BOOTP and DHCP

Bootp:bootstrap PROTOCOL RFC 951 Http://www.ietf.org/rfc/rfc951.txt

Dhcp:dynamic Host Configuration Protocol RFC 2131 http://www.ietf.org/rfc/rfc2131.txt

The bootstrap protocol (BOOTP) is a host configuration protocol developed prior to DHCP and is mainly used in diskless workstation networks. The DHCP protocol is improved on the basis of BOOTP and eliminates the special limitations of BOOTP as host Configuration service.

1. DHCP is almost identical to the BOOTP protocol package format

DHCP is basically consistent with the BOOTP packet protocol, which is that in the end, carrying data segments is different and the rest are the same: the final header field for carrying optional data. For BOOTP, this optional field is referred to as a "specific vendor zone" and is limited to 64 eight-bit bytes. For DHCP, the zone is called an "option" field and can carry up to 312 eight-byte DHCP option information.

2. Communication mode, communication port is consistent

Both BOOTP and DHCP use the same reserved protocol port to send and receive messages between the server and the client. Both BOOTP and DHCP servers use the number 67th UDP port to listen and receive client request messages. BOOTP and DHCP clients typically retain the number 68th UDP port to receive message replies from either the BOOTP server or the DHCP server.

Because DHCP and BOOTP messages use almost the same format type and packet structure, and generally use the same well-known service ports, BOOTP and DHCP relay agents typically treat BOOTP and DHCP messages as essentially the same message types without distinction.

3. Distribution Mode

Both BOOTP and DHCP assign IP addresses to clients during startup, except that they use different allocation methods. BOOTP typically provides a fixed allocation of a single IP address for each client and retains it permanently in the BOOTP server database. DHCP typically provides dynamic, leased allocations of available IP addresses, and temporarily retains each DHCP client address in the DHCP server database.