A network administrator is troubleshooting an issue where hosts on a newly provisioned user subnet (VLAN 50, ) are receiving APIPA IPv4 addresses () instead of valid leases from the central DHCP server located on VLAN 10 (). Place the diagnostic and remediation steps in the correct logical sequence from initial verification to final resolution confirmation.
- 1Run `ipconfig /all` on a client workstation on VLAN 50 to verify that DHCP is enabled and that no static IP conflict exists.
- 2Inspect the VLAN 50 layer 3 gateway interface configuration on the switch/router to verify the presence of an `ip helper-address 10.10.10.2` statement.
- 3Apply `ip helper-address 10.10.10.2` to the VLAN 50 interface and verify firewall access control lists (ACLs) permit UDP ports 67 and 68 between subnets.
- 4Execute `ipconfig /renew` on the client workstation and run `ipconfig /all` to confirm a valid lease, default gateway, and DNS settings.
Answer
The correct logical order begins with host configuration verification (`ipconfig /all`), followed by checking the gateway's DHCP relay (`ip helper-address`) configuration, applying the missing relay/ACL configuration, and concluding with host lease renewal (`ipconfig /renew`) to verify full functionality.
Following standard network troubleshooting methodology, an engineer first identifies the problem at the client host by checking `ipconfig /all`. Because the host has an APIPA address () and resides on a separate subnet from the DHCP server, the engineer must next inspect the gateway router for a missing `ip helper-address`. Once identified, configuring the helper address and verifying UDP 67/68 traffic flow remediates the relay failure. Finally, forcing a lease renewal with `ipconfig /renew` on the client confirms full operational recovery.
Step-by-Step Solution
Key Concept
DHCP Relay and Helper Address Troubleshooting across Layer 3 Subnets