350-501 Networking Practice Question
Which IS-IS TLV is used to carry Traffic Engineering (TE) information such as link bandwidth and TE metric in modern SP networks?
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
✓
TLV 22 (extended IS reachability)
IS-IS TE extensions use sub-TLVs within the extended IS reachability TLV (type 22). Specifically, TLV 135 (extended IP reachability) carries wide metrics, but TE information is carried in the extended IS reachability TLV (type 22) with sub-TLVs. The question asks for the TLV that carries TE info; the correct answer is the extended IS reachability TLV (type 22).
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
TLV 22 (extended IS reachability)
Why this is correct
Correct. TLV 22 carries extended IS reachability with sub-TLVs for TE.
- ✗
TLV 128 (IP reachability)
Why it's wrong here
TLV 128 is for IP internal reachability, not TE.
- ✗
TLV 135 (extended IP reachability)
Why it's wrong here
TLV 135 carries IP reachability with wide metrics, not TE information.
- ✗
TLV 1 (area addresses)
Why it's wrong here
TLV 1 carries area addresses, not TE.
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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.