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Practice Exercise: Subnetting a Class A IP Address

Introduction

In this lab, you will learn how to subnet a Class A IP address, which is essential for network administrators managing large networks. You'll step into the role of a network administrator tasked with dividing a Class A IP address space efficiently. This skill is crucial for managing complex network infrastructures.

Prerequisites

  • Basic knowledge of IP addresses and binary conversion
  • A pen and paper or calculator for manual calculations

Lab Scenario

You are responsible for designing the network infrastructure of a large organization called "GlobalTech Inc." GlobalTech has been allocated a Class A IP address block (10.0.0.0/8) and requires a structured subnetting plan to accommodate various departments and locations across the globe. Solutions are provided at the end of the document, but make sure to understand each tasks.

Tasks

Task 1: Determine Requirements

  • Gather information about GlobalTech's network requirements. How many subnets are needed? What is the size of each subnet?
  • Calculate the total number of subnets required to meet these needs.

Task 2: Choose Subnet Mask

  • Select an appropriate subnet mask based on the number of required subnets and hosts per subnet.
  • Calculate the subnet mask in both dotted-decimal and binary notation.

Task 3: Determine Subnet Size

  • Calculate the number of bits required for the subnet portion of the IP address.
  • Determine the size of each subnet in terms of the number of host addresses.

Task 4: Create Subnet Table

  • Create a subnet table that includes the network address, usable IP address range, and broadcast address for each subnet.
  • Calculate these values for each subnet.

Task 5: Assign Subnets

  • Assign subnets to different departments or geographical locations within GlobalTech.
  • Ensure that each subnet has its own unique range of IP addresses.

Task 6: Troubleshoot Subnet Configuration

  • Simulate an incorrect subnet configuration by assigning overlapping IP address ranges to different subnets.
  • Identify the conflict and troubleshoot it by reconfiguring the subnets correctly.

Task 7: Verify Subnet Connectivity

  • Configure devices within the same subnet (e.g., subnet 1).
  • Use the ping command to verify connectivity between the devices.
  • Ensure that they can communicate successfully.

Task 8: Calculate Available Hosts

  • Determine the number of available host addresses in each subnet.
  • Calculate the broadcast address for each subnet.

Task 9: Troubleshoot Subnet Size

  • Simulate a scenario where the subnet size is too small to accommodate the required number of hosts.
  • Troubleshoot the issue and adjust the subnet size accordingly.

Task 10: Reallocation of Subnets

  • Modify the subnetting scheme to allocate more IP addresses to a specific department or location that is expanding.
  • Update the subnet table and configuration accordingly.

Sample Troubleshooting Command

  • Simulate an incorrect subnet configuration by assigning overlapping IP address ranges to different subnets.
  • Use the subnet table to identify and troubleshoot the conflict.

Solutions

Task 1: Determine Requirements

  • GlobalTech Inc. requires 16 subnets to accommodate different departments and locations.

Task 2: Choose Subnet Mask

  • Based on 16 subnets, a subnet mask of /28 is chosen (255.255.255.240 in dotted-decimal notation).
  • In binary notation, the subnet mask is 11111111.11111111.11111111.11110000.

Task 3: Determine Subnet Size

  • 4 bits are required for subnetting (2^4 = 16).
  • Each subnet can accommodate 14 host addresses.

Task 4: Create Subnet Table

  • Subnet 1: Network Address: 10.0.0.0, Usable Range: 10.0.0.1 to 10.0.0.14, Broadcast Address: 10.0.0.15
  • Subnet 2: Network Address: 10.0.0.16, Usable Range: 10.0.0.17 to 10.0.0.30, Broadcast Address: 10.0.0.31
  • (Repeat for all 16 subnets)

Task 5: Assign Subnets

  • Subnet 1: Headquarters
  • Subnet 2: Sales Department
  • (Assign departments or locations to subnets as needed)

Task 6: Troubleshooting Subnet Configuration

  • Identify the conflict in subnet 2 and resolve it by adjusting the IP address range.

Task 7: Verify Subnet Connectivity

  • Devices within the same subnet (e.g., subnet 1) can successfully communicate.

Task 8: Calculate Available Hosts

  • Each subnet has 14 available host addresses.
  • Broadcast address for subnet 1: 10.0.0.15

Task 9: Troubleshoot Subnet Size

  • Increase the subnet size to /27 (32 IP addresses) for the expanding department.

Task 10: Reallocation of Subnets

  • Reallocate IP addresses to the expanding department's subnet.
  • Update the subnet table and configuration accordingly.

These exercises will help you understand the process of subnetting a Class A IP address and its practical applications in network management.