ifup/ifdown

이 녀석들은 데비안 출신이었나?

5.3.5. The network interface with the static IP The network interface served by the static IP is configured by creating the configuration entry in the "/etc/network/interfaces" file as the following. allow-hotplug eth0 iface eth0 inet static address 192.168.11.100 netmask 255.255.255.0 broadcast 192.168.11.255 gateway 192.168.11.1 dns-domain lan dns-nameservers 192.168.11.1 When the Linux kernel detects the physical interface eth0, the allow-hotplug stanza will cause ifup to bring up the interface and the iface stanza will cause ifup to use the static IP to configure the interface. [링크 : http://www.debian.org/doc/manuals/debian-reference/ch05.en.html#_the_network_interface_with_the_static_ip]

간단하게 해석하자면, 물리적으로 연결이 되었음을 탐지하게 되면, 자동으로 설정을 실행한다는 의미이다.
(interface-eth0-를 up 시키고 iface구절을 실행함)

Check to see if a Network Link/Interface is up|down ip link show eth0 //the iproute package is required. If there is no ip package, apt-get install iproute If eth0 has a Network link, the following will be returned: 2: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:0c:29:26:57:4e brd ff:ff:ff:ff:ff:ff If eth0 has no Network link, the following will be returned: 2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:0c:29:26:57:4e brd ff:ff:ff:ff:ff:ff The "UP" is the operative word. [링크 : http://wiki.kartbuilding.net/index.php/Ifup-ifdown]

실제로 ifup, ifdown 시에 제대로 interface가 up / down 되었는지 확인하는 방법이다.