350-501 Automation and Quality of Services Practice Question
In MPLS networks, the EXP bits are used for QoS. How are the 3-bit EXP values typically derived from DSCP markings at the ingress PE router?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The 3 most significant bits of DSCP are copied to EXP
A common mapping is to copy the three most significant bits of DSCP to EXP, which maps DSCP PHBs into corresponding EXP values.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
EXP is set by the egress PE router
Why it's wrong here
Incorrect; set at ingress.
- ✗
EXP is set to the same binary as the entire DSCP byte
Why it's wrong here
Incorrect; DSCP is 6 bits, EXP is 3 bits.
- ✓
The 3 most significant bits of DSCP are copied to EXP
Why this is correct
Correct; e.g., DSCP 46 (101110) -> EXP 5 (101).
- ✗
EXP is set to a static value per customer
Why it's wrong here
Incorrect; it is derived from DSCP.
Go deeper
Related to this question
About these practice questions
Courseiva writes every 350-501 question from scratch — 971 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 350-501 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-501 exam.