate, internet and lan in Linux used to work fine... until I switched dorms.

One person told me to try setting my nic to run in half-duplex mode using ifconfig. The man page doesn't seem to tell how to (at least I can't figure it out), and google results in various methods of which only some appear to be correct (I am not sure if any of them are correct actually). Does anyone know how to put an FA311 nic into half-duplex mode?

I am extremely close to just purchasing a new nic (looking at a 3com 905)... but I don't even know if that's the problem... I don't know if it's a software or a hardware problem in fact.... Ugghghr

What the hell do I do?


P.S. if it's unclear, I'm only talking about 2 computers here... one desktop and one laptop, both are dual boots... internet + lan works in everything except linux on the desktop...

I also tried moving my subwoofer away from my computer, because it is not magnetically shielded and I thought it could be interfering with the signal. This wouldn't make much sense since I wasn't having any problems in Windows nor in my previous dorm which had the same subwoofer placement, but it was worth a try I thought. Moving the subwoofer had no effect.

The problems you're describing could well be a duplexing problem. Typically when the duplexing settings are wrong you'll see a ton of errors, but for short bursts of traffic it will be fine.

It's entirely possible that the switch you were previously connected to ran at Full duplex, and the one you're on now is half. However, it's rare that they're 'hard' set like that, unless you're in a datacenter where ALL machines are set to one or the other. Furthermore, Windows will do an 'auto-detect' and pick whichever the switch says it's set at (it's buried in the 'advanced settings' of the network adapator tabs somewhere).

Either way:

mii-tool is what you're looking for. On my system it looks like this :

[root@buffy init.d]# mii-tool
eth0: negotiated 100baseTx-FD, link ok

the FD is the Full Duplex setting. If you want to set it to something different try the -F (force setting) switch. Like so :

[root@buffy init.d]# mii-tool -F 100baseTx-HD
[root@buffy init.d]# mii-tool
eth0: 100 Mbit, half duplex, link ok

You'll see that it's no longer negotiated.

This may or may not help... It's a long shot.

Slick.

All right thanks for replying Slick... trying out mii-tool now...

Running in 100baseT half duplex didn't fix the errors, but running in 10baseT full duplex kind of did. The errors are gone (0 so far), but my connection feels more like a 33.6 modem rather than broadband (download speeds from microsoft.com, which usually maxes out my connection, were 2-3kbps). Using the internet is now possible, it's just at 33.6 speeds...

Just tried 10baseT half duplex... now getting 10-20kbps download speeds.

In Windows, I have gotten upwards of 900kbps... so something must still be wrong.

I am going to try a different Linux distribution and see if that does anything.