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Practical

Practical 4: Basic LAN with Static IP Addresses

Build a 4-PC LAN, assign static IPs, and test connectivity

🌐 Introduction to Networks 🛠️ Packet Tracer 👤 Reza Farashahi
In this practical you will create a basic Local Area Network with 4 PCs connected through a switch. You will assign static IP addresses to each PC, verify the configuration with ipconfig, and test connectivity using ping.

📋 Requirements

📦 Task 1 — Create the Network Topology

  1. Open Packet Tracer and create a new file.
  2. From the device panel add:
    • End Devices → 4 × PC
    • Network Devices → 1 × 2960 Switch
  3. Arrange the switch centrally with the PCs around it (star layout).
  4. Select Copper Straight-Through from Connections and cable each PC to the switch:
    • PC1 (FastEthernet0) → Switch (e.g. FastEthernet0/1)
    • PC2 (FastEthernet0) → Switch (e.g. FastEthernet0/2)
    • PC3 (FastEthernet0) → Switch (e.g. FastEthernet0/3)
    • PC4 (FastEthernet0) → Switch (e.g. FastEthernet0/4)
Tip: Place the switch in the centre with PCs around it to keep the diagram clean.

🔢 Task 2 — Assign IP Addresses

Use the 192.168.100.0/24 network with the following scheme:

Device IP Address Subnet Mask
PC1 192.168.100.10 255.255.255.0 (/24)
PC2 192.168.100.20 255.255.255.0 (/24)
PC3 192.168.100.30 255.255.255.0 (/24)
PC4 192.168.100.40 255.255.255.0 (/24)

Configure each PC

Repeat for every PC (using its address from the table above):

  1. Click on the PC.
  2. Go to the Desktop tab → IP Configuration.
  3. Enter the IPv4 Address and Subnet Mask.
  4. Leave Default Gateway blank (no router in this topology).
  5. Close the window.
Tip: You can also set the IP via Config tab → FastEthernet0. Both methods work the same way.

🔍 Task 3 — Verify IP Configuration

On each PC, open the Command Prompt (Desktop tab) and run:

  1. Type ipconfig and press Enter.
  2. Confirm the IP address and subnet mask match the table above.
Tip: Use ipconfig /all for more detail, including the MAC address of the interface.

📡 Task 4 — Test Connectivity

Now test that every PC can reach the others using ping.

Ping tests

  1. PC1 → PC2: on PC1 run ping 192.168.100.20
  2. PC2 → PC3: on PC2 run ping 192.168.100.30
  3. PC3 → PC4: on PC3 run ping 192.168.100.40
  4. PC4 → PC1: on PC4 run ping 192.168.100.10

You should see successful replies for each test.

Troubleshooting: If a ping fails, double-check the IP settings on both PCs and make sure the cable connection to the switch shows green lights.

🎬 Task 5 — Simulation Mode (Optional)

Use Simulation mode to visualise how data travels through the network.

  1. Click the Simulation button (bottom-right corner).
  2. Click Add Simple PDU.
  3. Click on a source PC (e.g. PC1), then click on the destination (e.g. PC4).
  4. Press Auto Capture / Play to watch the packet traverse the switch.
Observe: The first time the switch receives a frame it floods all ports (unknown MAC). After learning the MAC addresses it forwards only to the correct port.

🔢 Task 6 — Binary ↔ Decimal Conversion Practice

IP addresses are made up of 4 octets, each stored as an 8-bit binary number. Practise converting between decimal and binary for the values used in this practical.

Decimal → Binary: Divide the number by 2 repeatedly. The remainders, read bottom to top, give the binary result.
Binary → Decimal: Multiply each bit by its place value (2⁷=128, 2⁶=64, 2⁵=32, 2⁴=16, 2³=8, 2²=4, 2¹=2, 2⁰=1) and add them up.

Part A — Decimal → Binary

Convert each decimal number to an 8-bit binary number (e.g. 11000000).

DecimalYour Answer (binary)
192
168
100
10
255

Part B — Binary → Decimal

Convert each 8-bit binary number to its decimal value.

BinaryYour Answer (decimal)
10101000
00001010
11111111
01100100
11000000

📝 Summary

In this practical you have:

Tip: Save your Packet Tracer file — future practicals will build on this network.