What Is DHCP And DNS?

DHCP is a protocol known as Dynamic Host Configuration Protocol. Its main purpose is to assign different IP addresses to devices on a network. Network administrator has to assign IP addresses when a user connects to internet through a machine. By using this protocol network administrator's work become easier because he does not have to assign IP addresses manually as using DHCP this process of assigning IP addresses becomes automated.

DNS is also a internet protocol and is known as Domain Name Server or Domain Name Service. Its purpose is to translate domain names into IP addresses. Whenever we use a domain name, then a service is used for translating domain names into IP addresses and is known as DNS. For example, the domain name www.bigcity.com might translate to 192.103.202.2. So what DNS did in above example as it translates the name "Bigcity" into corresponding IP address.

If one DNS server does not know how to translate the particular domain name it asks another DNS server and this process continued until the correct IP address is returned. As in above example, if one domain server does not know how to translate www.bigcity.com then it will move to another DNS until the corresponding IP address 192.103.202.2 is returned.

As each computer on a certain network needs a unique identification which is in form of IP (Internet Protocol) the DHCP helps the network administrator to centrally control and assign automatic IP to the systems on the network. In huge organizations where computers are many in numbers such scenario the DHCP is very helpful for the administrator because with DHCP server the administrator have to assign IP to each computer manually.

The DHCP is the advance version of the Bootstrap Protocol (BOOTP) which is an earlier IP management protocol. One can use both the protocols depends on the situation but DHCP can handle he client request of BOOTP.

There is an another concept related to DHCP that is called the "LEASE" or in simple words it is the amount of time allowed for each computer to use an assign IP, the time expiry depends on the policy being implemented by the administrator, and is usually short time span of expiry applies in organizations where IPs are limited and computers are more in number. The computers that need a static or permanent IP can also be assign through DHCP servers e.g. Web Server etc.

The Domain Name System(DNS) is like a telephone directory that contains all the information about the host names and it's IPs. As the prime objective of the Domain Name System is to resolve the host's names in to the IPs so for example if you want to find the internet address of any site the Domain Name System will answer you the internet address in IP e.g. the internet address for Google could be 66.27.5.10. In (www.google.com) the right most label which is ".com" in this case is called the Top Level Domain and each to its left side called the "Sub domains".