JNCIS-ENT High Availability Practice Question
During an audit of a Juniper EX4300 Virtual Chassis, you notice that member 1 and member 2 are connected via mixed 1G and 10G uplink ports. How does Junos handle mixed-speed Virtual Chassis port configurations?
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
✓
Virtual Chassis ports (VCPs) must be explicitly configured to match supported transceiver speeds, and mixing unsupported interface types will result in port initialization failure.
Junos EX series virtual chassis ports can be configured for specific speeds, but mismatched or unsupported port combinations will cause initialization failures or link errors depending on the platform.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Mixed speed links automatically drop to 1G to maintain backward compatibility without administrative intervention.
Why it's wrong here
VCPs do not auto-negotiate down like standard Ethernet access links unless explicitly supported by the optic type.
- ✗
Junos automatically load-balances stacking traffic across 1G and 10G links using weighted round-robin.
Why it's wrong here
Stacking ports operate at fixed configured speeds and do not dynamically load-balance like data LAGs.
- ✗
Only the 10G ports will carry control plane traffic while 1G ports are restricted to data transit.
Why it's wrong here
Stacking links carry both control plane and member data traffic indiscriminately.
- ✓
Virtual Chassis ports (VCPs) must be explicitly configured to match supported transceiver speeds, and mixing unsupported interface types will result in port initialization failure.
Why this is correct
Junos enforces strict hardware compliance for VCP connections; mismatched or unsupported transceiver types will fail to form a valid VC ring/chain.
About these practice questions
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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.