نوشته اصلی توسط youness
Yes , you are correct about the architectural difference ? but where is difference ?
making statement in technology is not killing one bird with two stones !
So the problem you made on your statement is :
I routers we do packet forwarding and in L3 switches do packet switching, the difference between them refers .back to architecture of these two devices
first let me explain something, we have
L2 forwarding L3 forwarding
Hardware switching and software switching
routers and switched both use the same concept.
in routers we have CEF table which does the forwarding in hardware for packets. same concept as Switches.hardware switching happens at the port level and it doesnt relates to L2 or L3 packets .it just means using the ASIC's and the pre populated tables such as CEF, CAM, TCAM and .../ so even in routers we have hardware switching but if we have any special operation which requires modification on the packet something like header re-write , packet generation (router generated traffic or even NAT ) , policy on forwarding (policy based-routing) or any similar operation, then actions should be done by the software processor and then passed on. and this the tie breaker of the performance issues between the router and switch.
ok do one test
have router with two gigabit ethernet ports
connect two PC's to these ports.
set two seperate IP subnets on the ports connect to each pc
PC 1 ---> port 1(ROUTER)port 2---> PC 2
router port 1: 192.168.1.1
PC 2 --> 192.168.2.2
Router port 2 : 192.168.2.1
try out the following test
first enable CEF, use Solarwinds WAN Killer and send traffic from Port 1 to Port 2
watch the rate and the CPU utilization on the Router
On test 2 have the CEF enable and enable NAT between the two subnets
on test 3 ... Disable CEF and enable only PROCESS Switching now try the same operation
you will see the tie breaker !!