topic Re: Need to set eth3 to auto auto in Operating System - Linux

Need to set eth3 to auto auto

brian_31 — Mon, 31 Jul 2006 14:19:06 GMT

I need to set my eth3 interface to auto speed and auto duplex..This is the main interface (which the machine uses as ip). my questions are

1. how do i change this? (ethtool?)

2. if i change it then can i be on the network or should i be on the console?

This is on redhat.

Thanks

Brian.

Re: Need to set eth3 to auto auto

Ivan Ferreira — Mon, 31 Jul 2006 14:41:16 GMT

1. how do i change this? (ethtool?)

Yes. If you use some red hat compatible distro, modify /etc/sysconfig/network-scripts/ifcfg-eth3 and add

ETHTOOL_OPTS="autoneg on"

To make it permanent.

2. if i change it then can i be on the network or should i be on the console?

It's better if you do it at the console, the auto-negotiation process may drop you connection. If it does not works properly, you may not have access to your server remotelly again.

Re: Need to set eth3 to auto auto

brian_31 — Mon, 31 Jul 2006 14:45:41 GMT

so..how do i set it to auto speed and auto duplex using ethtool?

Thanks

brian

Re: Need to set eth3 to auto auto

brian_31 — Mon, 31 Jul 2006 14:49:30 GMT

this is what my ifcfg-eth3 looks like

ETHTOOL_OPTS="speed 100 duplex full autoneg off"

Thanks

brian

Re: Need to set eth3 to auto auto

Ivan Ferreira — Mon, 31 Jul 2006 15:13:24 GMT

You can use:

ethtool -s eth3 autoneg on

Then modify your ifcfg-eth3 file and comment the ETHTOOL_OPS line.

Some device have problems with autonegotiation enabled, it's normal to disable the autonegotiation. Why do you want to enable the autonegotiation?

Re: Need to set eth3 to auto auto

brian_31 — Mon, 31 Jul 2006 16:44:42 GMT

this was recommended by the network guys. they said this NIC is connected to gig capable switch.

Thanks

brian

Re: Need to set eth3 to auto auto

Al Licause — Tue, 01 Aug 2006 07:05:33 GMT

You never mentioned the type of network card your using or the driver. These are important.

Most 10/100 or Gigabit cards today use autonegotiation by default so you shouldn't have to set anything. The only time you typically need to set something is if you want something other than the default which will be determined through the negotiation process.

Ethtool is certainly one method of configuring the driver, however, modules.conf or modprobe.conf can also be use. The syntax for setting individual drivers may vary depending on which driver you use.