Find the speed of your Ethernet card in Linux

[Md. Minhaz Khan]

Dear All,

When i run "mii-tool -v eth0" its shows me
"eth0: negotiated 100baseTx-FD, link ok" that is speed of Ethernet card is 100Mb/s, Full Duplex but when i run "ethtool eth0" its shows me speed=1000Mb/s.

I have attached both "mii-tool" & "ethtool" command output. Please check it.

Please which information is correct??

Note:
OS= RHEL AS release 4 (Nahant Update 5) 64 bit
Environment = ESX VMWARE

Thanks
Minhaz

[Matti_Kurkela · Accepted solution]

The "mii-tool" is obsolete. It was designed for 100 Mb/s cards only, and cannot show any speeds faster than that.

When the gigabit NICs were introduced, the developers noticed the problem and built the newer ethtool API that is designed to allow even higher speeds in the future. Unfortunately, this required users to switch from mii-tool to ethtool.

Some old 100 Mb/s NIC drivers still don't have ethtool API support in them. For those old drivers, the mii-tool is still included in RHEL 4.

MK

[Md. Minhaz Khan]

Daer MK,

Thanks a lot for your information. Can you please see my another thread for Redhat Cluster (Quorm Disk Heuristic)

Thanks
Minhaz