Linux IP Command: Get MAC Address

When working with Linux, it's not uncommon to need to retrieve the MAC (Media Access Control) address of an interface. However, if your interfaces don't start with `eth0`, finding the correct MAC address can become a challenge. In this article, we'll explore how to get the MAC address for any available interface that is active.

The first approach is to use the `ip` command, which provides detailed information about network interfaces. To get the MAC address of an interface named `eth1`, you can run the following command:

```bash

sudo ip link show eth1 | grep HWaddr

```

This will display output similar to the following:

```text

3: eth1: mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

link/ether 00:11:22:33:44:55 brd ff:ff:ff:ff:ff:ff

```

In this example, the MAC address is `00:11:22:33:44:55`. Note that you can replace `eth1` with any other interface name to get its corresponding MAC address.

Alternatively, if you don't know the specific interface name, you can use a loop to iterate over all interfaces and check their status:

```bash

for i in /sys/class/net/*; do

if ' -f '$i/operstate' '; then

state=$(cat '$i/operstate')

if ' '$state' = 'up' '; then

mac=$(ip link show '$i' | grep HWaddr)

echo 'Interface: $i, MAC Address: $(echo '$mac' | awk '{print $NF}')'

done

```

This script will iterate over all network interfaces, check their status, and print the interface name and its corresponding MAC address if it's active.

In conclusion, getting the MAC address of an interface in Linux can be achieved using the `ip` command or a loop to iterate over all interfaces. By following these methods, you'll be able to retrieve the MAC address for any available interface that is active, regardless of its name.

Linux ip command get mac address