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Zorluk: OrtaTroubleshooting IP Addressing and DHCP Services

A workstation connected to an enterprise network fails to reach internal network resources. A network technician is assigned to troubleshoot the host's IP addressing and DHCP service connectivity. Arrange the diagnostic and troubleshooting steps in the correct order according to standard bottom-up network troubleshooting methodology.

  1. 1Inspect physical network cabling and verify link status light activity on the workstation's network interface card.
  2. 2Execute `ipconfig /all` on the client workstation to inspect the assigned IP configuration and check for an APIPA address (169.254.x.x169.254.x.x).
  3. 3Verify that the access switch port connected to the workstation is assigned to the correct VLAN.
  4. 4Examine the `ip helper-address` configuration on the default gateway router interface serving the workstation's subnet.
  5. 5Inspect the central DHCP server scope statistics to verify lease availability and ensure the IP pool is not exhausted.

Cevap

The correct troubleshooting sequence starts with inspecting physical network cabling and NIC link status, running `ipconfig /all` to evaluate the host IP configuration, verifying switch port VLAN assignment, checking `ip helper-address` (DHCP relay) settings on the default gateway, and finally checking central DHCP server scope statistics for pool exhaustion.
Following standard bottom-up network troubleshooting methodology, a technician verifies physical link connectivity (Layer 1) first, inspects host IP details (`ipconfig /all`) to identify APIPA assignment, checks access switch port VLAN configuration (Layer 2), verifies default gateway DHCP relay (`ip helper-address`) parameters (Layer 3), and finally inspects central DHCP server scope health and lease pool utilization.

Adım Adım Çözüm

1
Inspect Layer 1 physical link connectivity
Confirmed physical media connection and link signal LED activity on the NIC and switch port.
Rule out physical Layer 1 disconnects or faulty patch cables before analyzing protocol configurations.
2
Check local host IP address configuration
Determined the client has auto-assigned an APIPA address (169.254.x.x169.254.x.x).
Identify host-level IP parameters and establish that dynamic IP lease acquisition failed.
3
Verify access switch Layer 2 VLAN assignment
Confirmed the access switch port is assigned to the intended workstation VLAN.
Ensure client traffic resides within the proper broadcast domain and access control segment.
4
Inspect Layer 3 DHCP relay configuration
Verified `ip helper-address` is configured correctly on the gateway subinterface.
Ensure DHCP broadcast requests (255.255.255.255255.255.255.255) are relayed as unicast to the central DHCP server.
5
Verify central DHCP server scope utilization
Confirmed server scope health and available lease pool capacity.
Rule out server-level DHCP scope exhaustion or service failure preventing lease issuance.

Anahtar Kavram

Structured OSI bottom-up troubleshooting methodology applied to IP addressing and DHCP service failures
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