Basic Network Topology & Configuration with GNS3

Overview

This project demonstrates a basic network design and configuration using Cisco IOSv in GNS3. The setup includes configuring IP addressing, static routing, VLANs, and Inter-VLAN routing in a simulated environment. This will help us understand and implement fundamental networking concepts using GNS3 in a Virtualized Environment.

Objectives

• Design and configure a small network topology with 3 Ubuntu docker containers, 2 Switches and a single Router.
• Implement basic IP addressing and subnetting.

Utilities used

• GNS3
• HyperV (For GNS3-VM)
• Cisco IOSv
• PuTTY

Network Topology

The network consists of:

2 Ubuntu Docker Container

• Ubuntu-Docker-1
• Ubuntu-Docker-2
• Ubuntu-Docker-3

2 Switches

• Switch-1
• Switch-2

1 Router

• Router

IP Addressing Scheme

• Ubuntu-Docker-1: 192.168.1.2/24 (Interface connected to Switch1)
• Ubuntu-Docker-2: 192.168.2.2/24 (Interface connected to Switch2)
• Ubuntu-Docker-3: 192.168.2.3/24 (Interface connected to Switch2)
• Router G0/0 (192.168.1.1) G0/1 (192.168.2.1)

Process

Step 1: Create a new project

Open GNS3 and create a new project by going to File -> New Project

Step 2: Design the Network Topology

• Add Devices: For a basic setup, we use 3 Ubuntu Docker containers, 2 Switches and 1 Router

• Connect Devices:

Step 3: Assigning Static IP address

• Open console for Router

enable
conf t
int g0/0
ip address 192.168.1.1 255.255.255.0
int g0/1
ip address 192.168.2.1 255.255.255.0
no shut
end
wr

• Open console for Ubuntu-Docker-1

ip addr add 192.168.1.2/24 dev eth0
ip link set dev eth0 up
route add default gw 192.168.1.1 dev eth0

• Open console for Ubuntu-Docker-2

ip addr add 192.168.2.2/24 dev eth0
ip link set dev eth0 up
route add default gw 192.168.0.1 dev eth0

• Open console for Ubuntu-Docker-3

ip addr add 192.168.2.3/24 dev eth0
ip link set dev eth0 up
route add default gw 192.168.2.1 dev eth0

Step 4: Testing Connectivity

From Ubuntu-Docker-1 to Ubuntu-Docker-3

ping 192.168.2.3

Output: