Question 380
A provider delivers a business VPN with negotiated expedited traffic. Observed: Packets leave the WAN interface with DSCP zero despite correct internal classification. What operational check best guards against this problem returning?
Explanation
Correct Answer
This control asks for the same recovery evidence (Captured outgoing frames retain the contracted DSCP markings) and flags recurrence of the same failure (Packets leave the WAN interface with DSCP zero despite correct internal classification). It targets the underlying issue, the egress rewrite rule does not map forwarding class and loss priority to the agreed codepoint, rather than a different service problem. The exact cadence must be agreed with operations.
Incorrect Answers
This gate monitors a different failure, the premium application suffers sustained loss before any low-priority flow is dropped. It would not detect the current problem: Packets leave the WAN interface with DSCP zero despite correct internal classification. The appropriate check requires captured outgoing frames retain the contracted DSCP markings.
It is valid for another service scenario but checks a new customer receives the same bandwidth guarantee as the largest existing customer. This case instead needs a gate for packets leave the wan interface with dscp zero despite correct internal classification and evidence that captured outgoing frames retain the contracted DSCP markings.
The proposed control is tied to a strict-priority queue has no effective cap or rate control, typically observed when other business queues starve whenever monitoring traffic floods. Here the target is the egress rewrite rule does not map forwarding class and loss priority to the agreed codepoint; monitor captured outgoing frames retain the contracted DSCP markings.