layer 2 is for peer to peer communication

layer 3 is for process to process commmunication

Hi

There is only one big diffrence between layer 2 and layer 3 swithces is that we are able to do routing in interanetwork with Layer 3 swithces which is not possible to do with layer 2. Cisco 2950 catalyst swithe is the example of that.

K.Shridhar

Hcl Comnet

Layer 2 switch can only do switching where as Layer 3 can do switching as well as routing

Ex: of layer 2 switches 1912 2950

layer 3 switches 4503 5500

Hi...............

I didn't understand what do u mean by peer to peer and process to process.

As per me is concerned layer 2 switch can only do switching where as layer 3 switch can do switching as well as routing.............

Ex: layer 2 switch: 2950 1900

layer 3 switch: 4503 5500

layer 2 is do the routing function with the mac address(ie peer to peer delivery) but laywr 3 is do the routin function with the ip address(process to process delivery)

by

Raja.m

hi

on layer 2 in the header portion(H2) contains source and destination physical addresses...(means all the computers which are in the same network can communicate.......)

while on layer 3 in the header portion(H3) contains logical ip of the source and in the destination portion it contains logical ip of gateway of that(of source) network. and then in the second pass in H3 it contains in the source portion address of the gateway and in the destination portion address of the real destination.( packet can be trasferred though source and the destination are of the different networks)

source 192.168.0.12 subnet255.255.255.0 (here n/w id 192.168.0.0.0)

destination 100.100.100.13 subnet 255.255.255.0 (here n/w id 100.100.0.0)

so with layer 3 switch

pass1----source(192.168.0.12) to gateway(192.168.0.1)

pass2----gateway(100.100.100.1) to destination(100.100.100.13)

where gateway contains both ip addresses of both the networks.

switch comes in layer two ie data link layer

and router comes in layer 3 ie network layer

usually nodes communicate with each using switch now say there is a V-LAN configured in the switch say there are four (ABCD) nodes connected to the switch. now say A B are in one V-LAN and C D in one V-LAN now if A want to communicate with D using switch it is not possible here we need router. Now if A sends a packet to D the packet goes to switch and then to router and comes back to the switch and goes to D

Here the layer 3 switch comes into picture

layer 3 switch acts like a router i.e router in a switch now if A sends packet to D it is routed internally

here we dont need a router to connect to the internet too