hi i have some difficulty plz reply as s0on as possible.

1 what is csma/cd(i know u are familer with that protocol)
2 what is the need for it

and and 3 rd one in which i need help

how to enable csma/cd at router or switches

shain make it answer as sson as possibele and call me afetr
reply

thanks
jitendera kuamr sinha

Answer Posted / shahin

CSMA/CD (Carrier Sense Multiple Access/Collision
Detection)is media-access mechanism is what keeps networks
running.

If two or more computers transmit data at the same time, we
get data collision. And thus, no data is sent or received.

We have CSMA/CD for both preventing and controlling collisions.

Suppose 4 system connected as on bus topology or connected
on a Hub.

As we know, in Hub one collision domain & one broadcast
domain. More simply, Hub port just copied data wat it
received & paste it on the rest of the port apart from dat
port from where hub received this data.

So how its detects collision...

Before sending any data, Ethernet NIC first test the voltage
of the line. If its normal, i mean voltage level on line its
start sending data. (Specific voltage level value i didn't
remember).

If two NIC test this voltage level at the same time & they
found its normal for start sending data. When they send
data, data will collide somewhere in the line. Hence data
lose occur & delay in communication.

When NIC detects collision, they wait for random period of
time. (Time i didn't remember). After certain time period
they test the line again & if they found normal. they will
start sending data.

Note: CSMA/CD is not used on Full Duplex Ethernet networks.


3rd Question:

As far my knowledge, there is no such specific command for
this. But we can make any full duplex line in to half duplex
also.

Router(config)#interface fastethernet 0/0
Router(config-if)#duplex ?
auto Enable AUTO duplex configuration
full Force full duplex operation
half Force half-duplex operation



Buddy, i can say this much about it. Hope it may help u
little bit..!!!

Thankx for nice question.

Is This Answer Correct ?    5 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What are the differnt memory use in cisco router?

629


Name the command we give for see routing table?

1946


How many reserve ports?

703


What does eq means?

670


Which peer authentication method and which ipsec mode is used to connect to the branch locations?

595






Differentiate User Mode from Privileged Mode?

790


What will be the prefix length of 224 in vlsm?

655


What does protocol mean?

719


Give some benefits of LAN switching.

915


What are the things that can be accessed in a CISCO router’s identifying information?

697


What are the advantages of lan switching?

611


What is the logical link control?

691


What is a vlan?

675


Can you describe the Authentication Header (AH) Protocol?

2093


How many maximum paths you can give on latest ios in rip?

662