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The TCP/IP Guide  9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)       9  TCP/IP Network Configuration and Management Protocols (BOOTP, DHCP, SNMP and RMON)            9  Host Configuration and TCP/IP Host Configuration Protocols (BOOTP and DHCP)                 9  TCP/IP Dynamic Host Configuration Protocol (DHCP)                      9  DHCP Address Assignment and Dynamic Address Allocation and Management

DHCP Lease "Life Cycle" Overview (Allocation, Reallocation, Renewal, Rebinding and Release) and Lease Timers 1 2 3 4 DHCP Configuration and Operation

Simple Address Assignment For a Single Scope

The exact method for setting up scopes depends on the particular operating system and DHCP server software, and I am not going to get into that here. However, each scope definition typically begins by specifying a range of addresses using a starting and an ending IP address. For example, if a company was assigned the IP address block 111.14.56.0/24, the administrator might set up a scope encompassing addresses 111.14.56.20 through 111.14.56.254, as shown in Figure 260. Then for that scope, the administrator can set up various parameters to be specified to each client assigned an address from the scope.

Why not start at 111.14.56.1? Usually we will want to set aside certain IP addresses for manual configuration of servers, routers and other devices requiring a fixed address. One easy way to do that is to simply reserve a block of addresses that aren't used by DHCP. Alternately, most DHCP server software will allow you to specify a range but exclude an address or set of addresses from the range. So we could specify 111.14.56.1 through 111.14.56.254 and individually mark as “not available” addresses we manually assign. Or specify that 111.14.56.1 through 111.14.56.19 are reserved.

DHCP Lease "Life Cycle" Overview (Allocation, Reallocation, Renewal, Rebinding and Release) and Lease Timers 1 2 3 4 DHCP Configuration and Operation