7.1 INTRODUCTION

Dynamic Host Configuration Protocol (DHCP), which has been extensively used in IPv4 network, helps hosts to configure IP addresses as well as some additional information. It may save the network management cost by minimizing the involvement of network administrator in configuration of newly introduced hosts. It is used as a mechanism to provide portability to the mobile terminal. It also helps Mobile IPv4 when there is no foreign agent. If there are no foreign agents in Mobile IPv4, ^[2] Care-of-Address (CoA) should be provided by DHCP servers. Thus, it is widely adopted in various applications such as wireless LAN, campus network, and offices of the global company.

DHCP servers pass network configuration parameters to hosts on the network and further support automatic reusability of addresses in networks. DHCP allows managing address resources and related information in a concentrated manner, resulting in reducing network management costs.

DHCPv6 ^[1] is classified as a stateful configuration protocol, which is explained with stateless address autoconfiguration protocol in Chapter 6. ^[3], ^[4] Hosts do not specially need DHCP to get IP address in IPv6 networks because any host is able to get globally unique IP address via stateless address autoconfiguration. However, in some networks, strict address management or dynamic assignment feature using DHCP servers becomes more important than benefits which can be obtained if stateless configuration mechanism is employed. In such cases, network administrators may adopt DHCPv6 in a network for the configuration of addresses as well as additional...