Understanding and Configuring DHCP Scopes

A DHCP scope defines the pool of IP addresses the DHCP server can assign to clients, along with associated options. Configure DHCP scopes on a Windows Server, router, or dedicated DHCP server. Scope configuration: start and end IP address (the pool range), subnet mask, default gateway (the router's IP), DNS servers (domain controller for AD environments, or 8.8.8.8/1.1.1.1 for simple networks), lease duration (24 hours is standard; shorter for public/guest networks to reclaim addresses faster, longer for stable office environments), and exclusions (IP addresses within the pool range that should never be assigned, such as statically-configured devices). For multiple VLANs, configure separate DHCP scopes for each VLAN subnet. The DHCP server must either reside on each subnet or use a DHCP relay/helper agent on the router to forward DHCP requests from other subnets to a central DHCP server. Monitor scope utilization — if a scope is more than 80% utilized, expand it or reduce lease times to reclaim unused addresses more quickly.