binding—A mapping between the client’s IP and hardware (MAC) addresses. The client’s IP address may be configured by the administrator (manual address allocation) or assigned from a pool by the DHCP server (automatic address allocation). The binding also contains a lease expiration date. The default for the lease expiration date is one day.
conflict—A duplication of use of the same IP address by two hosts. During address assignment, DHCP checks for conflicts using ping and gratuitous (ARP). If a conflict is detected, the address is removed from the pool. The address will not be assigned until the administrator resolves the conflict.
pool—The range of IP addresses assigned by the DHCP server. Address pools are indexed by subnet number.
--An address assignment method where a network administrator obtains an IP address for a client for a finite period of time or until the client explicitly relinquishes the address. Automatic allocation is particularly useful for assigning an address to a client that will be connected to the network only temporarily or for sharing a limited pool of IP addresses among a group of clients that do not need permanent IP addresses. Automatic allocation may also be a good choice for assigning an IP address to a new client being permanently connected to a network where IP addresses are sufficiently scarce that it is important to reclaim them when old clients are retired.
BOOTP—Bootstrap Protocol. A protocol that provides a method for a booting computer to find out its IP address and the location of the boot file with the rest of its parameters.
client—Any host requesting configuration parameters.
database—A collection of address pools and bindings.
agent—Any host storing the DHCP bindings database, for example, a Trivial File Transfer Protocol (TFTP) server.
DHCP—Dynamic Host Configuration Protocol. A protocol that provides a mechanism for allocating IP addresses dynamically so that addresses can be reused when hosts no longer need them.
DNS—Domain Name System. A system used in the Internet for translating names of network nodes into addresses.
allocation—An address assignment method that allocates an administratively assigned IP address to a host. Manual allocation allows DHCP to be used to eliminate the error-prone process of manually configuring hosts with IP addresses.
PWLAN—Public Wireless Local Area Network. A type of wireless LAN, often referred to as a hotspot, that anyone having a properly configured computer device can access.
agent—A device that forwards DHCP and BOOTP messages between a server and a client on different subnets.
server—Any host providing configuration parameters.
SSG—Service Selection Gateway. The feature set that provides on-demand service enforcement within the Cisco network.