How to find out the speed of LAN interface

[Mark Grant]

Are those two extra cards actually configured?

Doesn't look like it at first glance.

[Mark Grant · Accepted solution]

Actually Kapil, mii-tool does seem to be showing you eth3.

Remember we start at eth0 so the output for eth2 is your third card and it says that it is 100baseTx-FD. eth3 should be your fourth card and it just says "no link" which I would suspect means it isn't plugged into anything.

[Bill Thorsteinson]

You can specify which device on the command line
such as

mii-tool -v eth0

If it report operation not supported, then
either the card does not support MII opteration,
or the driver has been configured to single
speed/duplex at initialiation. Check the
/etc/modules.conf file to see which parameters
have been used.

I have network admins who insist on configuring
Cisco routers at 100/Full. However, the MII
announcement in this case is 100/Half, so we
initialize the cards to 100/Full.

If the card reinitializes, mii-tool starts
telling us what the settings are and we
have a duplex mismatch.