This is an alternative DHCP client, the ISC DHCP client for Linux. Like
"dhcpcd" (the client that is installed by default), it can be used to
configure the network setup. IP address, hostname, routing,
nameserver, netmask, and broadcast can be dynamically assigned while
booting the machine.
It is configurable via the configuration file /etc/dhclient.conf and
you can define your own 'hooks' to be used by the /sbin/dhclient-script
(which is called by the daemon).