Exam 200-301 topic 1 question 75 discussion

reliability 255/255: When the input and output errors increase, they affect the reliability counter. This indicates how likely it is that a packet can be delivered or received succesfully. Reliability is calculated like this: reliability = number of packets / number of total frames. The value of 255 is the highest value meaning that the interface is very reliable at the moment. The calculation above is done every 5 minutes. So answer A is correct.

Why aren't people reading the question? It asks what is causing the issue not can you confirm the issue. Yes the reliability is down BUT WHY IS IT DOWN? That is the question not if there is an issue with reliability. We know there is a problem with reliability the question stated it and is confirmed by the reliability counter.

Value of 166/255: This value translates to approximately 65% reliability. This means that the interface is experiencing some issues that affect its ability to deliver or receive packets reliably

D is AI's response. Using the appropriate SFP modules as is the case here does not explicitly imply that the right fibre cable (single-mode or multi-mode) has been used for this point to point connection.

Error increments is the result of the reason, the question ask about the reason not the result or what happen , the answer D

it´s A When the input and output errors increase, they affect the reliability counter.

one cause will effect the interface errors and connectivity issues, therefore interface errors is not the cause. A is wrong.

A is not correct because it shows the effect of the problem and NOT the connectivity issue cause (that is what the question requires) B is not correct because, according to the TxLoad and RxLoad values (1/255) there is a very low usage. C is not correct because the used SFP are equals both side. The correct answer is D. Probably the sites distance is 5km but are connected with an OS1 single-modal type that support 10G on maximum distance of 2km.

physical issue

Can someone explain how its A? Thats the outcome isnt it?

Looks like a case of bad English to me, apparently operations moved out of the US.... A cause and effect are two different things, incrementing errors is an "effect" caused by some underlying issue, it can't be a "cause" by itself, incrementing errors is an equivalent to connectivity issues, it's nonsensical to define it as a cause for technician reporting it

A is result not the cause which is the one asked in the question.

Error increase is not the cause of the issue is the consequence/result of the issue!! A wrong cabel could be an issue...

I think A is the outcome, not the cause. So answer is B

I had had an confusing idea why A is correct, not B because of what the question says UNTIL I found rx/rxload indicatior show 1/255, which refers to very low amount of traffic you are sending/receiving. Therefore it's safely said that In/Output rate is not problematic at all.

A is correct

Shortly after SiteA was connected to SiteB over a new single-mode fiber path, users at SiteA report intermittent connectivity issues with applications hosted at SiteB. What is the cause of the intermittent connectivity issue? All parameters are equal between SiteA and SiteB, except for “reliability”. Ref: Cisco IOS Show Interface Explained - networklessons.com “… reliability 255/255: When the input and output errors increase, they affect the reliability counter. This indicates how likely it is that a packet can be delivered or received succesfully. Reliability is calculated like this: reliability = number of packets / number of total frames. The value of 255 is the highest value meaning that the interface is very reliable at the moment. The calculation above is done every 5 minutes. …” This means that “reliability = 255/255” indicates a perfectly working interface (SiteB), while “reliability = 166/255” means that the interface is experiencing transmission/reception errors (SiteA).