Subtitles of the Movie

DHCP Servers and Leases. DHCP is short for the Dynamic Host Configuration Protocol. It's a way to ration IP addresses on the Internet and other similar networks. When a system connects it gets IP and other related address information from that DHCP Server. While DHCP is most commonly associated with IP Version 4 addressing, its also useful for IP Version 6 Networks as that server can tell clients about routing, DNS, Network Time Protocol and even Win Services also known as NetBIOS Name servers. As you can see from this CentOS example it can even set-up a Network Information Service Domain and tell clients about the local domain name. These directives specify things like the Domain name, the DNS server, the Network Time Protocol server; the NetBIOS name server or Win Server as well as the NIS domain. The range is the group of assignable IP addresses, in this case between 128 and 254 on this 192.168.0.0 network. Each IP address is assigned for some given lease time in seconds. The Routers Directive provides information on the gateway, so each DHCP Client knows how to send information outside the network. Of course a subnet mask is useful in that respect and if you have to have a fixed IP Address for a system you can set-up a stanza like this, where a name server or a DNS server given this particular hardware address on its network card is given a specific IP Address. You can use the same pattern of course to set up a fixed IP address for the systems of your choice. The DHCP Server Configuration File is dhcpd.conf depending on your distribution and the release of the DHCP Server you may find that file in either in the etc. or etc/dhcp3 directories. Once IP Addresses are assigned the leases are maintained on the DHCP Server in one of these two directories. Well those are the basics of DHCP Servers and Leases. Thanks and on to the next video.