L2 Managed Switch Vs L3

Layer 2 vs layer 3 switch the main difference between layer 2 and layer 3 is the routing function.

L2 managed switch vs l3.

Since vlans exist in their own layer 3 subnet routing will need to occur for traffic to flow in between vlans. Network layer where it route packet by using ip address it is used widely on vlans. A layer 3 switch builds a layer 2 forwarding table to be able to forward within a vlan. Cisco delivers a comprehensive portfolio of switching solutions for enterprise networks data centers and smaller businesses.

This is where a layer 3 switch can be utilized. A layer 3 switch is basically a switch that can perform routing functions in addition to switching. Routing in layer 2 and layer 3 switch switching operates at layer 2 of the osi reference model where data packets are redirected to a destination port based on mac addresses. So l3 switch happen to be faster than router in forwarding packets.

Now the exceptions l3 switches like 6500 can be loaded with cards which support wan connections also. A layer 3 switch includes the functionality of a layer 2 switch and also is able to use layer 3 information ip addresses to make its forwarding decisions. A layer 2 switch works with mac addresses only and does not care about ip address or any items of higher layers. Data link layer and sends a frames to destination port using mac address table which stores the mac address of a device associated with that port.

So layer 2 switches simple do switching. The traffic forwarding decision is based on its mac address table entries. Layer 3 switch work on layer 3 of osi model i e. The image below shows an example of a multi vlan environment on a layer 2 switch.

This is also the biggest difference lies between layer 2 switch and layer 3 switch. So a layer 3 switch is aware of subnets and networks in addition to being aware of vlans. Layer 2 switch work on layer 2 of osi model i e. Layer 3 switch make its forwarding decision in hardware asic application specific integrated circuits and router make its decision in software intelligence from ios.

A layer 2 managed switch forwards traffic between network hosts such as a server and a client pc within the same subnet. A layer 3 switch on the other hand is a specialized hardware device used for routing data packets using ip.