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IGCSE · Practice questions · How a web page is located and retrieved: DNS

Look it up, then fetch.

Six original Cambridge-style questions on DNS and retrieving web pages, with mark-scheme style solutions.

Original questions All questions on this page are original work, written in the Cambridge IGCSE style. They are not from past papers. They test the same concepts and skills the syllabus rewards.
Keep these straight

One job each.

01
Explain
[6 marks]

A user enters a URL into a web browser. Describe how the web page is located, retrieved and displayed.

  • The browser sends the domain name (from the URL) to a DNS. ✓
  • The DNS searches its database for the matching IP address (passing the request to another DNS if it is not found). ✓
  • The DNS returns the IP address to the browser. ✓
  • The browser sends a request to the web server at that IP address. ✓
  • The web server sends the web page files / HTML to the browser. ✓
  • The browser renders the HTML and displays the web page. ✓
02
Recall
[1 marks]

State what is meant by DNS.

  • Domain name server: a server that stores domain names and their matching IP addresses. ✓
03
Explain
[2 marks]

Explain why a DNS is needed when a user enters a URL.

  • Users enter a text-based domain name, but devices on the internet are located using IP addresses. ✓
  • The DNS translates the domain name into the IP address of the web server. ✓
04
Apply
[2 marks]

A DNS receives a request for a domain name that is not in its database. Describe what happens next.

  • The DNS passes the request on to another DNS (higher up). ✓
  • If that DNS finds it, the IP address is returned to the browser; if no DNS holds it, an error message is returned. ✓
05
Recall
[2 marks]

State the role of the web server and the role of HTML in displaying a web page.

  • Web server: stores the web page files and sends them to the browser when requested. ✓
  • HTML: the language the page is written in, which the browser renders to display the page. ✓
06
Analysis
[2 marks]

A student writes: "The browser sends the URL to the DNS, which sends back the web page." Identify and correct the error.

  • The DNS does not send the web page; it sends back the IP address of the web server. ✓
  • The browser then requests the page from the web server, which sends the HTML. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.