linux强制开启dhcp

 

Linux renew ip command

The -r flag explicitly releases the current lease, and once the lease has been released, the client exits. For example, open terminal and type the command:
$ sudo dhclient -r
Now obtain fresh IP:
$ sudo dhclient

There is no need to restart network service. Above command should work with any Linux distro such as RHEL, Fedora, CentOS, Ubuntu and others. On a related note you can also try out the following commands:
# ifdown eth0
# ifup eth0
# /etc/init.d/network restart
OR
# /etc/init.d/networking restart