Cannot change eth0 to 100/Full duplex.

[norbluto]

Hello!

I am trying to change my ethernet card to 100Mbps Full Duplex, so I can get better speed out of my internet connection. The connection is supposed to be 24Mbit/s down. I am using a cablemodem.

Current speed is about 2.0 to 2.5 Mbit/s, so you can imagine I want some more speed. This may be partly due to my ISP, but the first step is to check all settings are OK.

Checking the file var/log/messages, I noticed the eth0 device was set to 10 mbps at half duplex.

I tried to find the best way of changing these settings, and found ethtool. Mii-tool is not installed on my system, and does not exist in apt-get. So i typed into terminal:

sudo ethtool -s eth0 speed 100

and

sudo ethtool -s eth0 duplex full

Checking the file var/log/messages again, I saw this.

+Feb 29 20:39:29 XXXX kernel: [ 598.924000] eth0: link down
+Feb 29 20:39:29 XXXX kernel: [ 598.972000] eth0: link up, 10Mbps, half-duplex, lpa 0x0000
+Feb 29 20:39:36 XXXX kernel: [ 606.056000] eth0: link down
+Feb 29 20:39:36 XXXX kernel: [ 606.112000] eth0: link up, 10Mbps, half-duplex, lpa 0x0000

So, changing the settings this way does not work.

I cannot find any of these settings in K > System Settings > Network Settings

Please help me figure this out!

I already made sure I have DHCP activated.


Kudos



Johan

[norbluto]

Re: Cannot change eth0 to 100/Full duplex.

Hello again.

Here is some new info.

Using ethtool, I tried the following:

sudo ethtool -s eth0 speed 100 duplex full autoneg off

This should change all the relevant the setting all at once. But then I ran ethtool without any options, and got:

Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half
Advertised auto-negotiation: No
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 32
Transceiver: internal
Auto-negotiation: off
Supports Wake-on: pumbg
Wake-on: d
Current message level: 0x00000007 (7)
Link detected: no

Note that advertised link modes is only 10baseT/half.
Also, Link detected is NO.

And after making that change noted above, I get no internet access until I turn it back to 10BaseT/half again. Then the Link detected is YES.

I also tried making that change while also resetting the power on the cable modem=did not work.

Also, when I rebooted, before making any changes in ethtool, Advertised link modes listed all 4 options, including 100baseT/Full.

Any ideas, anyone?

I can only assume this driver works well enough with my card to allow the full options.

Kudos



Johan

[mfburgo]

Re: Cannot change eth0 to 100/Full duplex.

Advertised link modes: 10baseT/Half

This looks like the device your connected to is only providing 10/half

Verify that the device your connecting to can support 100/full.

[mechanism]

Re: Cannot change eth0 to 100/Full duplex.

I decided to check my own Ethernet connection and this is what mine has:

Mar 18 21:22:14 closet kernel: [ 49.583213] lo: Disabled Privacy Extensions
Mar 18 21:22:15 closet kernel: [ 53.111252] eth0: setting half-duplex.

So I have to wonder why it is not set at full duplex automatically? I'm no network wizard or anything and I'm not even sure why I would want full duplex over half duplex BUT if it increases speed then I will take it.

It is not evident to me as to how to change the setting from half to full duplex. Have you discovered how?

Thanks,
Mike

[SlyFerret]

Re: Cannot change eth0 to 100/Full duplex.

What is the device on the other end of the Ethernet cable that you are connecting your computer to?

-SF

[mechanism]

Re: Cannot change eth0 to 100/Full duplex.

For me, it is a Linksys Router WRT54G Version 4 like this one:
http://www.linksys.com/servlet/Satel...=0034939789B04