Use a layer 3 switch for inter-VLAN routing when a network has multiple VLANs and needs traffic to move between them locally, without sending all internal traffic through a separate router. This approach suits complex deployments with high-bandwidth applications, such as AV over IP, surveillance, Wi-Fi, and multi-gigabit network services, while also supporting more efficient traffic flow and network segmentation.

Choose port speeds based on connected devices and traffic, such as Gigabit for standard endpoints, 2.5G for higher-bandwidth access points or internet services, and 10G for demanding AV-over-IP, server, or switch-to-switch connections. Select a port count that covers current devices plus planned expansion, and consider SFP or SFP+ uplinks for fiber connections, longer inter-switch runs, or higher-capacity backbone links.

Power over Ethernet (PoE) capabilities affect layer 3 switch selection by determining whether the switch can power connected devices such as access points, cameras, phones, and other network endpoints. Review the required PoE standard, per-port output, total power budget, and available port count to match the installation, while using Layer 3 features for routing and network segmentation.

Layer 3 switches support AV over IP by using VLANs, inter-VLAN routing, and multicast routing protocols such as IGMP and PIM to direct media traffic efficiently across the network. Models with multi-gigabit Ethernet, 10G SFP+ uplinks, and expansion options can connect additional switches, endpoints, and distribution points as the system grows.