JNCIS-ENT IS IS Practice Question
You have a Level 1/Level 2 router connecting two areas. How does it advertise itself to Level 1 routers?
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
✓
It advertises a default route using the ATT bit.
A Level 1/2 router sets the ATT bit in its Level 1 LSPs, signaling to Level 1 routers that it is an exit point to other areas.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
It requires a manual default-route configuration on all L1 routers.
Why it's wrong here
The ATT bit automates this process.
- ✗
It floods the entire Level 2 LSDB into the Level 1 area.
Why it's wrong here
Level 1 routers do not receive the full Level 2 database.
- ✗
It sends a specific inter-area TLV to all neighbors.
Why it's wrong here
IS-IS uses bits within the LSP header, not specific TLVs, to indicate attachment.
- ✓
It advertises a default route using the ATT bit.
Why this is correct
The ATT (Attached) bit is used to signal the presence of an inter-area path.
About these practice questions
This JNCIS-ENT question is part of Courseiva's 506-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official Juniper Networks exam blueprint
This JNCIS-ENT practice question is part of Courseiva's free Juniper Networks 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 JNCIS-ENT exam.