# How I combine small network tools when debugging connectivity

A beginner-friendly guide to using DNS, IP, port, URL, and header tools together instead of guessing from one signal.

- Date: 2026-09-27
- URL: https://ilham.dev/posts/how-to-build-dns-and-network-notes-from-small-tools/
- Markdown: https://ilham.dev/posts/how-to-build-dns-and-network-notes-from-small-tools/index.md
- Tags: networking, debugging, dns, tools
- Reading time: 2 min


Network debugging usually needs more than one clue. DNS, IPs, ports, URLs, and headers each answer a different question.

I use [Network tools](/tools/dns-lookup/) for the quick version of this task, then I review the output before relying on it.

## The simple idea

Network debugging usually needs more than one clue. DNS, IPs, ports, URLs, and headers each answer a different question.

The tool is a shortcut for the mechanical work. It does not remove the need to understand what the result means.

## Step 1: Start with the URL being tested

Start with the URL being tested.

## Step 2: Parse the URL into host, path, and query

Parse the URL into host, path, and query.

## Step 3: Look up DNS records for the host

Look up DNS records for the host.

## Step 4: Check the resolved IP context if needed

Check the resolved IP context if needed.

## Step 5: Check whether the expected port and protocol make sense

Check whether the expected port and protocol make sense.

## Step 6: Inspect HTTP headers after the server responds

Inspect HTTP headers after the server responds.

## Step 7: Write down each finding instead of jumping to conclusions

Write down each finding instead of jumping to conclusions.

## My checklist

Before I trust the result, I check:

- Start with the URL being tested.
- Parse the URL into host, path, and query.
- Look up DNS records for the host.
- Check the resolved IP context if needed.
- Check whether the expected port and protocol make sense.
- Inspect HTTP headers after the server responds.
- Write down each finding instead of jumping to conclusions.

That review step is what keeps a quick tool from becoming a quick mistake.