DNS, DHCP, and Address Translation

You’ll be able to

Explain core network services
Apply the idea to evidence from a realistic technology scenario
Justify a decision using security, reliability, cost, and user impact

DNS, DHCP, and Address Translation

DHCP supplies host configuration, DNS maps names to records, and NAT translates addresses at a boundary. These services solve different problems. Troubleshooting is faster when symptoms are mapped to the correct dependency.

Decision lens

Strong technical decisions connect evidence → mechanism → impact → response. Identify what the evidence shows, explain the system behavior that produced it, state the likely effect on people or data, and choose a response that addresses the cause without creating unnecessary disruption.

Worked example

A laptop receives 169.254.22.4, cannot reach its gateway, and cannot browse any site.

1.A 169.254/16 self-assigned address often appears when DHCP fails.
2.Check physical or wireless association first.
3.Verify DHCP reachability, scope capacity, and relay configuration.
4.DNS testing is premature because the host lacks valid network configuration.

Answer: Investigate DHCP and local connectivity before blaming name resolution.

Checkpoint

A user can reach `8.8.8.8` but not `example.com`. Which service is the leading suspect?

Checkpoint

Which response best demonstrates complete reasoning about core network services?

On the exam

For a scenario about core network services, identify the decisive evidence before naming a response. A defensible conclusion here is: Investigate DHCP and local connectivity before blaming name resolution.

Answer the 2 checkpoints as you read.