DHCP Server Configuration

Overview

• DHCP (Dynamic Host Configuration Protocol) allows devices on a network to request and obtain an IP address from a DHCP server.
• DHCP servers require configuration to define IP address pools, lease durations, and other network settings.

DHCP Scope

• Scope: A range of IP addresses that the DHCP server can assign to devices.
  • Includes IP address range, subnet mask, and any excluded addresses.
  • Determines lease duration for IP addresses.
  • Additional options like DNS server configurations, default gateways, and more.
• Subnet-based Pools: IP addresses are assigned per subnet, often in a contiguous range (e.g., addresses 1-100).
• Address Exclusions: Specific addresses that should not be assigned.

Address Reservations

• Reservations: Ensures certain devices always receive the same IP address based on their MAC address.
  • Useful for devices like printers and servers.
  • Known as static DHCP assignment or IP reservation.
• Configuration: Can be set up in DHCP server settings using a table of MAC addresses.

Lease Period

• Lease Time: IP addresses are leased for a temporary period; configurable by the DHCP administrator.
• Renewal Process:
  • T1 Timer: At 50% of lease time, device attempts to renew with the original DHCP server.
  • T2 Timer: At 87.5% of lease time, device tries to renew with any DHCP server if the original is unavailable.
• Example: For an 8-day lease, T1 is 4 days, and T2 is 7 days.

Optional DHCP Features

• DHCP Options: Allow configuration of additional TCP/IP settings beyond basic network info.
  • Options List: 254 usable options are available, each identified by a number.
  • Common options include IP address, subnet mask, default gateway, and DNS servers.
  • Vendor Extensions: Formerly known in boot P days, allow setting additional configurations like voice over IP (option 129) or HTTP proxy (option 135).
• Server Options: Configure DHCP options within DHCP server settings.

Practical Application

• Demonstration of DHCP server settings in Windows Server.
• Example of configured scopes and reservations with specific IPs and associated MAC addresses.
• Importance of centralized DHCP management for efficient network administration.