Networking Fundamentals with OS

ByMd Rayyan Nawaz -
0

Understanding IP Addressing, Subnetting, and Routing in Windows and Linux Environments

Introduction

Imagine the internet as a vast city where every device (like computers, smartphones, and printers) is a house. To send a letter (data) to the right house, you need an address. In networking, this address is called an IP address. This guide will explain IP addressing, subnetting, and routing in simple terms and show you how they work in both Windows and Linux environments.

1. IP Addressing

What is an IP Address?

An IP address (Internet Protocol address) is a unique number assigned to every device connected to a network. It allows devices to identify and communicate with each other.

  • Example of an IPv4 address: 192.168.1.10
  • Example of an IPv6 address: 2001:0db8:85a3:0000:0000:8a2e:0370:7334

Types of IP Addresses

  1. IPv4 (Internet Protocol version 4)

    • Uses 32-bit addresses.
    • Format: Four numbers separated by periods (e.g., 192.168.1.1).
    • Limited to about 4.3 billion addresses.

  2. IPv6 (Internet Protocol version 6)

    • Uses 128-bit addresses.
    • Format: Eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).
    • Provides a virtually limitless number of addresses.

Purpose of IP Addresses

  • Identification: Distinguish one device from another on a network.
  • Location Addressing: Determine where a device is located in the network.

2. Subnetting

What is Subnetting?

Subnetting is the process of dividing a large network into smaller, more manageable pieces called subnets. Think of it as dividing a large neighborhood into smaller blocks to make mail delivery more efficient.

Why Subnet?

  • Efficient IP Address Utilization: Prevents wasting IP addresses.
  • Improved Network Performance: Reduces congestion by limiting broadcast traffic to smaller subnets.
  • Enhanced Security: Isolates network segments to contain potential breaches.

How Subnetting Works

An IP address consists of two parts:

  1. Network Portion: Identifies the network.
  2. Host Portion: Identifies the specific device on the network.

A subnet mask determines where the network portion ends and the host portion begins.

  • Subnet Mask Example: 255.255.255.0 or /24 in CIDR notation.

Subnet Mask Explained

  • 255 indicates that all bits in that octet are part of the network portion.
  • 0 indicates that all bits in that octet are part of the host portion.

CIDR Notation

Classless Inter-Domain Routing (CIDR) notation represents the subnet mask by the number of bits used for the network portion.

  • Example: 192.168.1.0/24 means the first 24 bits are the network portion.

Subnetting Example

  • Original Network: 192.168.1.0/24 (256 IP addresses).
  • Goal: Create two subnets.
  • Process:
    • Borrow 1 bit from the host portion.
    • New subnet mask: /25 (255.255.255.128).
  • Resulting Subnets:
    • Subnet 1: 192.168.1.0 - 192.168.1.127
    • Subnet 2: 192.168.1.128 - 192.168.1.255

3. Routing

What is Routing?

Routing is the process of moving data packets from one network to another. Routers act like postal sorters, directing data along the most efficient paths to reach their destinations.

How Routing Works

  1. Data Packets: Information is broken into packets for transmission.
  2. Routers: Devices that forward packets between networks.
  3. Routing Tables: Routers use these tables to decide where to send packets next.

Types of Routing

  1. Static Routing: Routes are manually configured.
  2. Dynamic Routing: Routes are automatically adjusted using routing protocols (e.g., OSPF, RIP).

4. Windows Networking Environment

Configuring IP Addresses in Windows

Using the Graphical User Interface (GUI)

  1. Open Network Connections:

    • Go to Control Panel > Network and Internet > Network and Sharing Center.
    • Click on Change adapter settings.

  2. Access Adapter Properties:

    • Right-click your network adapter (e.g., Ethernet or Wi-Fi) and select Properties.

  3. Set IP Address:

    • Select Internet Protocol Version 4 (TCP/IPv4) and click Properties.
    • Choose Use the following IP address and enter:
      • IP address: Your desired IP (e.g., 192.168.1.10).
      • Subnet mask: Corresponding mask (e.g., 255.255.255.0).
      • Default gateway: Your router's IP (e.g., 192.168.1.1).
    • Click OK to apply.

Using Command Prompt

  1. View Current Configuration:

    • Open Command Prompt and type ipconfig.

