JNCIS-ENT Tunnels Practice Question
Which THREE characteristics distinguish GRE tunnels from IP-IP tunnels on Junos devices? (Choose three)
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
✓
GRE supports optional features like checksums and keys.
GRE supports multicast, has an optional checksum/key, and protocol type field, whereas IP-IP is simpler, supports protocol 4, and lacks multicast support.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
IP-IP tunnels require a specialized Routing Engine hardware card.
Why it's wrong here
Neither tunnel type strictly requires specialized non-standard hardware beyond normal PIC/routing support.
- ✓
GRE supports optional features like checksums and keys.
Why this is correct
GRE headers can include optional fields such as checksum and key identification.
- ✓
GRE uses IP protocol number 47 in the outer header.
Why this is correct
Protocol 47 is assigned to GRE, while IP-IP uses protocol 4.
- ✓
GRE supports encapsulation of multicast and broadcast traffic.
Why this is correct
GRE can encapsulate multicast packets, whereas IP-IP cannot.
- ✗
IP-IP tunnels inherently encrypt all transmitted data payloads.
Why it's wrong here
Neither GRE nor IP-IP provides native encryption.
About these practice questions
Courseiva writes every JNCIS-ENT question from scratch — 506 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 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.