What is difference between layer-3 Switching and Routing?
To understand the difference between L3 Switching and routing, it is better to understand basic definition of switch and router.
Remember the following in case of switch and router:
- Switch is considered as Layer-2 device that performs circuit switch or forwarding decisions based on layer 2 table and Switch performed packet forwarding with hardware switching which is faster than a router.
- According to basic definition of a router, it is a device which performs packet switching or Layer-3 forwarding and this layer-3 routing forwarding were typically performed in software or by means of programing algorithms. If you have clear understanding of packet vs circuit switching then you can understand this concept easily.
In modern world there are most of routers those can perform Layer-3 forwarding using hardware as well. Therefore, both Layer 3 switch and Layer-3 router can perform nearly identical functions with same performance. But there are still some differences in operations of Layer-3 switches and routers as following:
- Layer-3 switches are enhanced for Ethernet, and are mainly used for inter-VLAN routing. These Layer-3 switches can also perform their basic Layer-2 forwarding for intra-VLAN traffic.
- A layer-3 Switches generally have higher number of ports as compare to routers, and are consider as a cheaper device in term of per port cast as compare to routers
- Routers are specially build for routing therefore they support a large number of WAN technologies as compare to Layer-3 switches, L3 switches normally do not have WAN interfaces & do not support the advance routing or WAN technologies.
- Layer 3 switches are frequently installed at the top of LAN in building or in campus networks. Routers are predominantly used for connecting to WAN, therefore they are deployed at core layer or in main data Center.
- Router perform routing lookup, by introducing fast switching and CEF, packets are also now switched on a router.Switches doesn’t support some QoS features.