  2. Set a Static IP Address:

    • Use the netsh command:
      netsh interface ip set address name="Ethernet" static IP_ADDRESS SUBNET_MASK GATEWAY
      • Replace Ethernet with your adapter name.
      • Example:
        netsh interface ip set address name="Ethernet" static 192.168.1.10 255.255.255.0 192.168.1.1

Viewing the Routing Table in Windows

  • Command: route print
  • This displays the routing table, showing how your computer routes data.

5. Linux Networking Environment

Configuring IP Addresses in Linux

Using the Terminal

  1. View Current Configuration:

    • Type ip addr show or ifconfig (if installed).

  2. Set a Static IP Address:

    • Using ip command (modern systems):

      sudo ip addr add IP_ADDRESS/SUBNET_MASK dev INTERFACE
      • Example:
        sudo ip addr add 192.168.1.10/24 dev eth0
      • To set the default gateway:
        sudo ip route add default via GATEWAY_IP
        • Example:
          sudo ip route add default via 192.168.1.1

    • Using ifconfig command (older systems):

      sudo ifconfig INTERFACE IP_ADDRESS netmask SUBNET_MASK
      • Example:
        sudo ifconfig eth0 192.168.1.10 netmask 255.255.255.0

Persisting Configuration

To make the IP configuration permanent, you need to edit network configuration files, which vary depending on the Linux distribution (e.g., /etc/network/interfaces for Debian/Ubuntu or /etc/sysconfig/network-scripts/ifcfg-eth0 for CentOS/Red Hat).

Viewing the Routing Table in Linux

  • Command: ip route show or route -n
  • This displays the routing table, similar to Windows.

6. Practical Examples

Example 1: Configuring a Static IP in Windows

  1. Scenario: Assign 192.168.1.50 to your Windows PC with a subnet mask of 255.255.255.0 and gateway 192.168.1.1.

  2. Steps:

    • Open Command Prompt as Administrator.
    • Run:
      netsh interface ip set address name="Ethernet" static 192.168.1.50 255.255.255.0 192.168.1.1

Example 2: Configuring a Static IP in Linux

  1. Scenario: Assign 192.168.1.50 to your Linux PC with a subnet mask of 24 and gateway 192.168.1.1.

  2. Steps:

    • Open Terminal.
    • Run:
      sudo ip addr add 192.168.1.50/24 dev eth0
sudo ip route add default via 192.168.1.1

7. Additional Concepts

Public vs. Private IP Addresses

  • Private IP Addresses: Used within a private network (e.g., 192.168.x.x, 10.x.x.x).
  • Public IP Addresses: Assigned to devices accessible over the internet.

NAT (Network Address Translation)

  • Allows multiple devices on a private network to share a single public IP address.

DHCP (Dynamic Host Configuration Protocol)

  • Automatically assigns IP addresses to devices on a network.
  • Reduces the need for manual configuration.

8. Summary

  • IP Addressing: Assigns unique identifiers to devices for communication.
  • Subnetting: Divides networks into smaller sub-networks for efficiency and security.
  • Routing: Directs data packets between networks using routers.
  • Windows and Linux: Both systems provide tools to configure and manage networking settings.

9. Useful Commands Reference

Windows Commands

  • View IP Configuration: ipconfig
  • View Routing Table: route print
  • Set Static IP:
    netsh interface ip set address name="ADAPTER_NAME" static IP_ADDRESS SUBNET_MASK GATEWAY
  • Flush DNS Cache: ipconfig /flushdns

Linux Commands

  • View IP Configuration: ip addr show or ifconfig
  • View Routing Table: ip route show or route -n
  • Set Static IP (temporary):
    sudo ip addr add IP_ADDRESS/SUBNET_MASK dev INTERFACE
sudo ip route add default via GATEWAY_IP
  • Restart Network Service (varies by distribution):
    • Debian/Ubuntu: sudo systemctl restart networking
    • CentOS/Red Hat: sudo systemctl restart network

10. Final Tips

  • Documentation: Always refer to the official documentation for your operating system.
  • Backup Configurations: Before making changes, back up existing configurations.
  • Security: Ensure that your network settings comply with your organization's security policies.
  • Practice: Set up a small network in a virtual environment to practice configuring IP addresses, subnetting, and routing.

By understanding these core networking concepts, you'll be better equipped to manage and troubleshoot network issues in both Windows and Linux environments.

Tags
Premium By Raushan Design With Shroff Templates

You may like these posts

Post a Comment

Previous Post Next Post