undermybelt Homelab VLAN Segmentation
How to split a home network into isolated VLANs so IoT devices, guests, and your main PCs cannot talk to each other. The most impactful security upgrade for a home network.
All firewall rules shown here add isolation between segments — they do not remove existing protections. Apply changes in a maintenance window and verify connectivity between segments after each step before moving on.
When to Use
- Setting up VLANs on a home network for the first time
- Isolating IoT devices (smart bulbs, cameras, TVs) from trusted devices
- Creating a guest Wi-Fi network that cannot reach home devices
- Explaining how VLANs work to someone unfamiliar with the concept
- Configuring trunk ports, access ports, and SSID-to-VLAN mapping
- Troubleshooting inter-VLAN routing or firewall rule issues on pfSense/OPNsense/UniFi
How It Works
Without VLANs — flat network:
All devices on 192.168.1.0/24
Smart TV (potential malware) → can reach your NAS, PCs, everything
With VLANs:
VLAN 10 — Trusted 192.168.10.0/24 (PCs, phones, laptops)
VLAN 20 — IoT 192.168.20.0/24 (smart TV, bulbs, cameras)
VLAN 30 — Servers 192.168.30.0/24 (NAS, Pi, VMs)
VLAN 40 — Guest 192.168.40.0/24 (visitor Wi-Fi)
VLAN 99 — Management 192.168.99.0/24 (switch/AP web UIs)
Smart TV → blocked from reaching 192.168.10.0/24 and 192.168.30.0/24
Guests → internet only, cannot see any home devices
VLAN Design Template
VLAN Name Subnet Gateway Purpose
10 trusted 192.168.10.0/24 192.168.10.1 PCs, phones, laptops
20 iot 192.168.20.0/24 192.168.20.1 Smart home devices
30 servers 192.168.30.0/24 192.168.30.1 NAS, Pi, self-hosted
40 guest 192.168.40.0/24 192.168.40.1 Visitor Wi-Fi
99 management 192.168.99.0/24 192.168.99.1 Network gear web UIs
Examples
Typical homelab with UniFi AP and managed switch:
Scenario: 3-bedroom house, UniFi Dream Machine + UniFi 8-port switch + 2 APs
VLAN 10 — Trusted 192.168.10.0/24 MacBook, iPhones, iPad
VLAN 20 — IoT 192.168.20.0/24 Nest thermostat, Philips Hue, Ring doorbell, smart TVs
VLAN 30 — Servers 192.168.30.0/24 Synology NAS (192.168.30.10), Pi-hole (192.168.30.2)
VLAN 40 — Guest 192.168.40.0/24 Visitor Wi-Fi — internet only
SSID → VLAN mapping:
"Home" → VLAN 10 (WPA2, strong password, trusted devices only)
"IoT" → VLAN 20 (WPA2, separate password, printed on router for setup)
"Guest" → VLAN 40 (WPA2, simple password you can share freely)
Switch port behavior:
Port 1 → trunk to router (tagged VLANs 10,20,30,40,99)
Port 2 → trunk to APs (tagged VLANs 10,20,40; AP handles per-SSID tagging)
Port 3 → access VLAN 30 (NAS — untagged, no VLAN awareness needed)
Port 4 → access VLAN 30 (Pi-hole — untagged)
Port 5–8 → access VLAN 10 (wired workstations)
Firewall rules applied (all rules add isolation, none remove existing protections):
IoT → Trusted: BLOCK
IoT → Servers: BLOCK except 192.168.30.2:53 (Pi-hole DNS allowed)
IoT → Internet: ALLOW
Guest → Local networks: BLOCK
Guest → Internet: ALLOW
Trusted → everywhere: ALLOW
UniFi Configuration
Create Networks in UniFi Controller
Settings → Networks → Create New Network
For each VLAN:
Name: IoT
Purpose: Corporate (gives DHCP + routing)
VLAN ID: 20
Network: 192.168.20.0/24
Gateway IP: 192.168.20.1
DHCP: Enable
DHCP Range: 192.168.20.100 – 192.168.20.254
Map SSIDs to VLANs (UniFi)
Settings → WiFi → Create New WiFi
Name: IoT-Network
Password: <separate password>
Network: IoT ← select your VLAN here
# All devices connecting to this SSID land in VLAN 20
Name: Guest
Password: <guest password>
Network: Guest
Guest Policy: Enable ← isolates guests from each other too
UniFi Firewall Rules (Traffic Rules)
Settings → Traffic & Security → Traffic Rules
# Block IoT from reaching Trusted VLAN
Action: Block
Category: Local Network
Source: IoT (192.168.20.0/24)
Destination: Trusted (192.168.10.0/24)
# Allow IoT to reach internet only
Action: Allow
Source: IoT
Destination: Internet
# Block Guest from all local networks
Action: Block
Source: Guest
Destination: Local Networks
pfSense / OPNsense Configuration
Create VLANs
Interfaces → Assignments → VLANs → Add
Parent Interface: em1 (your LAN NIC)
VLAN Tag: 20
Description: IoT
# Repeat for each VLAN, then assign each VLAN to an interface:
Interfaces → Assignments → Add
Select the VLAN you created → click Add
Enable the interface, set IP to gateway address (192.168.20.1/24)
DHCP for Each VLAN
Services → DHCP Server → Select your VLAN interface
Enable DHCP
Range: 192.168.20.100 to 192.168.20.254
DNS Servers: 192.168.30.2 ← Pi-hole IP if you have one
Firewall Rules (pfSense/OPNsense)
