Difference between L2 and L3 Switch

What is Difference between a L2 and L3 Switch.

We all have heard about Layer-2 and Layer-3 switches. The difference between layer 2 and layer 3 switches is always an important thing to keep in mind.

On a Layman point, the L2 and L3 switch differs from each other primarily in the routing function.  

A L2 switch works with MAC addresses only and does not works on IP address or any others. Whereas, L3 switch has capable of doing all the job of a layer 2 switch and additional static routing and dynamic routing as well.

Therefore, a Layer 3 switch has both MAC address table and IP routing table, and it handles intra-VLAN communication and packets routing between different VLANs. L3 is mostly used for VLAN configurations and it has multiple broadcast domain. In L3 it enhances more security, reliability, power.

Difference between a L3 switch and Router

Similarly in transport layer, the router has the L3 feature but the router is always advised for network where there is requirement of WAN, Internet or ISP integration there.

A router have below features which are not available in L3 switches.

• WAN
• WAN Interface
• NAT
• Advanced Routing
• QoS
• Tunneling
• IPSec
• Support multiple routing table

When buying a Layer 2 or Layer 3 switch, there are some key parameters that need to be checked such as forwarding rate, backplane bandwidth, number of VLANs, memory of MAC address, latency, etc.

So this was just a basic note for understanding. If you have any comments please feel free to post. 

Thank you.

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-DR