question about the collision domain

[oldtown]

if you have a switch with four interfaces that means you have four collision domains. The question is why you have collision domain whne you connect the switch to the PC. you connectting using a full duplex?

[abdul_uk]

so the PC can send and receive on the same time

AM NOT SURE ABOUT THIS ANSWER AND AM SURRY IF ITS WRONG

[frozenEyes]

if you have a switch with four interfaces that means you have four collision domains. The question is why you have collision domain whne you connect the switch to the PC. you connectting using a full duplex?


well , i will quote some basic words to deliver you the simple explaination
"A collision domain is an area in which a collision can occur. Fair enough, but what "collision" are we talking about here? We're talking about collisions that occur on CSMA/CD segments, or Carrier Sense Multiple Access with Collision Detection. If two hosts on an Ethernet segment transmit data at exactly the same time, the data from the two hosts will collide on the shared segment. CSMA/CD exists to lessen the chances of this happening, but collisions can still occur. To lessen the chances of collisions occurring, we may decide to create multiple, smaller collision domains."

Ethernet devices can use FDX only when collisions cannot occur on the attached cable; a
collision-free link can be guaranteed only when a shared hub is not in use.

so why it can't be collisions between PC and SW ? because they send and receive data on different pairs of cables, you know that PC network interface card (NIC) transmits on pair 1,2 and receives on
pair 3,6; switch ports do the opposite .So, a straight-through cable works well, connecting pair 1,2
on the PC (PC transmit pair) to the switch port’s pair 1,2, on which the switch receives. When the
two devices on the ends of the cable both transmit using the same pins, a cross-over cable is
required. For instance, if two connected switches send using the pair at pins 3,6 and receive on
pins 1,2, then the cable needs to connect the pair at 3,6 on one end to pins 1,2 at the other end, and
vice versa.

HTH,
:)