# Rules are processed top-to-bottom, first match wins.
# On the IoT interface (VLAN 20):
Rule 1: Allow IoT → Pi-hole DNS ← MUST come before the RFC1918 block rule
Protocol: UDP/TCP
Source: IoT net
Destination: 192.168.30.2 port 53
Action: Allow
Rule 2: Block IoT → RFC1918 (all private IP ranges)
Protocol: any
Source: IoT net
Destination: RFC1918 (192.168.0.0/16, 10.0.0.0/8, 172.16.0.0/12)
Action: Block
Rule 3: Allow IoT → internet
Protocol: any
Source: IoT net
Destination: any
Action: Allow
# On the Trusted interface (VLAN 10):
Allow all (trusted devices can reach everything)
Source: Trusted net
Destination: any
Action: Allow
# Additional exceptions for IoT devices that need specific local services:
Insert before Rule 2 (the RFC1918 block):
Protocol: TCP
Source: IoT net
Destination: 192.168.30.x port 8123 ← Home Assistant
Action: Allow
MikroTik Configuration
# Step 1: Create a bridge with VLAN filtering enabled
/interface bridge
add name=bridge vlan-filtering=yes
# Step 2: Add physical ports to the bridge
# Trunk port to router/uplink (tagged for all VLANs)
/interface bridge port
add bridge=bridge interface=ether1 frame-types=admit-only-vlan-tagged
# Access port for trusted devices (untagged VLAN 10)
/interface bridge port
add bridge=bridge interface=ether2 pvid=10 frame-types=admit-only-untagged-and-priority-tagged
# Access port for IoT devices (untagged VLAN 20)
/interface bridge port
add bridge=bridge interface=ether3 pvid=20 frame-types=admit-only-untagged-and-priority-tagged
# Step 3: Define which VLANs are allowed on which ports
/interface bridge vlan
add bridge=bridge tagged=ether1 untagged=ether2 vlan-ids=10
add bridge=bridge tagged=ether1 untagged=ether3 vlan-ids=20
# Step 4: Create VLAN interfaces on the bridge (gateway IPs)
/interface vlan
add interface=bridge name=vlan10 vlan-id=10
add interface=bridge name=vlan20 vlan-id=20
# Step 5: Assign gateway IPs
/ip address
add interface=vlan10 address=192.168.10.1/24
add interface=vlan20 address=192.168.20.1/24
# Step 6: DHCP pools and servers
/ip pool
add name=pool-trusted ranges=192.168.10.100-192.168.10.254
add name=pool-iot ranges=192.168.20.100-192.168.20.254
/ip dhcp-server
add interface=vlan10 address-pool=pool-trusted name=dhcp-trusted
add interface=vlan20 address-pool=pool-iot name=dhcp-iot
/ip dhcp-server network
add address=192.168.10.0/24 gateway=192.168.10.1
add address=192.168.20.0/24 gateway=192.168.20.1
# Step 7: Firewall — block IoT from reaching trusted VLAN
/ip firewall filter
add chain=forward src-address=192.168.20.0/24 dst-address=192.168.10.0/24 \
action=drop comment="Block IoT to Trusted"
Switch Trunk vs Access Ports
# Trunk port: carries multiple VLANs (tagged) — connects switch-to-switch, switch-to-router, switch-to-AP
# Access port: carries one VLAN (untagged) — connects to end devices (PC, camera, NAS)
# A managed switch port connected to your router should be a trunk:
Allowed VLANs: 10, 20, 30, 40, 99
# A port connecting to a PC should be an access port:
VLAN: 10 (trusted)
No tagging — the PC does not know or care about VLANs
# A port connecting to an AP must be a trunk:
The AP tags traffic from each SSID with the right VLAN ID
Allowed VLANs: 10, 20, 40 (whichever SSIDs the AP serves)
Anti-Patterns
# BAD: Creating VLANs without adding firewall rules
# VLANs without firewall rules do not provide security — inter-VLAN routing is open by default
# GOOD: Add explicit block rules immediately after creating VLANs
# BAD: Putting the Pi-hole in the IoT VLAN
# IoT devices can reach it but trusted devices cannot (without extra rules)
# GOOD: Pi-hole in the Servers VLAN with a rule allowing all VLANs to reach port 53
# BAD: Native VLAN equals management VLAN
# Untagged traffic landing in your management VLAN enables VLAN hopping attacks
# GOOD: Use a dedicated unused VLAN as native (e.g. VLAN 999), keep management traffic tagged
# BAD: Same Wi-Fi password for IoT SSID and trusted SSID
# Anyone who learns the password can connect IoT devices to the wrong segment
Best Practices
- Start with 4 VLANs: Trusted, IoT, Servers, Guest — add more as needed
- Put Pi-hole in the Servers VLAN (192.168.30.x)
- Add a firewall rule allowing DNS (port 53) from all VLANs to the Pi-hole IP — before any RFC1918 block rule
- Test isolation after every rule change: from the IoT VLAN, try to ping a trusted device — it should fail
- Use a management VLAN for switch and AP web UIs and restrict access to the Trusted VLAN only
- Document your VLAN design in a table (VLAN ID, name, subnet, purpose)
Related Skills
- homelab-network-setup
- homelab-pihole-dns
- homelab-wireguard-vpn