CSMA/CD

[carl_townshend]

Is this just how an ethernet network switch works ? whereas a hub is not this ?

carl

[hitesharora]

Hi Carl,

Its the otherway round. Its how the hub works, switch is different.

Rgds

[carl_townshend]

so what does what here then ? I thought a switch does this

[bjw]

CSMA/CD - Carrier Sense Multiple Access/Collision Detect.

10Base2 and 10Base5 - typically 10 MB/Half duplex. This is where there is a common tx/rx medium that all connected devices share. Collisions are normal, hosts listen and wait for open time to broadcast/send packets over the wire. This is what a legacy HUB does.

A Switched network allows each connected host/device to have a dedicated slice of the ethernet pie and collisions should theoretically never occur in FULL DUPLEX operation. However a switch port/interface configured as half duplex will electricaly function like it is a CSMA/CD Hub port and will normally accumulate collision errors, but ONLY on that port/interface, all other switch ports/interfaces running full duplex will never see these errors/conditions.

[carl_townshend]

I have just been told by a ccie that csma/cd works on all ethernet networks no matter if its plugged into a hub or switch ? is this true ? can anyone explain in simple terms what it does ?

cheers

Carl