【Linux】ネットワークインターフェースの番号（インデックス）を確認するコマンド

コマンド自体は極めてオーソドックス。 ip link show で表示される番号が該当してるっぽい。

 % ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen
 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc mq state UP mode DEFAULT group default ql
en 1000
    link/ether 0a:16:53:d0:fc:80 brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc mq state UP mode DEFAULT group default ql
en 1000
    link/ether 0a:2b:38:3d:bb:0a brd ff:ff:ff:ff:ff:ff
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc mq state UP mode DEFAULT group default ql
en 1000
    link/ether 0a:aa:c9:62:6e:fa brd ff:ff:ff:ff:ff:ff
5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT grou
p default 
    link/ether 02:42:dc:ed:12:78 brd ff:ff:ff:ff:ff:ff
6: br-5ec1c975db31: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFA
ULT group default 
    link/ether 02:42:f9:7d:c3:56 brd ff:ff:ff:ff:ff:ff

参考

sysfs - Is it possible to get network interface index not via /sys? - Unix & Linux Stack Exchange https://unix.stackexchange.com/questions/150216/is-it-possible-to-get-network-interface-index-not-via-sys