How do you check the network speed of a Redhat machine.

[Ed Wilts]

On Mon, Feb 07, 2005 at 11:40:16AM +0000, Andrew.Bridgeman at corusgroup.com wrote:
> I need to check to see if my Redhat machines are running on 100 Half/Full
> or 1000 Half/Full, can someone tell me how to check this from the command
> line. I have tried ifconfig but it does not tell you the speed. Any help is
> much appreciated.

ethtool is the suggested tool these days.  Here's an example output
showing my GigE interface running at 100mbps Full.

[root at pe400 ~]# ethtool eth0
Settings for eth0:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised auto-negotiation: Yes
        Speed: 100Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: umbg
        Wake-on: g
        Current message level: 0x00000007 (7)
        Link detected: yes

If you need to change the parameters, add an entry named ETHTOOL_OPTS in
/etc/sysconfig/network-scripts/ifcfg-eth0 (or whatever your adapter name
is).  The arguments will be passed directly to ethtool when the
interface is up'ed.

-- 
Ed Wilts, RHCE
Mounds View, MN, USA
mailto:ewilts at ewilts.org
Member #1, Red Hat Community Ambassador Program