IP Addressing and DNS: Basics for JKSSB Exams
The Internet and computer networks work using two main concepts: IP Addressing and DNS (Domain Name System). For the JKSSB Computer Awareness section, understanding these topics is essential.
This guide will explain:
- What is an IP Address?
- Types of IP Addresses
- What is DNS?
- How DNS works
- Examples and FAQs for JKSSB
What is an IP Address?
An IP Address is like the home address of a device on the internet. It helps devices identify and communicate with each other.
IP stands for: Internet Protocol
Simple Example:
- Your computer has an IP address like 192.168.1.5
- Just like your house has a unique postal address, your device has a unique IP
Types of IP Addresses
IP addresses are mainly of two types:
1️⃣ IPv4 (Internet Protocol Version 4)
- Most common IP address type
- Format: 4 numbers separated by dots
- Example: 192.168.0.1
- Range: 0.0.0.0 to 255.255.255.255
- Each number is called an octet
- Total addresses: 4.3 billion (but many are reserved)
2️⃣ IPv6 (Internet Protocol Version 6)
- Newer version due to shortage of IPv4 addresses
- Format: 8 groups of 4 hexadecimal digits
- Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334
- Almost unlimited number of IPs (340 undecillion)
Static vs Dynamic IP Address
| Type | Description |
|---|---|
| Static IP | Permanent IP address assigned to a device |
| Dynamic IP | Temporary IP assigned by servers, changes every time |
Public vs Private IP Address
| Type | Description |
|---|---|
| Public IP | Used on the Internet; unique across the world |
| Private IP | Used within a local network (LAN/Wi-Fi) |
Examples of Private IP Ranges:
- 192.168.x.x
- 10.x.x.x
- 172.16.x.x to 172.31.x.x
What is DNS?
DNS (Domain Name System) works like a phonebook of the Internet.
Humans remember domain names like www.google.com, but computers understand IP addresses.
DNS converts domain names into IP addresses.
Example:
- When you type www.facebook.com in a browser, DNS translates it into the IP address of Facebook’s server.
- You don’t have to remember long IP addresses, DNS does it for you.
How Does DNS Work?
The process of converting a domain name to an IP is called DNS Resolution.
- User types www.example.com
- The request goes to a DNS Resolver
- Resolver asks the Root Server
- Root Server directs to the Top-Level Domain (TLD) Server (.com, .org, etc.)
- TLD Server points to the Authoritative DNS Server
- Authoritative Server returns the IP address
- Browser connects to that IP to load the website
Structure of DNS
- Root Level: Represented by a dot "." (invisible)
- Top Level Domain (TLD): .com, .in, .org, etc.
- Second Level Domain: google, facebook, etc.
- Subdomain: mail.google.com, blog.example.com
Common DNS Terms
- DNS Server: A computer that stores domain name to IP mappings
- DNS Resolver: Takes the user query and starts the resolution process
- Authoritative Server: Has final information about domain IPs
- Cache: Saves recent DNS lookups to speed up future queries
Advantages of DNS
- Users can remember names instead of numbers
- Makes the Internet user-friendly
- Provides redundancy (multiple DNS servers for safety)
- Allows websites to change IP addresses without changing domain names
DNS Server Examples
| Provider | DNS Address |
|---|---|
| Google DNS | 8.8.8.8 and 8.8.4.4 |
| Cloudflare DNS | 1.1.1.1 |
| OpenDNS | 208.67.222.222 |
IP Address and DNS in Daily Life
- When you browse the internet, DNS helps you connect to websites
- IP addresses help devices identify each other
- Email services use IP and DNS to route emails
Security Issues Related to DNS
- DNS Spoofing: Fake DNS responses redirect users to wrong websites
- DDoS Attacks: Hackers target DNS servers to block internet access
- DNS Hijacking: Changing DNS settings to divert traffic
Ways to Secure DNS
- Use secure DNS services (like Cloudflare DNS)
- Enable DNS over HTTPS (DoH)
- Regularly update DNS servers
FAQs: IP Address and DNS – JKSSB
Q1: What is the full form of IP?
Answer: Internet Protocol
Q2: What does DNS stand for?
Answer: Domain Name System
Q3: Give an example of IPv4 address.
Answer: 192.168.1.1
Q4: Why do we need DNS?
Answer: To convert website names into IP addresses
Q5: What is a public IP?
Answer: An IP address that is visible on the Internet
Final Thoughts
IP Addressing and DNS are the backbone of the Internet. For the JKSSB Computer Awareness section, understanding these concepts will help you answer exam questions easily.
Remember the basics, examples, and FAQs to prepare well for your exam.
All the best for your JKSSB preparation!
