What is the difference between a Layer 2 and Layer 3 switch?

A Layer 2 switch moves traffic between devices on the same network or VLAN. A Layer 3 switch can also route traffic between VLANs, which a router would otherwise do. Larger offices use Layer 3 at the core so traffic between departments stays fast.

Managed vs unmanaged switch: which do I need?

An unmanaged switch is plug and play, with no settings. A managed switch lets you set up VLANs, see which ports are busy, control PoE and lock down ports. For any office with CCTV, Wi-Fi or more than a handful of users, a managed switch is worth it.

What is a PoE switch?

A switch that also sends power down the network cable. It powers IP cameras, Wi-Fi access points, IP phones and some biometric devices without a separate power supply at each one.

How much PoE power do I need?

Add up what each device draws and check the switch total PoE budget. Standard PoE gives up to 15.4 W per port, PoE+ up to 30 W, and the newer PoE++ standard up to 60 or 90 W. Leave headroom for devices you will add later.

Do I need a separate router if I have a Layer 3 switch?

Usually yes. The Layer 3 switch routes inside your office. You still need a router or firewall at the internet connection.

Network Switches Explained: Managed vs Unmanaged, Layer 2 vs Layer 3

Quick answer

An unmanaged switch is plug and play. A managed switch lets you split the network into VLANs and control each port. A Layer 2 switch connects devices on the same network; a Layer 3 switch can also route between networks. Most offices need managed Layer 2 switches, with Layer 3 at the core once they grow.

What a switch does

A switch is the box every network cable in your office plugs into. It passes data between computers, printers, cameras, phones and access points, and up to your router or firewall. The type you choose decides how much control you have over all that traffic.

Managed vs unmanaged

	Unmanaged	Managed
Setup	Plug in and it works	Needs configuring
VLANs	No	Yes
Monitoring	None	See traffic, errors and PoE use per port
Security	Any device can plug in	Ports can be locked down or disabled
Good for	A few extra ports at one desk	Any real office network

The big reason to go managed is VLANs. They let you keep staff computers, guest Wi-Fi, CCTV and phones on separate networks using the same cables. If a guest laptop or a camera has a problem, it cannot reach your accounts PC.

Layer 2 vs Layer 3

A Layer 2 switch moves traffic between devices on the same network. Once you have VLANs, something has to pass traffic between them. In a small office the router or firewall does that.

A Layer 3 switch can do that routing itself. In a larger office with many VLANs and floors, putting a Layer 3 switch at the centre keeps traffic between departments fast and takes load off the firewall. Floor switches can stay Layer 2.

PoE switches

PoE (Power over Ethernet) switches send power down the network cable. That is how IP cameras, Wi-Fi access points and IP phones run without a power socket next to each one.

Every PoE switch has a total power budget. Add up what your devices draw and leave room to grow. Cameras with heaters or motorised lenses, and newer access points, can need much more than basic PoE.

A sensible starting point

Small office, one floor: one managed PoE switch, with VLANs for staff, guests and CCTV.
Several floors or departments: managed Layer 2 switches on each floor, linked to a Layer 3 core switch in the rack.
Heavy CCTV: keep cameras on their own VLAN, and size PoE and uplinks for the total camera bitrate.

Cables matter too. Uplinks between switches are where faster cable pays off. See our Cat6 vs Cat6A guide.

Last updated 4 November 2026