[CentOS] network interface cards with gig support

Tue May 8 16:10:28 UTC 2007
Greg Bailey <gbailey at lxpro.com>

Gregg wrote:
> anyone know how to force network cards talk at gig speeds when all it
> wants to do is establish a connection at 100mbits
>
> root at host1 [/backup/cpbackup/daily]# mii-tool
> eth0: negotiated 100baseTx-FD, link ok
> eth1: negotiated 100baseTx-FD flow-control, link ok
>
>
>   
One of mii-tool's limitations is that it doesn't report gig speeds 
correctly.
 From the man page:

NOTE
       This program is obsolete. Valid media are only 100baseT4, 
100baseTx-FD,100baseTx-HD, 10baseT-FD and 10baseT-HD ethernet cards. For 
replacement check eth-tool.

Using ethtool:

[root at el4-node1 ~]# ethtool eth0
Settings for eth0:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Half 1000baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Half 1000baseT/Full
        Advertised auto-negotiation: Yes
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        Current message level: 0x000000ff (255)
        Link detected: yes

-Greg