You are asked to configure a CoS weighted tail drop profile on your EX Series switch that causes
all traffic in the best effort queue to drop when the queue is 90 percent full.
Which configuration will accomplish this request?
A.
[edit class-of-service]
drop-profiles {
be_dropp {
fill-level 90;
drop-probability 100;
}
B.
[edit class-of-service]
drop-profiles {
be_dropp {
interpolate {
fill-level 90;
drop-probability 100;
}
C.
[edit class-of-service]
drop-profiles {
be_dropp {
fill-level 90;
}
D.
[edit class-of-service]
drop-profiles {
be_dropp {
fill-level 90;
drop-probability 90;
}
Should be A not C
Test, The thing here is that only EX4600 and QFX switches accept the command drop-probability (because they need to support WRED). That’s why I think that C is correct… anyways it’s a complicated question.
A is not Correct. fill-level value must be the same or higher than drop-probability.
The confusing for me is between C and D. I keep C as more correct, cause when we don´t define a value for drop-probability the system considers the same defined in fill-level.
Juniper has very similar key in these questions.
1 question is out of topic.
1 question is close, but uses wrong config options
2 questions usually are very close.
In this case A and D are very close. Applying the knowledge that fill-level must be the same or higher than drop-probability, I would choose D as correct answer, despite C is very close too, but C is not matching the answer key described above 😉
Do not apply this key generally, always apply your knowledge. This key can help you only in case you are totally surprised by the question!
Why do you think – the fill level must be same or higher than drop probability?
This configuration commited without errors:
[edit class-of-service drop-profiles]
+ Test {
+ interpolate {
+ fill-level 90;
+ drop-probability 100;
+ }
+ }
See:
http://www.juniper.net/documentation/en_US/junos12.3/topics/concept/cos-ex-series-tail-drop-understanding.html
On Juniper Networks EX Series Ethernet Switches, drop probability is implicitly set to 100 percent and it cannot be modified.
Answer C is the only correct answer.