[sandman]

So I am back at school now, and my problem persists: My ethernet card is auto-selecting half-duplex, when I need to be running at full-duplex to get full bandwidth.

I can successfully force the card to full-duplex, but then I can't get an internet connection. Network Utility shows that packets are being sent and received and that there are no errors. So now I am asking for help troubleshooting my ethernet settings at full-duplex. I know my settings for speed/duplex are correct (10baseT/UTP, full-duplex), now I need to find whats blocking my web connection.

Thanks in advance.

[Powaqqatsi]

Your modem doesn't support full-duplex that's your problem

[OptimusG4]

BroadbandOptimizer. Try it and see if it works for you.

[sandman]

Originally posted by Powaqqatsi:
Your modem doesn't support full-duplex that's your problem

Its not my modem, its my ethernet card, and yes my ethernet card supports full-duplex, as it runs full duplex just fine on my cable modem at home.

Originally posted by OptimusG4:
BroadbandOptimizer. Try it and see if it works for you.

I am current running it and it doesn't solve the problem.

[iNub]

Maybe your switch at the school isn't full duplex. I've never heard of one that isn't, but that doesn't mean they didn't cheap out and buy some crap switch.

[sandman]

Originally posted by iNub:
Maybe your switch at the school isn't full duplex. I've never heard of one that isn't, but that doesn't mean they didn't cheap out and buy some crap switch.

It is full-duplex, I've already determined that the switch has to be at 10baseT/UTP, full-duplex to get full bandwidth. I can get my ethernet card to use these settings, but for some reason I'm not getting a web connection. What tests might I be able to run to see whats going on?

[sandman]

Originally posted by sandman:
It is full-duplex, I've already determined that the switch has to be at 10baseT/UTP, full-duplex to get full bandwidth. I can get my ethernet card to use these settings, but for some reason I'm not getting a web connection. What tests might I be able to run to see whats going on?

Anyone?

[LeeG]

Shouldn't this be discussed in the networking forum...??

[proton]

OK, so what can you do? Run the commands in bold in the Terminal to see what happens. You'll probably need the BSD Subsystem to be installed on your machine for them to work.

Can you ping a known good host on the network? Try and ping a host that is known to be on by it's IP address:

ping 123.45.67.89

If that suceeds, can you establish a successful TCP connection with a service on that machine. For example, if the machine is running a web server, you could try and connect to the webserver:

telnet 123.45.67.89 80 where 80 is the port that the service is running on. If you connect successfully, you should receive something like this:

Code:
Trying 123.45.67.89...
Connected to 123.45.67.89.
Escape character is '^]'.

If that does work, and you're connecting to a webserver try and request the main page from it, type the following:

Code:
GET / HTTP/1.1
Host: 123.45.67.89

Note that you need to enter two new lines after the Host: line. You should receive some HTTP headers back, followed by the contents of the top level document of that server.

Tell us how you go and we'll see what else we can do.

- proton

[wadesworld]

Sandman,

It's possible the switch implements full-duplex in a way that is not compatible with your machine. This usually occurs with older switches.

I was playing with an older switch the other day at home. I turned on full-duplex on my Mac and the switch, and began taking tons of errors on the switch port. The same errors occurred with my PC laptop, but did not occur with my firewall.

So, I'm forced to leave both my PC and Mac at 10 Megabits/half duplex with this particular switch, even though some other devices work.

I'd have the networking staff watch the port for errors when you have the Mac forced to full-duplex. I'll bet they find some.

If this is the problem, a possible fix for the problem would be to get an inexpensive switch (such as a Linksys) and put it between you and the campus switch. Hopefully, it will play nice with the campus switch at full-duplex, and also with your Mac. A side benefit is that file transfers between your Mac and your roommates PC would be extremely fast, since they'd be connected at at least 100 Mbps full-duplex through this "in-room" switch.

Wade