JNCIS-ENT Protocol Independent Routing Practice Question
An engineer configures a static route pointing to an interface rather than an IP address. What potential issue can occur with interface-based static routes on multi-access Ethernet networks in Junos OS?
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 router will generate an ARP request for every destination IP, potentially exhausting ARP cache.
On multi-access networks (like Ethernet), pointing a static route directly to an interface causes the router to ARP for every destination IP address it receives, potentially exhausting ARP tables (Proxy ARP behavior or ARP storm).
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The packet forwarding engine will crash due to unresolvable MAC addresses.
Why it's wrong here
The PFE will not crash; it will simply drop or fail to resolve frames if ARP fails.
- ✗
The static route will immediately enter a hidden state due to missing next-hop IP.
Why it's wrong here
Junos allows interface routes, but handles them via ARP resolution.
- ✗
BGP will automatically re-advertise the interface route into external ASNs.
Why it's wrong here
Static routes are not automatically redistributed into BGP without a policy.
- ✓
The router will generate an ARP request for every destination IP, potentially exhausting ARP cache.
Why this is correct
Interface routes on Ethernet cause the router to treat all destination IPs as directly connected, leading to excessive ARP traffic.
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.