How can I test the current carrier state for an ethernet adapter in Linux?

Question

In Arch Linux, how can I check if a network device (say eth0) has a carrier signal present?

eugene y · Accepted Answer · 2011-11-10 13:01:48Z

up vote 9 down vote accepted

cat /sys/class/net/eth0/carrier is by far the easiest method.

answered Nov 10 '11 at 13:01

eugene y
9572718

Bruce Ediger · Answer 2 · 2011-11-10 18:33:20Z

up vote 5 down vote

If you want that information and more in handy little commands:

mii-tool eth0
ethtool eth0

might do the job.

answered Nov 10 '11 at 18:33

Bruce Ediger
11.3k923

2 Answers