Lab 08 - Wireless Networks & NAT

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Lab Objective

Introduction to Wireless Networks and Network Address Translation (NAT). Learn to configure wireless networks in Packet Tracer and implement different types of NAT for network connectivity and security.

1. Wireless Network

1.1 Introduction

A wireless network allows devices to connect without physical cables. Devices communicate using Radio Frequency (RF) signals via Access Points (APs).

  • AP broadcasts Wi-Fi signals
  • Devices use wireless adapters (built-in or USB) to connect
  • Common example: Wi-Fi in cafés, universities, offices

Difference from Wired Network

Wired Wireless
Needs cables No cables
Less mobility High mobility
Setup cost higher Setup cost lower
Stable connection Can face interference

1.2 Importance of Wireless Technology

  • Mobility: Move freely while staying connected
  • Flexibility: Easy installation, no cabling needed
  • Reduced Cost: Less hardware needed
  • Scalability: Easily add more devices

1.3 Working of Wireless Network

WLAN works similar to LAN but with RF waves. AP sends wireless signals; PCs detect and join using SSID. AP often connects to wired network → provides Internet.

1.4 Configuration of Wireless Network (Packet Tracer)

Topology uses Linksys Wireless Router + 6 PCs.

Default Router Settings:

  • DHCP: Enabled
  • DHCP Pool: 192.168.0.100 – 192.168.0.150
  • Router IP: 192.168.0.1
  • SSID: Default
  • Security: None

Tasks Performed

  • Change SSID
  • Disable DHCP
  • Change Router IP
  • Assign Static IPs
  • Configure WEP Security
  • Connect PCs using WEP key

Configuration Steps

Step 1 — Login to Router

Go to browser → 192.168.0.1

Username: admin | Password: admin

Step 2 — Disable DHCP

Setup → DHCP → Disable → Save

Step 3 — Change Password

Administration → Password → test

Step 4 — Change SSID

Wireless → Basic Wireless → Set SSID = FastNetwork

Step 5 — Configure WEP Security

Wireless → Wireless Security → Security Mode = WEP → Key = 0123456789

Step 6 — Set Static IPs for PCs

PC IP Mask Gateway
1 192.168.0.2 255.255.255.0 192.168.0.1
2 192.168.0.4 255.255.255.0 192.168.0.1
3 192.168.0.5 255.255.255.0 192.168.0.1
4 192.168.0.6 255.255.255.0 192.168.0.1
5 192.168.0.7 255.255.255.0 192.168.0.1
6 192.168.0.8 255.255.255.0 192.168.0.1

Step 7 — Connect PC to Wi-Fi

Desktop → PC Wireless → Refresh → Select FastNetwork → Enter WEP key → Connect

2. NAT (Network Address Translation)

2.1 What is NAT?

NAT maps private IPs ↔ public IPs.

Why NAT?

  • Save IPv4 addresses
  • Allow many devices to share 1 public IP
  • Provides basic protection

(NOTE: NAT ≠ Firewall)

2.2 Types of NAT

1. Static NAT

One private IP ↔ One public IP

Used for: Servers needing public access (Example: Web server)

ip nat inside source static 192.168.0.10 209.165.200.10

2. Dynamic NAT

Many private IPs map to pool of public IPs

One-to-one mapping but public IP varies

ip nat pool MYPOOL 209.165.200.226 209.165.200.240 netmask 255.255.255.224
access-list 1 permit 192.168.0.0 0.0.0.255
ip nat inside source list 1 pool MYPOOL

3. PAT (NAT Overload)

Many private IPs share one public IP

Uses different port numbers

Most common in homes/offices

access-list 1 permit 192.168.0.0 0.0.0.255
ip nat inside source list 1 interface serial 0/0/0 overload

3. NAT Configuration Example

Karachi Router (R1) – PAT

Interfaces:

  • Fa0/0 → 192.168.1.1
  • S2/0 → 192.168.2.1
access-list 1 permit 192.168.1.2 0.0.0.0
access-list 1 permit 192.168.1.3 0.0.0.0
ip nat pool ccna 50.0.0.1 50.0.0.1 netmask 255.0.0.0
ip nat inside source list 1 pool ccna overload
interface fa0/0
 ip nat inside
interface s0/0/0
 ip nat outside

Lahore Router (R2) – Static NAT

Interfaces:

  • Fa0/0 → 192.168.3.1
  • S2/0 → 192.168.2.2
ip nat inside source static 192.168.3.1 200.0.0.10

Routing Configuration

R1 Static Route

ip route 200.0.0.0 255.255.255.0 100.0.0.2

R2 Static Route

ip route 50.0.0.0 255.0.0.0 100.0.0.1

4. Verification Commands

NAT Verification Commands

show ip nat translations
Check NAT translations
show ip nat statistics
Check NAT statistics
show ip interface brief
Check interfaces
ping <IP>
Ping test

Flowchart Summary

Static NAT

One-to-one mapping

For servers

Dynamic NAT

Pool-based mapping

Many-to-many

PAT

Port-based mapping

Many-to-one

Wireless

RF communication

No cables needed

Lab Resources

Wireless Networks & NAT Guide

Download PDF