Recognize an addressing failure

A+ Core 1: Networking
Original starter lesson / sources checked 2026-09-30

DHCP can assign an address, subnet mask, default gateway, and DNS settings. Name resolution and addressing solve different problems.

An IPv4 address in 169.254.0.0/16 can indicate link-local self-assignment when a client cannot obtain a DHCP lease. It is a clue, not proof that one particular device is broken.

Check link state and lease acquisition before changing unrelated application settings. Compare with a working device on the same network.

Hands-on lab

In an isolated lab, inspect network settings and identify the address, gateway, and DNS server.
Describe how you would distinguish a DHCP fault from a name-resolution fault.

Put the lesson to work

Original exam-style practice. Choose the best answer for the stated scenario.

1. A workstation expects DHCP but has 169.254.22.8 and cannot reach remote networks. What is the best initial hypothesis?

A certificate expiredThe client did not obtain a usable DHCP leaseThe browser cache is fullEvery Internet host is down

2. A user can connect to a service by IP address but not by hostname. Which area should you investigate first?

DHCP lease durationThe default gatewayDNS resolutionThe Ethernet link speed

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Official CompTIA scope and exam information

Independent practice aligned to selected topics. No endorsement, actual exam items, or pass guarantee. Verify your exam version and use the full official objectives for complete preparation.