Monday, September 12, 2016

DHCP

  • DHCP means Dynamic Host Control Protocol.
  • DHCP is used to allocate the IP address to the Requested computer.
  • DHCP means dynamic.Because, Instead of having just one fixed IP address and specific IPaddress,Most computers will be assigned dynamically by DHCP server.

DHCP Client :

  • A computer which is going to get the IP address from the DHCP server.

DHCP Server :

  • A computer running the DHCP Server service that holds information about available IP addresses and related configuration information as defined by the DHCP administrator and responds to requests from DHCP clients.


How DHCP is working ?

Here is how the DHCP process works when you go online :
  • Your go on your computer to connect to the Internet.
  • The network requests an IP address (this is actually referred to as a DHCP discover message).
  • On behalf of your computer's request, the DHCP server allocates (leases) to your computer an IP address. This is referred to as the DHCP offer message.
  • Your computer (remember—you're the DHCP client) takes the first IP address offer that comes along. It then responds with a DHCP request message that verifies the IP address that's been offered and accepted.
  • DHCP then updates the appropriate network servers with the IP address and other configuration information for your computer.
  • Your computer (or whatever network device you're using) accepts the IP address for the lease term.


Why DHCP ?

  • Valid TCP/IP configuration parameters for all clients on the network.
  • Valid IP addresses, maintained in a pool for assignment to clients, as well as excluded addresses.
  • Reserved IP addresses associated with particular DHCP clients. This allows consistent assignment of a single IP address to a single DHCP client.
  • The lease duration, or the length of time for which the IP address can be used before a lease renewal is required.

Advantages of DHCP :

  • Reliable IP address configuration :
    • DHCP reduces the configuration errors like,manual Typing errors,address duplication.
  • Reduced network administration : 
    • The efficient handling of IP address changes for clients that must be updated frequently, such as those for portable computers that move to different locations on a wireless network.
    • The ability to define TCP/IP configurations from a central location.