Netlab Demo Project

This project sets up a multi-layer network lab using Netlab tool (Containerlab), demonstrating a robust and redundant network architecture. It includes core, distribution, access, and host layers, configured with VLANs, VRRP for gateway redundancy, and OSPF routing.

Table of Contents

• Netlab Demo Project
  • Table of Contents
  • Project Overview
  • Prerequisites
  • Setup Instructions
  • Network Topology
  • Verification Steps
  • Troubleshooting Tips
  • Cleanup

Project Overview

This Containerlab-based network lab simulates a typical enterprise network design. It features:

• Core Layer: A single router (R1) responsible for external connectivity (if extended).
• Distribution Layer: Two Layer 3 switches (D1, D2) providing routing and switching functions, including Integrated Routing and Bridging (IRB) for VLAN interfaces and VRRP for gateway redundancy.
• Access Layer: Two Layer 2 switches (S1, S2) connecting end-user devices (hosts) to the network.
• Host Layer: Four Linux hosts (H1, H2, H3, H4) connected to the access layer switches.

The lab utilizes Cisco IOL images for network devices and Alpine Linux for hosts. Ansible is used for configuration management, with Jinja2 templates generating device-specific configurations.

Prerequisites

To deploy and run this lab, you need the following installed on your system:

• Containerlab: A tool for orchestrating and managing container-based networking labs.
  • Installation Guide
• Docker: Containerization platform used by Containerlab.
  • Installation Guide
• Ansible: For configuration management (though configurations are pre-generated in this demo).
  • Installation Guide
• Netlab Tool A virtual networking labbing tool
  • Installation Guide

Setup Instructions

1. Clone the Repository:

   git clone https://github.com/sydasif/netlab-demo.git
   cd netlab-demo

2. Deploy the Lab:

   netlab up

   This command will create and start all the network devices and hosts defined in topology.yml.

3. Access Devices: You can access the devices via SSH. Containerlab will provide connection details after deployment. For example, to access R1:

   netlab connect R1

Network Topology

The lab consists of the following nodes and their roles:

• R1 (Core Router): Cisco IOL router.
• D1, D2 (Distribution Switches): Cisco IOL L2 switches with IRB.
• S1, S2 (Access Switches): Cisco IOL L2 switches.
• H1, H2, H3, H4 (Hosts): Alpine Linux containers.

VLANs and IP Addressing:

• VLAN 10: Network 172.16.0.0/24
  • Gateway: 172.16.0.254 (VRRP virtual IP)
  • Hosts: H1 (172.16.0.6), H4 (172.16.0.9)
• VLAN 20: Network 172.16.1.0/24
  • Gateway: 172.16.1.254 (VRRP virtual IP)
  • Hosts: H2 (172.16.1.7), H3 (172.16.1.8)
• Point-to-Point Links: 10.1.0.0/16
• Loopbacks: 10.0.0.0/24
• Management Network: 192.168.121.0/24

VRRP Configuration:

• VLAN 10 Gateway (172.16.0.254):
  • D1: VRRP priority 110 (Primary)
  • D2: VRRP priority 100 (Backup)
• VLAN 20 Gateway (172.16.1.254):
  • D1: VRRP priority 100 (Backup)
  • D2: VRRP priority 110 (Primary)

All IP addressing are built-in. See Using Built-In Address Pools

Verification Steps

After deploying the lab, you can verify its functionality:

1. Check VRRP Status: Log in to D1 and D2 and check the VRRP status for VLAN 10 and VLAN 20 interfaces.

   # On D1 or D2
   show vrrp brief

   You should see D1 as Master for VLAN 10 and D2 as Master for VLAN 20.

2. Ping between Hosts in the Same VLAN: Ping from H1 to H4 (VLAN 10) and from H2 to H3 (VLAN 20).

   # On H1
   ping 172.16.0.9
   
   # On H2
   ping 172.16.1.8

3. Ping between Hosts in Different VLANs: Ping from H1 (VLAN 10) to H2 (VLAN 20). This traffic should be routed via the VRRP gateways on D1/D2 and then through R1.

   # On H1
   ping 172.16.1.7

4. Check OSPF Neighbors: Log in to R1, D1, and D2 to verify OSPF neighbor relationships.

   # On R1, D1, or D2
   show ip ospf neighbor

Troubleshooting Tips

• Containerlab Issues: If containers fail to start, check the clab deploy output for errors. Ensure Docker is running and Containerlab is correctly installed.

Cleanup

To destroy the lab and remove all containers:

netlab down --cleanup