DNS guide | Layeratek

WHAT YOU’LL BE ABLE TO DO

Explain the resolver’s role and distinguish name resolution from connecting to a service.

Ask a specific question

DNS stores different kinds of records. An A record associates a name with an IPv4 address; an AAAA record is for IPv6. A successful answer does not prove the application is available.

Name lookup → address answer → a separate connection attempt

Follow the hierarchy

When a recursive resolver needs an uncached answer, it may follow referrals from root to top-level domain to an authoritative server. Cached information can shorten that process.

Root → top-level domain → authoritative answer

Account for the cache

A record’s time to live limits how long a cached copy can be reused. An unexpired cached answer can avoid repeating the full lookup.

Compare a fresh lookup with a cache hit in the lab.

Further reading: DNS concepts (RFC 1034)

PUT THE IDEA TO WORK

Check your reasoning.

A name resolves successfully, but the website fails to load. What follows?

Before you move on

Use these prompts to decide what to revisit.

I can separate a DNS answer from an application response.I can name the resolver’s job.I can explain why two lookups may take different paths.

0 of 3 reflection prompts checked

FROM EXPLANATION TO EXPLORATION

Now change something.

Run the DNS lab with and without a cached answer. Describe the steps that disappear.

Trace a DNS lookup

Follow the name, then the address.

Ask a specific question

Follow the hierarchy

Account for the cache

Check your reasoning.

Before you move on

Now change something.

Take the next step.

Let the evidence lead.

A subnet, one step at a time.