- A. duplex mismatches on Ethernet segments in the same VLAN
- B. multiple errors on switchport interfaces
- C. congestion on the switch inband path
- D. a failing NIC in an end device
- E. an overloaded shared segment
A collision domain is an area of a single LAN where end stations contend for access to the network because all end stations are connected to a shared physical medium. If two connected devices transmit onto the media at the same time, a collision occurs. When a collision occurs, a JAM signal is sent on the network, indicating that a collision has occurred and that devices should ignore any fragmented data associated with the collision. Both sending devices back off sending their data for a random amount and then try again if the medium is free for transmission.
Therefore, collisions effectively delay transmission of data, lowering the effective throughput available to a device. The more devices that are attached to a collision domain, the greater the chances of collisions; this results in lower bandwidth and performance for each device attached to the collision domain. Bridges and switches terminate the physical signal path of a collision domain, allowing you to segment separate collision domains, breaking them up into multiple smaller pieces to provide more bandwidth per user within the new collision domains formed.