[Linux] 自分のIPアドレスを確認する方法
Linuxで自分のIPアドレスを確認するためのコマンドは、Ubuntu 20.04 LTS、Red Hat Enterprise Linux 8、CentOS 8であれば、ipコマンド、hostnameコマンドで確認できる。
Ubuntu 20.04 LTSのコンソール画面でIPアドレス確認コマンド「ip a」の実行結果（例）
実行結果画面
nobu@yukio-pc:~$ ip a
17: eth0: <> mtu 1500 group default qlen 1
link/ether b8:31:b5:78:f9:50
inet 169.254.16.68/16 brd 169.254.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 fe80::4dac:875f:f3b6:1044/64 scope link dynamic
valid_lft forever preferred_lft forever
20: eth1: <> mtu 1500 group default qlen 1
link/ether 00:09:0f:fe:00:01
inet 169.254.80.104/16 brd 169.254.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 fe80::acea:2697:7d65:5068/64 scope link dynamic
valid_lft forever preferred_lft forever
5: eth2: <> mtu 1392 group default qlen 1
link/ether 00:09:0f:aa:00:01
inet 169.254.81.100/16 brd 169.254.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 fe80::394a:c204:415e:5164/64 scope link dynamic
valid_lft forever preferred_lft forever
1: lo: mtu 1500 group default qlen 1
link/loopback 00:00:00:00:00:00
inet 127.0.0.1/8 brd 127.255.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host dynamic
valid_lft forever preferred_lft forever
13: wifi0: mtu 1500 group default qlen 1
link/ieee802.11 b8:31:b5:78:f9:4f
inet 192.168.0.17/24 brd 192.168.0.255 scope global dynamic
valid_lft 86034sec preferred_lft 86034sec
inet6 2001:318:2100:f71:f5fb:f8fd:149:1d57/64 scope global dynamic
valid_lft 280sec preferred_lft 280sec
inet6 2001:318:2100:f71:9fc:6dda:1296:b6af/128 scope global dynamic
valid_lft 280sec preferred_lft 280sec
inet6 fe80::f5fb:f8fd:149:1d57/64 scope link dynamic
valid_lft forever preferred_lft forever
10: wifi1: <> mtu 1500 group default qlen 1
link/ieee802.11 ba:31:b5:78:f8:4e
inet 169.254.73.51/16 brd 169.254.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 fe80::45fc:d6c6:3437:4933/64 scope link dynamic
valid_lft forever preferred_lft forever
11: wifi2: <> mtu 1500 group default qlen 1
link/ieee802.11 ba:31:b5:78:fd:4e
17: eth0: <> mtu 1500 group default qlen 1
link/ether b8:31:b5:78:f9:50
inet 169.254.16.68/16 brd 169.254.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 fe80::4dac:875f:f3b6:1044/64 scope link dynamic
valid_lft forever preferred_lft forever
20: eth1: <> mtu 1500 group default qlen 1
link/ether 00:09:0f:fe:00:01
inet 169.254.80.104/16 brd 169.254.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 fe80::acea:2697:7d65:5068/64 scope link dynamic
valid_lft forever preferred_lft forever
5: eth2: <> mtu 1392 group default qlen 1
link/ether 00:09:0f:aa:00:01
inet 169.254.81.100/16 brd 169.254.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 fe80::394a:c204:415e:5164/64 scope link dynamic
valid_lft forever preferred_lft forever
1: lo:
link/loopback 00:00:00:00:00:00
inet 127.0.0.1/8 brd 127.255.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host dynamic
valid_lft forever preferred_lft forever
13: wifi0:
link/ieee802.11 b8:31:b5:78:f9:4f
inet 192.168.0.17/24 brd 192.168.0.255 scope global dynamic
valid_lft 86034sec preferred_lft 86034sec
inet6 2001:318:2100:f71:f5fb:f8fd:149:1d57/64 scope global dynamic
valid_lft 280sec preferred_lft 280sec
inet6 2001:318:2100:f71:9fc:6dda:1296:b6af/128 scope global dynamic
valid_lft 280sec preferred_lft 280sec
inet6 fe80::f5fb:f8fd:149:1d57/64 scope link dynamic
valid_lft forever preferred_lft forever
10: wifi1: <> mtu 1500 group default qlen 1
link/ieee802.11 ba:31:b5:78:f8:4e
inet 169.254.73.51/16 brd 169.254.255.255 scope global dynamic
valid_lft forever preferred_lft forever
inet6 fe80::45fc:d6c6:3437:4933/64 scope link dynamic
valid_lft forever preferred_lft forever
11: wifi2: <> mtu 1500 group default qlen 1
link/ieee802.11 ba:31:b5:78:fd:4e
Ubuntu 20.04 LTSのコンソール画面でIPアドレス確認コマンド「hostname -I」の実行結果（例）
hostnameのオプションは小文字のiではなく、大文字のIを使用することに注意。
実行結果画面
nobu@yukio-pc:~$ hostname -I
192.168.0.17 2001:318:2100:f71:f5fb:f8fd:149:1d57 2001:318:2100:f71:7d3a:d6a2:a7b4:993
192.168.0.17 2001:318:2100:f71:f5fb:f8fd:149:1d57 2001:318:2100:f71:7d3a:d6a2:a7b4:993