L2 switch create collision or reduces collisons?

yrwins

quick question.
L2 switch create collision or reduces collisons?

DPG

Switches reduce collisions by creating a separate collision domain per interface.

yrwins

thanks...
I'm confused with "create" broadcast domain and "create" collisions domain . create vs decrease..

so why on book the answer is not A switch decreases the number of collision domains.
if it create broadcast domain!!!!!

Hmmmmm so...
create Broadcast domain but not decreases collision domains????? and also multiple collision domain.

pinkiaiii

switches forward broadcasts example>if it doesnt know mac address it floods frame out off all ports excluding port it received.
routers reduce broadcast domains.thus dont flood frames if they dont have where to send it so frame gets discarded.
even thou hubs may have few ports but they are considered one collision domain - thus while there are few more devices but id recommend getting familiar with each how they treat broadcasts,and collision domains.

OfWolfAndMan

Let's compare a switch to a hub. A switch is aware of the MAC addresses on its ports (after ARP resolution of course). Therefore, it does not flood a frame out all ports, just the one that the MAC address shows up on (Assuming it does). A hub has no concept of this table, therefore it always has to forward to all ports no matter what.

With a broadcast domain, ARP is a perfect example. The destination MAC address in the frame is set to FFFF.FFFF.FFFF (broadcast) and is flooded out all ports of the segment it's initiated on, regardless of the table. If the port is not in the local segment (Let's say local segment is VLAN 10 but VLAN 20 has some ports on the switch), then with an ARP, the broadcast does not forward outside of that segment. Each segment on a switch will have its own broadcast domain.

ypark

If multiple hosts reside in the same collision domain, collisions can happen. Switches decrease (or eliminate) collisions by creating multiple collision domains and essentially putting each host on their own collision domain. So, a switch increases the number of collision domains, which decreases collisions. All hosts on a switch is still on the same broadcast domain since the switch forwards all broadcast traffic.