Practical Android networking

How to Test DNS from Android

Query the hostname using the current network resolver, compare with a trusted custom resolver, and separate DNS failure from host reachability.

Quick steps

1. Check that the phone has basic network access.
2. Use the DNS tool with the network-provided resolver.
3. Repeat with an authorized custom resolver for comparison.
4. Test the returned IP separately when the name resolves but the service fails.

What the result means

Ping sends ICMP echo requests and measures replies. Round-trip time reflects the complete path at that moment, including WiFi conditions, routing, device load, and response handling.

Ping is a fast first check for whether a local host responds and how long packets take to return. Repeated samples help distinguish a total outage from intermittent latency or packet loss.

Troubleshooting

Repeat the test from the same network and preserve one variable at a time. Check basic reachability first, then move to the protocol-specific test. A single timeout is not enough to identify the failing component.

• DNS caches can retain old answers until their TTL expires.
• Private local names may only resolve through the router or company DNS.
• A successful DNS answer does not prove that the destination service is online.

Common mistakes

• Testing a device on another guest network or VLAN without a route.
• Assuming one scan is a permanent inventory rather than a point-in-time observation.
• Changing several router or device settings before retesting each change.

Use Network Toolkit

Open Ping Tool for Android for the detailed workflow, limitations, and related tools. Use diagnostics only on systems you own or administer.

Frequently asked questions