Skip to content

🛠 Project 01 — VLSM Network Design

Network Systems

View the live site — ijk37.com

Project 01: VLSM Network Design

Home All Projects Notes Quiz

Type: Design document + Packet Tracer verification Modules: 03 (Addressing), 08 (Subnets & VLANs) Difficulty: ⭐⭐⭐

🎯 Objective

Design a complete, efficient IPv4 addressing plan for a multi-department company using Variable Length Subnet Masking (VLSM), then verify it in Packet Tracer.

🧭 Scenario

Acme Corp has been assigned the block 172.16.0.0/22. You must subnet it for the following requirements (largest first):

Department Hosts needed
Sales 250
Engineering 120
Support 60
Management 25
Servers (DMZ) 12
WAN link R1–R2 2
WAN link R2–R3 2

📌 Requirements

  1. Use VLSM — size each subnet to its need, no wasted space.
  2. Allocate largest requirement first.
  3. No overlapping subnets.
  4. Document, for each subnet: network ID, mask (CIDR + dotted decimal), usable host range, and broadcast address.
  5. Reserve the first usable address of each LAN subnet for the gateway.

🧩 Tasks

🔹 Part A — Design (on paper / in the design doc)

  1. For each requirement, find the smallest prefix that fits (2^h − 2 ≥ hosts).
  2. Starting at 172.16.0.0, allocate subnets in descending size order, incrementing by each block size.
  3. Fill in the addressing table (template in design.md).

🔹 Part B — Build & Verify (Packet Tracer)

  1. Create 3 routers, switches per department, and 1–2 PCs per subnet.
  2. Configure interface IPs from your plan; set PC gateways.
  3. Configure the WAN links (/30) between routers and a routing method (static or OSPF).
  4. Verify with ping across departments and show ip interface brief.

✅ Verification Checklist

  • Every department has enough usable hosts (and minimal waste).
  • No two subnets overlap.
  • A PC in Sales can ping a PC in Engineering (routing works).
  • WAN links use /30 (2 usable hosts each).

📦 Deliverables

  • Completed design.md addressing table.
  • A Packet Tracer .pkt file (kept locally — the repo ignores .pkt).
  • A short reflection: how much address space did VLSM save vs. giving every subnet a /24?

🚀 Stretch Goals

  • Add a summary route advertised toward an ISP router.
  • Re-do the plan with an IPv6 /48, giving each subnet a /64.

See also notes: [[08-10-vlsm]], [[08-07-subnetting-examples]]