Ubuntuで、DHCPサーバからIPアドレスを再取得する

ネットワークのトラブルで、DHCPからIPアドレスを再取得しなければならない場合があります。

Windowsだと、

ipconfig /renew

の1コマンドで再取得できますが、

Ubuntuの場合は、

IPアドレス解放 => 新しいIPアドレスの取得

という手順を踏まなければなりません。

IPアドレスの解放

$sudo dhclient -r
There is already a pid file /var/run/dhclient.pid with pid 2119
killed old client process, removed PID file
Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/vboxnet0/00:00:00:00:00:00
Sending on   LPF/vboxnet0/00:00:00:00:00:00
Listening on LPF/eth0/11:11:11:11:11:11
Sending on   LPF/eth0/11:11:11:11:11:11
Sending on   Socket/fallback
DHCPRELEASE on eth0 to 192.168.100.1 port 67

新しいIPアドレスの取得

$sudo dhclient
Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/vboxnet0/00:00:00:00:00:00
Sending on   LPF/vboxnet0/00:00:00:00:00:00
Listening on LPF/eth0/11:11:11:11:11:11
Sending on   LPF/eth0/11:11:11:11:11:11
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPOFFER of 192.168.100.50 from 192.168.100.1
DHCPREQUEST of 192.168.100.50 on eth0 to 255.255.255.255 port 67
DHCPACK of 192.168.100.50 from 192.168.100.1
bound to 192.168.100.50 -- renewal in 126007 seconds.