|
Protokol BOOTP sendiri pertama kali ditakrifkan dalam RFC 951 sebagai pengganti Protokol Penyelesai Alamat Songsang ("Reverse Address Resolution Protocol-RARP".) Motivasi utama untuk menukar RARP dengan BOOTP adalah bahawa RARP adalah protokol lapis sambungan data. Hal ini menyulitkan pelaksanaan di kebanyakan platform pelayan, dan memerlukan pelayan terdapat pada setiap sambungan rangkaian individu. BOOTP memperkenalkan inovasi agen geganti, yang membolehkan paket BOOTP dihantar ke rangkaian tempatan dengan menggunakan routing IP piwaian, agar satu pusat pelayan BOOTP boleh melayani hos banyak subrangkaian IP.<ref>{{cite web|url=http://tools.ietf.org/html/rfc951#section-6 |title=RFC 951 - Bootstrap Protocol |author=Bill Croft|author2=John Gilmore|date=September 1985|work=Network Working Group }}</ref>
==overview teknikal==
Dynamic Host Configuration Protocol automates network-parameter assignment to network devices from one or more DHCP servers. Even in small networks, DHCP is useful because it makes it easy to add new machines to the network.
When a DHCP-configured client (a computer or any other network-aware device) connects to a network, the DHCP client sends a [[Broadcasting (computing)|broadcast]] query requesting necessary information from a DHCP server. The DHCP server manages a pool of IP addresses and information about client configuration parameters such as [[default gateway]], [[domain name]], the [[name server]]s, other servers such as [[time server]]s, and so forth. On receiving a valid request, the server assigns the computer an IP address, a lease (length of time the allocation is valid), and other IP configuration parameters, such as the [[subnet mask]] and the [[default gateway]]. The query is typically initiated immediately after [[booting]], and must complete before the client can initiate [[Internet Protocol|IP]]-based communication with other hosts.
Depending on implementation, the DHCP server may have three methods of allocating IP-addresses:
* ''dynamic allocation'': A [[network administrator]] assigns a range of IP addresses to DHCP, and each client computer on the LAN is configured to request an IP address from the DHCP [[Server (computing)|server]] during network initialization. The request-and-grant process uses a lease concept with a controllable time period, allowing the DHCP server to reclaim (and then reallocate) IP addresses that are not renewed.
*''automatic allocation'': The DHCP server permanently assigns a free IP address to a requesting client from the range defined by the administrator. This is like dynamic allocation, but the DHCP server keeps a table of past IP address assignments, so that it can preferentially assign to a client the same IP address that the client previously had.
* ''static allocation'': The DHCP server allocates an IP address based on a table with [[MAC address]]/[[IP address]] pairs, which are manually filled in (perhaps by a [[network administrator]]). Only requesting clients with a MAC address listed in this table will be allocated an IP address. This feature (which is not supported by all DHCP servers) is variously called ''Static DHCP Assignment'' (by [[DD-WRT]]), ''fixed-address'' (by the dhcpd documentation), ''Address Reservation'' (by Netgear), ''DHCP reservation'' or ''Static DHCP'' (by Cisco/[[Linksys]]), and ''IP reservation'' or ''MAC/IP binding'' (by various other router manufacturers).
==Technical details==
| 