A little learning. A little more confidence.Your next step starts here

Network foundations · Lesson 1 of 5

From a name to a destination

The Domain Name System, or DNS, helps applications find information associated with a domain name. A common use is resolving a website name to an IP address.

SEE THE IDEA

A name becomes a destination

Simplified lookup for the fictional name training.example.

  1. Your device

    Asks for an address associated with training.example.

  2. Recursive resolver

    Uses a valid cached answer or asks DNS servers.

  3. Address returned

    Example answer: 192.0.2.40. Your device can then attempt a connection.

An uncached lookup can involve root, top-level-domain, and authoritative servers. The resolver returns the answer to the device; website traffic is a separate connection.
Read the visualDoes getting an address mean the website is trustworthy?

No. DNS resolution finds records associated with a name. It does not endorse the site or its requests.

Names and addresses are different

A domain is a human-friendly name. An IP address identifies an endpoint in the network addressing system.

Resolvers do the lookup

A recursive resolver can ask other DNS servers for an answer, then cache that answer for a limited period.

A result is not a trust decision

Finding an address does not establish that a website or its content is safe.

Put it in context

You enter training.example. Your browser needs an address before connecting. A cached answer may save another lookup, but it does not tell you whether the training is legitimate.

DNS helps you find a destination. It does not decide whether you should trust it.

Read the sources

Make it stick.

Try one short question to check your understanding and save this lesson to your progress.

YOUR LEARNING SPACE