VLANs in plain English: why segmenting your office network pays off

A VLAN (virtual LAN) splits one switch, or a set of switches, into separate logical networks. Devices in one VLAN cannot talk to devices in another unless a router or firewall allows it.

Why bother?

Security: a guest laptop or a compromised camera cannot reach your file server. Performance: broadcast traffic stays inside each VLAN. Control: you can write simple firewall rules between groups.

A simple office layout

VLAN 10  Staff      192.168.10.0/24
VLAN 20  Servers    192.168.20.0/24
VLAN 30  Guests     192.168.30.0/24
VLAN 40  Cameras    192.168.40.0/24

Staff can reach servers. Guests can only reach the internet. Cameras can reach the recorder and nothing else.

What you need

Managed switches that support 802.1Q tagging, and a router or firewall that can route between VLANs. Plan the addresses first, and write them down before you configure anything.