Subnetting Plan - aljimenez28/champlain GitHub Wiki
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) โ meaning each area only gets as many IPs as it needs.
๐งพ 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 โ 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 โ 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 โ 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 โ 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 โ 10.50.24.126 |
10.50.24.127 |
10.50.24.1 |
๐ง Easy Explanations
๐ฐ๏ธ WiFi Network
- Why /21? It supports 2046 usable IPs โ 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).
๐ข Central Office
- Why /21? Same size as WiFi โ 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).
๐งญ East Wing
- Why /22? Supports 1022 usable IPs โ fits 615 with room to grow.
- Purpose: East building workstations, printers, and IoT devices.
- Gateway: 10.50.16.1.
๐งฑ 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.
๐ป 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.
โ๏ธ How the Network Connects
- Main Router or Layer 3 Switch handles all subnets.
- Each subnet connects to a gateway (the first IP in the range).
- The router knows how to send data between all subnets.
- If you have multiple routers, use static routes or OSPF so they share routes.
- DHCP servers can hand out IPs automatically from each range.
- Devices can ping each other across subnets once routing is set up.
๐ How to Test
- Connect a device in each subnet and check it gets an IP in the right range.
- Ping its gateway (for example, ping 10.50.8.1 from a Central Office device).
- Ping another subnet (like WiFi to East Wing).
- If both pings work, routing is correct.
๐งฉ 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) |
โ
Summary
- Start with 10.50.0.0/16 (your big network).
- Divide it using VLSM โ 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!