What is a layer 3 switch?
Simply put, a layer 3 switch combines the functionality of a switch and a router. It acts as a switch to connect devices that are on the same subnet or virtual LAN at lightning speeds and has IP routing intelligence built into it to double up as a router. It can support routing protocols, inspect incoming packets, and can even make routing decisions based on the source and destination addresses. This is how a layer 3 switch acts as both a switch and a router.
level 3 router
Often referred to as a multilayer switch, a layer 3 switch adds a ton of flexibility to a network.
Features of a layer 3 switch
Purpose of a layer 3 switch
There is a ton of confusion about the use of a layer 3 switch because in a traditional setup, routers operate at layer 3 of the OSI model while switches operate at layer 2. So, how does this layer 3 switch fit into this model? Also, the name “layer 3 switch” causes confusion because switches typically operate from layer 2.
Originally, layer 3 switches were conceived to improve routing performance on large networks, especially corporate intranets. To understand the purpose, let’s step back a bit in time to see how these switches evolved.
Layer 2 switches work well when there is low to medium traffic in VLANs. But these switches would hang when traffic increased. So, it became necessary to augment layer 2’s functionality.
One option was to use a router instead of a switch, but then routers are slower than switches, so this could lead to slower performance.
To overcome this downside, researchers thought about implementing a router within a switch. Though technically feasible, it was not the ideal option because layer 2 switches operate only on the Ethernet MAC frame while layer 3 handles multiple routing protocols.
Researchers felt this was too complicated, so they came up with the idea of a layer 3 switches that acted as routers with fast forwarding done through the underlying hardware.
This is why the main difference between layer 3 switches and routers lies in the hardware. If you were to take a peek into a layer 3 switch’s hardware, you’ll see a mix of traditional switches and routers, except that the routers’ software logic is replaced with integrated circuit hardware to improve performance.
What Should Be Kept in Mind When Using Core Switch?
The first thing we should keep in mind is that core switch is urgently required in two occasions. One occasion is when the access switches are located in different places and there is a aggregation switch in each place, then we need a core switch to optimize the network. Another occasion is when the number of the access switches connecting to a single aggregation switch exceeds the performance of it, and we need to use multiple aggregation switches in a single location, then the use of core switch can reduce the complexity of the network.
In a public WAN, a core switch interconnects edge switches that are positioned on the edges of related networks. In a local area network (LAN), this switch interconnects work group switches, which are relatively low-capacity switches that are usually positioned in geographic clusters.
Simply put, a layer 3 switch combines the functionality of a switch and a router. It acts as a switch to connect devices that are on the same subnet or virtual LAN at lightning speeds and has IP routing intelligence built into it to double up as a router. It can support routing protocols, inspect incoming packets, and can even make routing decisions based on the source and destination addresses. This is how a layer 3 switch acts as both a switch and a router.
level 3 router
Often referred to as a multilayer switch, a layer 3 switch adds a ton of flexibility to a network.
Features of a layer 3 switch
Purpose of a layer 3 switch
There is a ton of confusion about the use of a layer 3 switch because in a traditional setup, routers operate at layer 3 of the OSI model while switches operate at layer 2. So, how does this layer 3 switch fit into this model? Also, the name “layer 3 switch” causes confusion because switches typically operate from layer 2.
Originally, layer 3 switches were conceived to improve routing performance on large networks, especially corporate intranets. To understand the purpose, let’s step back a bit in time to see how these switches evolved.
Layer 2 switches work well when there is low to medium traffic in VLANs. But these switches would hang when traffic increased. So, it became necessary to augment layer 2’s functionality.
One option was to use a router instead of a switch, but then routers are slower than switches, so this could lead to slower performance.
To overcome this downside, researchers thought about implementing a router within a switch. Though technically feasible, it was not the ideal option because layer 2 switches operate only on the Ethernet MAC frame while layer 3 handles multiple routing protocols.
Researchers felt this was too complicated, so they came up with the idea of a layer 3 switches that acted as routers with fast forwarding done through the underlying hardware.
This is why the main difference between layer 3 switches and routers lies in the hardware. If you were to take a peek into a layer 3 switch’s hardware, you’ll see a mix of traditional switches and routers, except that the routers’ software logic is replaced with integrated circuit hardware to improve performance.
What Should Be Kept in Mind When Using Core Switch?
The first thing we should keep in mind is that core switch is urgently required in two occasions. One occasion is when the access switches are located in different places and there is a aggregation switch in each place, then we need a core switch to optimize the network. Another occasion is when the number of the access switches connecting to a single aggregation switch exceeds the performance of it, and we need to use multiple aggregation switches in a single location, then the use of core switch can reduce the complexity of the network.
In a public WAN, a core switch interconnects edge switches that are positioned on the edges of related networks. In a local area network (LAN), this switch interconnects work group switches, which are relatively low-capacity switches that are usually positioned in geographic clusters.
No comments:
Post a Comment