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Subnetting Plan

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aljimenez28 edited this page Oct 5, 2025 · 1 revision

Subnetting Plan

This document gives a clear and easy subnetting plan for the entire campus network.
We start with the main block: 10.50.0.0/16
Then we divide it into smaller subnets using VLSM (Variable Length Subnet Masking) — meaning each area only gets as many IPs as it needs.

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🧾 Subnet Table

Location Needed Hosts CIDR Subnet Mask Network Address Usable Range Broadcast Gateway (Router IP)
WiFi Network 1400 /21 255.255.248.0 10.50.0.0 10.50.0.1 – 10.50.7.254 10.50.7.255 10.50.0.1
Central Office 1100 /21 255.255.248.0 10.50.8.0 10.50.8.1 – 10.50.15.254 10.50.15.255 10.50.8.1
East Wing 615 /22 255.255.252.0 10.50.16.0 10.50.16.1 – 10.50.19.254 10.50.19.255 10.50.16.1
West Wing 550 /22 255.255.252.0 10.50.20.0 10.50.20.1 – 10.50.23.254 10.50.23.255 10.50.20.1
Telecommuter VPN Pool 100 /25 255.255.255.128 10.50.24.0 10.50.24.1 – 10.50.24.126 10.50.24.127 10.50.24.1

🧠 Easy Explanations

🛰️ WiFi Network

  • Why /21? It supports 2046 usable IPs — more than enough for 1400 WiFi devices.
  • Purpose: Covers all laptops, phones, and tablets.
  • Gateway: 10.50.0.1 (router or switch for WiFi users).

🏢 Central Office

  • Why /21? Same size as WiFi — 2046 usable IPs, fits 1100 users easily.
  • Purpose: All employee systems and servers in the main building.
  • Gateway: 10.50.8.1 (core router or switch).

🧭 East Wing

  • Why /22? Supports 1022 usable IPs — fits 615 with room to grow.
  • Purpose: East building workstations, printers, and IoT devices.
  • Gateway: 10.50.16.1.

🧱 West Wing

  • Why /22? Same as East Wing, supports 1022 IPs.
  • Purpose: Offices, classrooms, or labs in the West building.
  • Gateway: 10.50.20.1.

💻 Telecommuter VPN Pool

  • Why /25? Supports 126 IPs, perfect for 100 remote users.
  • Purpose: For people connecting remotely through VPN.
  • Gateway: 10.50.24.1.

⚙️ How the Network Connects

  1. Main Router or Layer 3 Switch handles all subnets.
  2. Each subnet connects to a gateway (the first IP in the range).
  3. The router knows how to send data between all subnets.
  4. If you have multiple routers, use static routes or OSPF so they share routes.
  5. DHCP servers can hand out IPs automatically from each range.
  6. Devices can ping each other across subnets once routing is set up.

🔍 How to Test

  1. Connect a device in each subnet and check it gets an IP in the right range.
  2. Ping its gateway (for example, ping 10.50.8.1 from a Central Office device).
  3. Ping another subnet (like WiFi to East Wing).
  4. If both pings work, routing is correct.

🧩 Subnet Size Reference

CIDR Usable Hosts Good For
/25 126 Small (VPN or remote workers)
/22 1022 Medium (Wings or buildings)
/21 2046 Large (WiFi or main office)
/16 65,534 Entire organization (starting pool)

✅ Summary

  • Start with 10.50.0.0/16 (your big network).
  • Divide it using VLSM — only give each subnet the size it needs.
  • Use gateways as routers for each subnet.
  • Test with pings between gateways to confirm routing.
  • You now have an organized, easy-to-manage IP plan for the whole campus!
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