Chapter 04: Networking Fundamentals (netplan-First)

Word target: 3,500
Primary deliverable: IP plan, DNS plan, and routing policy
Key diagrams: Subnet map, DNS flow, ingress/egress boundaries

Learning Goals

  • Build a clean internal addressing strategy.
  • Apply Ubuntu netplan patterns for static and DHCP deployments.
  • Validate routing, DNS, and firewall behavior with repeatable tests.

MVP Lab Worksheet

  • Objective: Implement base network plan.
  • Starting state: One Proxmox VM + Azure VPS.
  • Steps:
    1. Define subnet/IP/hostname conventions.
    2. Configure netplan on VM and VPS.
    3. Validate DNS resolution and connectivity paths.
  • Evidence: Netplan configs + test logs.
  • Exit criteria: Stable L3 and name resolution.
  • Rollback: Restore previous netplan file and apply.

Advanced Lab Worksheet

  • Objective: Add segmented network zones.
  • Starting state: Base network operational.
  • Steps:
    1. Define trusted, app, and management segments.
    2. Add policy restrictions between zones.
    3. Run connectivity and denied-path tests.
  • Evidence: Policy matrix + test evidence.
  • Exit criteria: Segmentation enforced and documented.
  • Rollback: Return to flat network policy.
Author Gap Check

Add a section explaining common netplan failure recovery from console access.