Refer to the exhibit. The link between PC1 and the switch is up, but it is performing poorly. Which interface condition is causing the performance problem?
A.
There is an issue with the fiber on the switch interface.
The answer is B.
The PC's port runs in full duplex, while the Fa0/1 port on the switch is in auto-negotiate mode.
This results in a duplex mismatch that causes the switchport to operate as half-duplex, which culminates in poor performance on the link.
"A duplex mismatch occurs when two connected devices are configured in different duplex modes.
This may happen, for example, if one is configured for autonegotiation while the other one has a fixed mode of operation that is full duplex (no autonegotiation). In such conditions, the autonegotiation device correctly detects the speed of operation, but is unable to correctly detect the duplex mode.
As a result, it sets the correct speed but assumes half-duplex mode.
When a device is operating in full duplex while the other one operates in half duplex, the connection works reliably only at a very low throughput."
Reference: https://en.wikipedia.org/wiki/Autonegotiation#Duplex_mismatch
Because, CISCO and IEEE have 2 conventions, from which one says: if autonegotiate is on, then you are supposed to use the lower speed. However, it is not true for the second one regarding duplex. The second convention states that if the speed is either 10 or 100, use Half Duplex. So in other words, on PC you have Full Duplex ( manually set ), but on the switch is Half ( due to the 2nd convention ). This causes a duplex mismatch.
Answer is B.
One of the most common causes of performance issues on 10/100 Mb Ethernet links occurs when one port on the link operates at half-duplex while the other port operates at full-duplex. This occurs when one or both ports on a link are reset and the auto-negotiation process does not result in both link partners with the same configuration. It also can occur when users reconfigure one side of a link and forget to reconfigure the other side. Both sides of a link must have auto-negotiation on, or both sides must have it off. Cisco recommends to leave auto-negotiation on for those devices compliant with 802.3u.
Ref: Autonegotiation – Wikipedia
“…
Duplex mismatch
A duplex mismatch occurs when two connected devices are configured in different duplex modes. This may happen, for example, if one is configured for autonegotiation while the other one has a fixed mode of operation that is full duplex (no autonegotiation). In such conditions, the autonegotiation device correctly detects the speed of operation, but is unable to correctly detect the duplex mode. As a result, it sets the correct speed but assumes half-duplex mode.
When a device is operating in full duplex while the other one operates in half duplex, the connection works reliably only at a very low throughput.
…”
I'm not sure B is the right answer. Switch port is configured in auto mode, so it would be able to negotiate to full duplex. Why can not be C the right answer?
This section is not available anymore. Please use the main Exam Page.200-301 Exam Questions
Log in to ExamTopics
Sign in:
Community vote distribution
A (35%)
C (25%)
B (20%)
Other
Most Voted
A voting comment increases the vote count for the chosen answer by one.
Upvoting a comment with a selected answer will also increase the vote count towards that answer by one.
So if you see a comment that you already agree with, you can upvote it instead of posting a new comment.
Jbcrggddfhh
Highly Voted 3 years agoPyoJH
Highly Voted 1 year, 5 months agoboog
Most Recent 2 months, 3 weeks agoCiprian2410
1 month, 1 week agoskullomania
7 months ago[Removed]
7 months ago[Removed]
1 year agoNmk3216
1 year, 5 months agoskullomania
1 year, 6 months agohp2wx
2 years, 9 months agoZUMY
2 years, 11 months ago