Generally, Layer 3 switches are faster than routers, but they usually lack some of the advanced functionalities of routers.
Specifically, a router is a device that routes the packets to their destination. What this means is that a router analyzes the Layer 3 destination address of every packet, and devises the best next hop for it. This process takes time, and hence every packet encounters some delay because of this.
In a Layer 3 switch, on the other hand, whenever a routing table searches for any specific destination, a cache entry is made in a fast memory. This cache entry contains the source-destination pair and next hop address. Once this cache entry is in place, the next packet with the same source and destination pair does not have to go through the entire process of searching the routing table. Next hop information is directly picked up from the cache. That's why it is called route once switch many. This way, a Layer 3 switch can route packets much faster than the router.
Having explained the mechanism of both a router and a Layer 3 switch, let me also tell you that router has some advanced routing functionality, which Layer 3 switches lack. Layer 3 switches are primarily used in the LAN environment, where you need routing. Routers are used in the WAN environment. These days lots of people have started using layer 3 switches in WAN environment, like MPLS.
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RE: what is the diffrence between layer 3 switch and r...
Hello friend Actually there is nothing difference between layer 3 switch and a router. remember that routers are also switches and so even also called as layer 3 switch. As we have layer 2 switches that forwards or filters frames routers( or layer 3 switches) use logical addressing and provide what is called packet switching. Note the term packet switching which i said just now...if u have any doubts feel free to ask me..........my another email id is manja_friends@yahoo.co.inim still a fresher also ccna certified..i havent got any job bcoz of no experience.......... u also complete ur certification........ im still searching for jobs.take care........bye
RE: what is the diffrence between layer 3 switch and r...
thanks ..i did CCNA too and hunting out for job nyways
layer 3 switch is a multiport bridge with a router added in. Layer 3 switches are faster than routers but they usually lack some of the advanced functionalities of routers.
A router is a device that routes the packets to their destination. It means that a router analyzes the Layer 3 destination address of every packet and devises the best next hop for it. This process takes time and hence every packet encounters some delay because of this.
In a Layer 3 switch on the other hand whenever a routing table searches for any specific destination a cache entry is made in a fast memory. This cache entry contains the source-destination pair and next hop address. Once this cache entry is in place the next packet with the same source and destination pair does not have to go through the entire process of searching the routing table.
That's why it is called route once switch many. This way a Layer 3 switch can route packets much faster than the router.
Having explained the mechanism of both a router and a Layer 3 switch router has some advanced routing functionality which Layer 3 switches lack. Layer 3 switches are primarily used in the LAN environment where you need routing . Routers are used in the WAN environment. These days lots of people have started using layer 3 switches in WAN environment like MPLS.
RE: what is the diffrence between layer 3 switch and r...
Layer 3 switch layer 2 switch + router and all MAC-packets switched between to interfaces are not anylized on layer 3. There are a lot of applications when you use Layer 2 switch only on first step of project (for example 48 x 3 144 ports) . Later should be installed one layer 3 switch and all 192 (144 + new 48) will be routed on layer 3. That's why it's faster.
RE: what is the diffrence between layer 3 switch and r...
Generally Layer 3 switches are faster than routers but they usually lack some of the advanced functionalities of routers.
Specifically a router is a device that routes the packets to their destination. What this means is that a router analyzes the Layer 3 destination address of every packet and devises the best next hop for it. This process takes time and hence every packet encounters some delay because of this.
In a Layer 3 switch on the other hand whenever a routing table searches for any specific destination a cache entry is made in a fast memory. This cache entry contains the source-destination pair and next hop address. Once this cache entry is in place the next packet with the same source and destination pair does not have to go through the entire process of searching the routing table. Next hop information is directly picked up from the cache. That's why it is called route once switch many. This way a Layer 3 switch can route packets much faster than the router.
Having explained the mechanism of both a router and a Layer 3 switch let me also tell you that router has some advanced routing functionality which Layer 3 switches lack. Layer 3 switches are primarily used in the LAN environment where you need routing. Routers are used in the WAN environment. These days lots of people have started using layer 3 switches in WAN environment like MPLS.
RE: What is the difference between layer 3 switch and ...
The difference between layer 3 switch and layer 2 switch is that in layer 3 switch WAN acess is possible where as in layer 2 switch WAN acess is not possible
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