Linux Administration Cookbook

Shutting down and bringing up an interface administratively

To work with the interface itself, we need to use another element of the ip suite, this being ip link. Note again the use of sudo:

$ sudo ip link set eth1 down

Checking our interfaces, we can see that the interface is in the DOWN state:

3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000    link/ether 08:00:27:0d:d9:0c brd ff:ff:ff:ff:ff:ff    inet 192.168.33.10/24 brd 192.168.33.255 scope global noprefixroute eth1       valid_lft forever preferred_lft forever

You will find yourself unable to ping this host from centos2.

To bring an interface back up, simply run the following:

$ sudo ip link set eth1 up

Note that if you add another IP to an interface on ...