In the Homelab: Mastering the Network series, we’ll walk through the essential networking skills that power a reliable and secure home lab. From IP planning and VLANs to routing, firewalling, and monitoring, each guide is designed to give you copy-ready steps, clear examples, and practical tools to level up your lab—no guesswork required.

We’re starting with the foundation: IP address planning and subnetting. Whether you’re managing a few Raspberry Pis or building out a multi-VLAN lab with a rack of gear, having a thoughtful IP scheme is critical. Without it, your network can quickly become chaotic, hard to scale, and frustrating to troubleshoot.

In this first guide, you’ll learn how to segment your network using CIDR notation, calculate usable IP ranges, and create a layout that supports both simplicity and growth. If you’re aiming for a homelab that’s clean, scalable, and easy to manage, this is where to begin.

Why Subnetting Matters in a Homelab

Subnetting helps you logically divide your network into manageable sections. For a homelab, this enables:

• Clear separation between systems (e.g., production vs. test, media vs. IoT)
• Easier implementation of firewall rules and VLANs
• Cleaner network documentation
• Fewer IP conflicts and better scalability

Even if your lab is behind a single NAT router today, subnetting sets the stage for more advanced architecture later.

CIDR Notation and Subnet Masks

CIDR (Classless Inter-Domain Routing) notation defines how many bits are used for the network portion of an IP address.

• Example: 192.168.10.0/24 means the first 24 bits are the network, and the rest are for hosts.
• This gives you 256 IPs total (2^8), but only 254 usable (you lose one for the network and one for the broadcast address).

Quick Tips

• Use /24 for simple networks or VLANs — easy to remember, overkill for 5–10 hosts, but good for growth.
• Use /27 or /28 for tightly scoped segments like IoT or guests.
• Avoid overlapping subnets (e.g., don’t use 192.168.1.0/24 and 192.168.1.128/25 on the same interface).

Planning Your IP Scheme

You don’t need to be a service provider to have good documentation. A little planning goes a long way.

Sample Structure

Reserved Ranges for Homelab Use

Use private IPs per RFC 1918:

• 10.0.0.0/8 – Big enough for serious labs
• 172.16.0.0/12 – Ideal for mid-size segmenting
• 192.168.0.0/16 – Most common for home networks

Pro tip: avoid 192.168.1.0/24 unless you want to fight with default router configs.

Subnet Calculators and Tools

Don’t do subnet math in your head unless you enjoy pain. Here are some solid tools:

• https://subnet.ipcalc.org/
• https://www.ipaddressguide.com/cidr
• https://networkcalc.com/ip

For mapping out your network visually:

• Draw.io
• Lucidchart
• Inkscape for more custom diagrams

Final Tips for Clean IP Management

• Document everything. Use a spreadsheet, wiki, or IPAM tool (e.g., phpIPAM).
• Avoid overlaps. Leave buffer space between ranges for future VLANs or VPNs.
• Label your devices. Match hostnames, DNS entries, and IP assignments where possible.
• Plan for DHCP and static ranges. Example: .1–.50 for static, .100–.200 for DHCP.

A clean, well-planned IP scheme not only makes your network easier to manage — it also lays the foundation for VLANs, firewalling, logging, and scaling. Build your homelab like it’s production, and you’ll spend a lot less time fixing things later.

Need help mapping your lab? Or stuck with overlapping subnets? Reach out here and let’s troubleshoot together.