Duplex: 'Auto' and '10 Half'

NICK · Post by **NICK** » Sat Feb 23, 2002 1:25 pm

I took some tweak advice from Lobo and he said to change the duplex to half. It worked for a while but then it said my network cable is unplugged and so I called tech nd they said i should replace my NIC card. So wo/ internet, i fiddled around my settings and then it reminded me my network cable was unplugged. I closed the warning and tried my IE again and now it works

sooo...what happened there? and im not blaming lobo

btw ive got Aopen Realtek RTL8139 family pic fast ethernet NIC card.

mnosteele52 · Post by **mnosteele52** » Sat Feb 23, 2002 2:13 pm

For optimum performance this should be set to half duplex as Lobo suggested. What did you change it to that now allows it to work?

Lee_Nover · Post by **Lee_Nover** » Sat Feb 23, 2002 2:29 pm

When you change if from auto to half, or change anything on the settings, Windows drops the connection to the NIC and then re-instates it with your new settings. Sometimes it may lose it again, and a reboot, or exiting IE and then re-opening would fix it. If you are okay now, don't worry about it.

NICK · Post by **NICK** » Sat Feb 23, 2002 3:54 pm

i put it from half to auto.

Lee_Nover · Post by **Lee_Nover** » Sat Feb 23, 2002 8:47 pm

and he said to change the duplex to half

Oh, I thought you changed it from auto to half, as per Lobo. You are now confusing me.

Nefarious · Post by **Nefarious** » Sat Feb 23, 2002 9:05 pm

If you were running on a network with a switch thats 10/100. Instead of having it set at Auto would you set it to 100TX FULL? Since the Switch is full duplex? Remind you this is ICS and Im on WinXP. Or should I just do 10T Half because thats what the Modem has? Also if I do set it to 10T that means I then make everything on my network 10Mbps Transfer. **** what to do.

Lobo · Post by **Lobo** » Mon Feb 25, 2002 3:25 pm

It has been verified by experiment that certain auto-negotiating ethernet cards (both in PCs and in Macs), when connected to certain models of cable modem, sense the ethernet duplex setting incorrectly. Such a cable modem has ethernet hardware which is capable of operating only in half-duplex mode, at 10 Mbps, yet some auto-negotiating ethernet cards sense it as full-duplex. If an auto-negotiation card incorrectly starts operating in full-duplex mode, there can be collisions between ethernet packets being transmitted in both directions at the same time, leading to packet loss, and repeated re-transmissions. There is no visible evidence of this apart from poor performance. This problem can be avoided by manually configuring your ethernet card to be 10 Mbps half-duplex. No ill-effects will transpire from doing this, even when it is not necessary. The exact wording of the setting changes required varies from one manufacturer to another, so the instructions below are necessarily rather broadly defined.

To make this change under Win98/ME, follow these steps:

Open Control Panel.
Double-click Network.
From the scrollable list, select your Ethernet adapter (rather than any dial-up) with a green icon.
Click the button Properties.
Click the tab Advanced to bring it to the front:
In the Property box, the property name to be selected varies according to model of ethernet card. Examples are: Network Link Selection, Media Type, Connection Type, Duplex Mode, or any similarly-named property which can have Values looking like Auto-Negotiation, or 10BT, or 10BaseT.
In the Value box, select a value which either (a) explicitly says half-duplex or semi-duplex, or (b) at least does not say full-duplex [e.g. 10BaseT on its own is OK]. If there is a choice between 10 and 100 with half-duplex, choose the 10. Do not choose 10Base5, 10Base2, or AUI.
Click OK to exit the Adapter settings.
Click OK all the way out - you might need to restart.
To make this change under Windows 2000 or XP, follow these steps:

Open Control Panel.
Double-click Network and Dial-up Connections.
Identify the icon for your cable modem connection: usually Local Area Connection.
Right-click that icon and select Properties.
Under the ethernet adapter icon, click the button Configure.
Click the tab Advanced to bring it to the front:
In the Property box, the property name to be selected varies according to model of ethernet card. Examples are: Network Link Selection, Media Type, Connection Type, Duplex Mode, or any similarly-named property which can have Values looking like Auto-Negotiation, or 10BT, or 10BaseT.
In the Value box, select a value which either (a) explicitly says half-duplex or semi-duplex, or (b) at least does not say full-duplex [e.g. 10BaseT on its own is OK]. If there is a choice between 10 and 100 with half-duplex, choose the 10. Do not choose 10Base5, 10Base2, or AUI.
Click OK to exit the Adapter settings.
Click OK to exit the Connection properties

NICK · Post by **NICK** » Mon Feb 25, 2002 7:11 pm

ThANKS LOBO!!!!

You received 2619537 bytes in 16.644 seconds. Throughput is 1229 Kbps.

and

Loaded 620871 Bytes in 3.0611250400543 seconds
1622.6Kbps is your thruput