What is the difference between layer 2 and layer 3 in the
OSI model?
- 14 Answers
- 62392 Views
- DELL, Open University of Tanzania, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / swathi
The layer2 ,datalink layer is responsible for moving frames
from one hop(node)to the next.Whereas in layer3 i,e network
layer is responsible for the delivery of individual packets
from source host to destination host.
| Is This Answer Correct ? | 242 Yes | 16 No |
Answer / ahmed
Basically a layer 2 switch operates utilizing Mac addresses
in it's caching table to quickly pass information from port
to port. A layer 3 switch utilizes IP addresses to do the
same.
While the previous explanation is the "What", for folks in
networking the following "How" is far more interesting.
Essentially, A layer 2 switch is essentially a multiport
bridge. A layer 2 switch will learn about MAC addresses
connected to each port and passes frames marked for those
ports. It also knows that if a frame is sent out a port but
is looking for the MAC address of the port it is connected
to and drop that frame. Whereas a single CPU Bridge runs in
serial, todays hardware based switches run in parallel,
translating to extremly fast switching.
Layer 3 switching is a hybrid, as one can imagine, of a
router and a switch. There are different types of layer 3
switching, route caching andtopology-based. In route
caching the switch required both a Route Processor (RP) and
a Switch Engine (SE). The RP must listen to the first
packet to determine the destination. At that point the
Switch Engine makes a shortcut entry in the caching table
for the rest of the packets to follow. Due to advancement
in processing power and drastic reductions in the cost of
memory, today's higher end layer 3 switches implement a
topology-based switching which builds a lookup table and
and poputlates it with the entire network's topology. The
database is held in hardware and is referenced there to
maintain high throughput. It utilizes the longest address
match as the layer 3 destination.
Now when and why would one use a l2 vs l3 vs a router?
Simply put, a router will generally sit at the gateway
between a private and a public network. A router can
perform NAT whereas an l3 switch cannot (imagine a switch
that had the topology entries for the ENTIRE Internet!!).
In a small very flat network (meaning only one private
network range for the whole site) a L2 switch to connect
all the servers and clients to the internet is probably
going to suffice. Larger networks, or those with the need
to contain broadcast traffic or those utilizing VOIP, a
multi network approach utilizing VLANs is appropriate, and
when one is utilizing VLANs, L3 switches are a natural fit.
While a router on a stick scenario can work, it can quickly
overtax a router if there is any significant intervlan
traffic since the router must make complicated routing
decisions for every packet that it recieves.
| Is This Answer Correct ? | 70 Yes | 11 No |
Answer / muhammad ali
The layer2 ,datalink layer is responsible for moving frames
from one hop(node)to the next.Whereas in layer3 i,e network
layer is responsible for the delivery of individual packets
from source host to destination host.
| Is This Answer Correct ? | 56 Yes | 5 No |
Answer / brajesh soni
Layer 2 is resposible for sending data b/w 2 node (within
MAC resolution) and Flow, sequence control and error
recovery by retransmission).
while layer 3 is transport the container of data with inter
network.it needs service of 3,4,5 layer to established
session,authentication,packeging data,identification of
data )
| Is This Answer Correct ? | 24 Yes | 12 No |
Answer / naresh
The layer2 ,datalink layer is responsible for moving frames
from one hop(node)to the next.Whereas in layer3 i,e network
layer is responsible for the delivery of individual packets
from source host to destination host.
| Is This Answer Correct ? | 14 Yes | 2 No |
Answer / santhi
layer2,datalink layer works based on mac address where as
layer3 i.e., network layer works based on ip address.layer2
sends data(frames) to the network layer. layer2 performs
error detection but not error recovery.
layer2 devices are switches,bridges.L3 devices are
routers,etc.,. switch maintains mac table internally, router
maintains routing table internally.
In L2, the devices within the same network will
communicate,but In L3 , we can communicate with other
networks also.ie., different networks communicate by using
router or L3 switches etc.,.
| Is This Answer Correct ? | 13 Yes | 3 No |
Answer / manpreet singh
Layer 2 Switches (The Data-Link Layer)
Layer 3 Switches (The Network Layer)
Layer 4 Switches (The Transport Layer)
| Is This Answer Correct ? | 38 Yes | 31 No |
Answer / sathish
The layer2 is a Data link layer which is responsible for
communication between adjacent network node, switch is
operate the data link layer.
Whereas, layer3 is a Network layer which is responsible for
establishing the path for data transfer through the
network, and delivering the packets, router operates the
Network layer.
| Is This Answer Correct ? | 7 Yes | 1 No |
Answer / malik muhammad mehran
On layer 2 switching is performed datagrams forward on the
basis of MAC address( switches work on this layer), in
layer 3 routing is performed data moved on the basis of IP
address( routers work on this layer)...
| Is This Answer Correct ? | 14 Yes | 10 No |
What is what is the height of esma card?
What do you mean by fdma? Explain?
What is the total output power of an complete bts, in dbm and watts?
What are the different types of GSM antenna?
How to know that 10 seconds free for every minute in local calls made by customres by his Itemised bill
Tell me what is the maximum number of satellite hops allowed in voice communication?
How cdma is different from gsm?
What do you mean by fdma?
What is MTU?
how to do dg commissoning?
What is frequency band for 3g?
How cdma works?
Telecom Routers Switches 
