Qtech QSW-3900-48-SFP-DC [145/245] Dhcp configuration

QTECH Software Configuration Manual

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Chapter 11 DHCP Configuration

11.1 Brief introduction of DHCP

Dynamic Host Configuration Protocol (DHCP) is a network application protocol used by devices (DHCP

clients) to obtain configuration information for operation in an Internet Protocol network. This protocol reduces

system administration workload, allowing devices to be added to the network with little or no manual intervention.

DHCP was initially defined in RFC 1531 as a standard-track protocol in October 1993, succeeding the BOOTP. The

next update, RFC 2131 released in 1997 is the current DHCP definition for IPv4 networks. The extensions of DHCP

for IPv6 (DHCPv6) were published as RFC 3315.

Technical oange of IP addresses to DHCP, and each client computer on the LAN has its IP software

configured to request an IP address from the DHCP 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 (dynamic re-use of IP addresses).

With networks getting larger in size and more complicated in structure, lack of available IP addresses becomes

the common situation the network administrators have to face, and network configuration becomes a tough task for

the network administrators. With the emerging of wireless networks and the using of laptops, the position change of

hosts and frequent change of IP addresses also require new technology. Dynamic host configuration protocol (DHCP)

is developed in this background.

DHCP adopts a client/server model, where DHCP clients send requests to DHCP servers for configuration

parameters; and the DHCP servers return the corresponding configuration information such as IP addresses to

configure IP addresses dynamically.

A typical DHCP application includes one DHCP server and multiple clients (such as PCs and laptops), as

shown below.

Typical DHCP application