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I'm new to linux and I have server with four network cards. I have to identify which physical network interface is assigned to the names eth0, eth1, eth2 and eth3. I have to disconnect cable from eth2 and do not know which network card it is.


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marked as duplicate by Iain, Dave M, mdpc, dawud, Falcon Momot Sep 29 '13 at 20:02

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up vote 23 down vote accepted

You can use ethtool.

ethtool -p ethX [N]
  • ethX – network interface name
  • [N] – number of second to blink


ethtool -p eth2 15

This will blink the network interface eth2 for 15 seconds, then you can see which physical network interface is for eth2

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to check the Physical link in linux, use miitool.

It shows if your network card is connected or not.

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This will tell you if anything is connected, and the utility can help control the interface, but it is of very little help in differentiating them. A particular feature of ethtool which allows manual control of the LEDs is sometimes helpful. – Falcon Momot Sep 28 '13 at 7:28

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