Using multiple DHCP servers correctly, how should scopes be defined so that address assignment works without conflicts or exhaustion?

Introduction / Context:
Dynamic Host Configuration Protocol (DHCP) automates IP address assignment. When deploying multiple DHCP servers, careful scope planning is essential to avoid duplicate leases, address conflicts, and unexpected exhaustion across subnets.

Given Data / Assumptions:

• Environment has multiple subnets/VLANs.
• There are two or more DHCP servers available.
• Goal: reliable assignment with no overlapping pools.

Concept / Approach:
Each subnet needs its own defined scope (pool of addresses and options). With multiple servers, scopes must be non-overlapping for a given subnet or coordinated via split-scope/failover so that no two servers hand out the same address. Practically, servers are configured to serve different subnets or split a subnet’s pool carefully (e.g., 80/20) with proper failover settings.

Step-by-Step Solution:

Verification / Alternative check:
Check lease databases for duplicates; run conflict detection; verify helper-address/relay configuration so requests from each subnet reach the intended DHCP servers.

Why Other Options Are Wrong:

• Unique to that subnet only (ambiguous): a scope should match a subnet, but across multiple servers the key is non-overlapping scopes per subnet, not a vague uniqueness statement.
• No more than two subnets per server: arbitrary and not a protocol rule.
• No subnets/APIPA: would break centralized management.
• None: incorrect because non-overlapping, per-subnet scopes are best practice.

Common Pitfalls:
Overlapping pools between servers, forgetting DHCP relay (IP helper) configuration, and inconsistent option sets that confuse clients.

Final Answer:
For different subnets (non-overlapping scopes per subnet)