Check if network cable is plugged in and working correctly

mii-tool eth0
with 'mii-tool -w eth0' you can watch the interface for changes of the link status
Sample Output
eth0: negotiated 100baseTx-FD, link ok

By: flart
2009-06-24 08:43:55

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    for i in `ls /sys/class/net/`; do echo $i: `cat /sys/class/net/$i/operstate`; done
    dragonauta · 2012-10-15 18:20:37 0

What Others Think

Hmm. I don't know, but I get a little problem with it on my laptop: sudo mii-tool eth1 SIOCGMIIPHY on 'eth1' failed: Operation not supported Does it not work on WiFi connections? (Probably a stupid question, since it says "network cable")
kaedenn · 469 weeks and 3 days ago
mii is an acronym from the older days when an ethernet card could support multiple physical interfaces (as in twisted pair RJ-45, or coax) and there was a "medium independent interface" layer. I don't know why it doesn't work for your wireless interface, but I know you can use mii-tool to turn off autonegotiation on a wired link for example and force communication at 10 mpbs rather than 100 mpbs or 1gbps. It would save power just like CPU frequency scaling does.
bwoodacre · 469 weeks and 3 days ago
sudo ethtool eth0 "mii-tool" comand was replaced by "ethtool" command.
Playload · 469 weeks and 2 days ago
"mii-tool" is indeed pretty buggy and deprecated nowadays. "ethtool" is preferred. Especially when dealing with Gigabit NICs mii-tool is showing wrong information and doing the wrong thing on several brands of NICs.
Signum · 469 weeks and 1 day ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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