🌐 DNS Troubleshooting

📖 What is DNS?

DNS (Domain Name System) என்பது Domain Name-ஐ IP Address-ஆக மாற்றும் Internet Service ஆகும்.

🎯 Why DNS is Important?

✔ Website Access

✔ Email Services

✔ Internet Browsing

✔ Application Connectivity

✔ Domain Resolution

⚙ How DNS Works?

User google.com என Type செய்தால் DNS Server அதற்கான IP Address-ஐ கண்டுபிடித்து வழங்குகிறது.

பிறகு Browser அந்த IP Address-ஐ பயன்படுத்தி Website-ஐ திறக்கிறது.

💻 DNS Commands

nslookup google.com

nslookup openai.com

ipconfig /flushdns

ipconfig /displaydns

🚨 Common DNS Problems

DNS Server Not Responding

Name Resolution Failure

Incorrect DNS Configuration

DNS Cache Issues

Slow Website Access

🔧 Troubleshooting Steps

✔ Verify DNS Server IP

✔ Run nslookup Test

✔ Flush DNS Cache

✔ Test Internet Connectivity

✔ Change Alternate DNS Server

📊 Popular DNS Servers

Google DNS : 8.8.8.8

Google DNS : 8.8.4.4

Cloudflare DNS : 1.1.1.1

Cloudflare DNS : 1.0.0.1

🌍 Real World Usage

Enterprise Networks

Data Centers

ISP Networks

Cloud Platforms

Internet Services

🎤 Interview Questions

What is DNS?

What is nslookup?

What is DNS Cache?

How to Troubleshoot DNS Issues?

Difference Between DNS and DHCP?

📝 Summary

DNS Troubleshooting என்பது Website Access மற்றும் Internet Connectivity பிரச்சினைகளை சரிசெய்ய மிகவும் முக்கியமான Skill ஆகும்.

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