This assumes you are familiar with the /etc/sudoers file.
Use the visudo command to edit the /etc/sudoers file. The syntax of lines in the /etc/sudoers file is users hosts=(user:group) commands. In this example, user john.doe is given permission to issue the ifup and ifdown commands using sudo.
john.doe ALL=(ALL:ALL) /sbin/ifup, /sbin/ifdown
The NOPASSWD option can be included to ensure that the sudo command does not prompt the user for their password.
john.doe ALL=(ALL:ALL) NOPASSWD: /sbin/ifup, /sbin/ifdown