Exam N10-008 topic 1 question 164 discussion

Actual exam question from CompTIA's N10-008

Question #: 164
Topic #: 1

A network administrator is reviewing the following metrics from a network management system regarding a switchport. The administrator suspects an issue because users are calling in regards to the switch port's performance:

Based on the information in the chart above, which of the following is the cause of these performance issues?

A. The connected device is exceeding the configured MTU.
B. The connected device is sending too many packets.
C. The switchport has been up for too long.
D. The connected device is receiving too many packets.
E. The switchport does not have enough CRCs.

Show Suggested Answer

Suggested Answer: A 🗳️

by kungfuseven at Dec. 12, 2022, 1:25 a.m.

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gunnyhwyusmc

Highly Voted 1 year ago

Selected Answer: A

If you are seeing Giants this the device is exceeding the default 1500 MTU size.

upvoted 11 times

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MitchF

Most Recent 7 months, 2 weeks ago

GPT picks (A): "Based on the provided metrics, the most likely cause of the performance issues is (A) The connected device is exceeding the configured Maximum Transmission Unit (MTU). The "Giants" metric of 2508 indicates that there are packets (frames) on the network that are larger than the allowed maximum size, which can lead to inefficiencies and performance problems. Exceeding the configured MTU can cause packet fragmentation or errors, leading to delays, retransmissions, and inefficiencies in the network. The other metrics provided, such as "CRCs" and "Output queue maximum," do not directly indicate the cause of the issue related to users' performance complaints. The "MDIX" being on refers to the auto-crossover feature for Ethernet cables and is not likely the cause of the performance issue. It's important to address the issue by ensuring that all devices on the network are configured with compatible MTU settings to avoid these performance problems."

upvoted 3 times

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[Removed]

1 year ago

A is the correct answer. MTU stands for "Maximum Transmission Unit," the maximum IP packet/Ethernet frame size that can traverse the network. For Ethernet networks, the MTU size is 1500 bytes, and anything larger than 1500 bytes is called a giant. According to the image, the connected device is outputting packets larger than 1500 bytes, which will cause Giants. Additionally, there are more packets outputted than packets inputted, which suggests that the switch has been dropping those packets. B and D are incorrect; this will cause network slowdowns with the overall switch and the transmitting device itself, not a specific interface on the switch. C has nothing to do with the slowdown. Many network devices today (especially Cisco devices) can have a very long uptime and still process and forward packets/frames. E is incorrect because you do not want CRCs. CRC is "Cyclic Redundancy Check," and it is the extra 4 bytes added to the end of an Ethernet frame for error-checking. If an Ethernet frame becomes corrupted, then the interface will show a CRC error, and it will drop the frame.

upvoted 4 times

Kessel

10 months, 3 weeks ago

That 2508 value associated with giants, is that the number of giants detected during the diagnostic, or it's the size in bytes of the giants detected?

upvoted 1 times

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kungfuseven

1 year, 3 months ago

A: Giants (see chart) In networks, a giant is a packet , frame , cell, or other transmission unit that is too large. Network protocols specify maximum and minimum sizes (and sometimes a single uniform size) for any transmission unit. For example, ATM packages all data into 53-byte cells. Any cell larger than that is discarded and recorded as a giant by network monitoring tools.