Exam 200-301 topic 1 question 39 discussion

C is right Collision happens after 512 bits =64 byte =late collision

Collision occurs in the first 64 bytes A late collision occurs after the 512th bit (64th byte) of a frame has been transmitted by a device. Anything under 64byte frame is considered a runt.

If a collision is detected after the first 64 bytes (512 bits) of the frame are transmitted, it is considered a late collision

C is correct When a collision is detected by a station after it has sent the 512th bit of its frame, it is counted as a late collision. you can find it here exactly https://www.cisco.com/c/en/us/support/docs/interfaces-modules/port-adapters/12768-eth-collisions.html#topic4

C is correct

C. late collision is correct

Answer: C "The two devices that cause the late collision never see that each sends until after it puts the entire packet on the network. Late collisions are not detected by the transmitter until after the first 64 byte slot time. This is because they are only detected in transmissions of packets longer than 64 bytes."

In Ethernet networks, a late collision occurs when a collision is detected after the first 64 bytes of a frame have been transmitted. Late collisions often indicate issues with the network configuration or cabling. The interface counter that typically increments in response to late collisions is the "late collision" counter. Therefore, the correct answer is C. late collision.

C. late collision Explanation: In networking, a late collision occurs when a collision is detected after the first 64 bytes of a frame have been transmitted. Late collisions are typically indicative of a problem in the network, and they can lead to performance issues and frame loss. The other options are not applicable in the context described: A. runt Runt frames are frames that are too short to be valid. They are typically less than 64 bytes. B. collision Collisions typically occur during the initial part of the frame transmission. In Ethernet, collisions should be detected and handled within the first 64 bytes of a frame. D. CRC The CRC (Cyclic Redundancy Check) is a method used for error checking in frames. It is not directly related to the detection of collisions or late collisions.

B correct.... Runt: - < 64 byte CRC: cyclic redundancy check: crc errors increment the crc counter, but not increment collsion Late Collision: if transmit same time, and the collision not detected until after the 64 bytes of frames transmited so B correct

late collisions are not about detecting collisions after receiving a specific amount of data within a frame, but rather about detecting collisions that occur after a certain time has passed since the start of the frame transmission.

A late collision is a collision that occurs after the first 64 bytes of the frame have been transmitted. Late collisions typically indicate a problem with the network, such as excessive cable length or a misconfiguration. However, In this scenario, the collision is detected after the first 64 bytes of the frame have been received, not transmitted. Therefore, it is not considered a late collision.

C is right. "To allow collision detection to work properly, the period in which collisions are detected is restricted (512 bit-times). For Ethernet, this is 51.2us (microseconds), and for Fast Ethernet, 5.12us. For Ethernet stations, collisions can be detected up to 51.2 microseconds after transmission begins, or in other words up to the 512th bit of the frame. When a collision is detected by a station after it has sent the 512th bit of its frame, it is counted as a late collision." https://www.cisco.com/c/en/us/support/docs/interfaces-modules/port-adapters/12768-eth-collisions.html#topic4

Ethernet interfaces often have a general collision counter that increments whenever collisions are detected. This collision counter tracks the total number of collisions that occur during the transmission of frames. It does not differentiate between early collisions (which occur at the beginning of frame transmission) and late collisions (which occur after a specific point).

Ref: Late collision errors - Cisco Community Post by okopp “i think, that late collisions are caused collisions after first 64 bytes,this mean that the cable is too long. You could check cable length” A. runt Wrong answer. B. collision Wrong answer. C. late collision Correct answer. D. CRC Wrong answer.

If a device detects two stations transmitting frames at the same time after the first 64 bytes of the frame is received, this is an indication of a collision on the network. When a collision occurs, the device's interface counter for collisions will increment. The collision counter is a metric that is used to track the number of collisions that occur on a network interface. It is one of several counters that can be used to monitor the performance of a network interface and identify potential problems. Other counters that may be used to monitor the performance of a network interface include counters for transmitted and received frames, errors, and discards. If the collision counter is consistently high, it may indicate that there is a problem with the network, such as a high level of contention for network resources or a configuration issue. In this case, it may be necessary to troubleshoot the issue and take steps to reduce the number of collisions on the network. This could involve optimizing network configuration, adding additional network resources, or implementing other strategies to improve network performance.

Hate this question, since a spanish native speaker I am, always get confuse with "after" and "before" - that leads me to give the wrong answer 🥲