Based on the output, which Local Priority (LP) value will be applied to an incoming packet from interface 2/1/39 marked with DSCP 46 and CoS 7?

Question

Exhibits

Options

• ALocal Priority 1
• BLocal Priority 5
• CLocal Priority 7
• DLocal Priority 0

• A
  55% (26)
• B
  13% (6)
• C
  9% (4)
• D
  23% (11)

Explanation

Option A is correct because, based on the policy output shown, the interface is configured to trust DSCP over CoS, and DSCP 46 (Expedited Forwarding) maps to Local Priority 1 in the DSCP-to-LP mapping table - the CoS 7 value is effectively overridden by this trust policy.

Why the distractors are wrong:

• C (LP 7) is the trap answer - it's what CoS 7 would produce if CoS were trusted, but when DSCP takes precedence, CoS 7 is ignored.
• B (LP 5) corresponds to a different DSCP value in the mapping table, not DSCP 46.
• D (LP 0) is the lowest/default priority and does not correspond to DSCP 46 under any standard mapping shown in the output.

Memory tip: Think "DSCP Dominates" - when a QoS policy trusts DSCP, it always wins over CoS, no matter how high the CoS value is. On exam questions with conflicting DSCP and CoS markings, always check which trust mode is active and look up the DSCP-to-LP table in the given output, not the CoS value.

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