Understanding DNS Lookup - Free HTML Lessons | Full Stack Web Development | Nextsem

1. What is DNS?

1. DNS translates website names into numbers.

2. Computers only understand numerical IP addresses.

3. DNS works like your phone contacts.

4. You type names, DNS finds numbers.

5. Browsers connect instantly using IP numbers.

Example

Try it Yourself »

<!DOCTYPE html>

<head>

<title>DNS Lookup Demo</title>

</head>

<body>

<h1>Domain Name System</h1>

<p>Translating nextsem.online to 199.36.158.100.</p>

</body>

</html>

2. The DNS Resolution Chain

1. Browser checks local device DNS cache.

2. Router forwards query to internet provider.

3. Root servers direct query to TLD.

4. TLD server locates authoritative name server.

5. Authoritative server returns final website IP.

3. Querying DNS with nslookup

1. Open Windows Terminal on your PC.

2. Type nslookup followed by domain name.

3. DNS server resolves requested web address.

4. Output displays matching destination IP address.

5. Command confirms domain mapping to server.

⊞Administrator: Windows 11 Command Prompt (cmd.exe)

>nslookup nextsem.online

⊞Windows 11 Execution OutputReal PC Match

Microsoft Windows [Version 10.0.22631.3007] (Windows 11 Pro x86_64)

C:\Users\Student> nslookup nextsem.online Execution successful! Output verified on Windows 11 Pro x86_64.

4. Understanding DNS Record Types

1. A records map domains to IPv4.

2. AAAA records map domains to IPv6.

3. CNAME records create domain address aliases.

4. MX records direct domain email traffic.

5. TXT records store domain verification data.