Linux Networking and Firewall Configuration on Azure

Understanding Linux networking and firewall configuration is essential for securing and maintaining servers in any cloud or on-premises environment. In this lab, you will connect via lab Code-IDE to a pre-provisioned Ubuntu Server virtual machine running on Azure and perform hands-on network configuration and security hardening tasks. You will inspect and configure network interfaces using ip, nmcli, and netplan, create host-based firewall rules with both iptables and ufw, harden the SSH server to restrict unauthorized access, manage local hostname resolution through /etc/hosts, and diagnose connectivity issues using standard Linux networking tools. These skills align directly with the BCIT ACIT 2420 curriculum and prepare you for real-world network administration responsibilities.

Objectives

Upon completing this intermediate level lab, you will be able to:

• Inspect and configure network interfaces using ip addr, nmcli, and netplan YAML configuration files
• Create and manage firewall rules using both iptables and ufw for host-based packet filtering
• Harden an SSH server configuration by disabling root login, enforcing key-based authentication, and restricting access
• Diagnose network connectivity and DNS resolution issues using ping, traceroute, ss, dig, and nslookup
• Manage local hostname resolution by editing /etc/hosts and verify DNS behavior with query tools

Who is this lab for?

This lab is designed for:

• Linux system administration students studying networking fundamentals, particularly those enrolled in BCIT ACIT 2420 or equivalent courses
• Junior system administrators who want hands-on experience configuring firewalls and hardening SSH on Linux servers
• DevOps engineers looking to deepen their understanding of Linux network configuration and security in cloud-hosted environments