Layer 4 Switch
Definition - What does Layer 4 Switch mean?
A layer 4 switch enables policy based switching mechanisms that limits different traffic types and prioritizes packets based on their base application importance. A layer 4 switch is among the types of multilayer switches, and is an enhancement to the layer 3 switch that uses hardware based switching techniques.
A layer 4 switch is also known as session switch.
Techopedia explains Layer 4 Switch
A layer 4 switch is primarily responsible for the analysis and control of network traffic at layer 4 or the transport layer of OSI mode. It inspects each packet and makes forwarding and routing decisions based on layer 4-7 data.
Layer 4 switches are referred to as session switches, when they perform tasks in more or less the same manner that a firewall does, by monitoring the status of sessions individually from start to end. Similarly, a layer 4 switch when deployed on a cluster of servers, determines which server the user query should be sent to based on the server loads. It can also identify offline servers and directs traffic accordingly.