DHCP Troubleshooting: Follow the Address Request
A practical workflow for clients that cannot obtain an address or receive the wrong DHCP information.
Find the last successful DHCP step
Treat DHCP as an exchange: Discover, Offer, Request, Acknowledge. Determine whether the client sends a discovery, whether a server offer returns, and where the sequence stops. A capture near the client or relay often makes the failure stage obvious.
If the client sends nothing, stay local. If the discovery leaves but no offer returns, move toward relay, routing, firewall, and server checks.
Check relay and scope health
For routed clients, verify the helper/relay address, source interface, VRF, and route to the server. The server also needs a working return path to the relay address.
On the server side, check scope exhaustion, exclusions, subnet mask, gateway, DNS options, reservations, and policies. A reachable server can still ignore or incorrectly answer a request.
Verify with a clean renewal
After the correction, force a fresh DHCP renewal and inspect the complete lease, not just whether an address appears. Stale gateways or DNS servers can keep the user broken even after the address problem is fixed.
Document the exact failing stage and the affected scope so future incidents can be isolated faster.