View Full Juniper JN0-253 Exam Dumps and Practice Test Dumps.

 

Question 81

What is the primary function of Juniper Mist Service Level Expectations (SLEs)?

1. Tracking client experience metrics
2. Encrypting Wi-Fi payload data
3. Managing switch PoE power limits
4. Routing BGP prefix updates

Correct Answer: 4

Explanation

Service Level Expectations serve as the essential foundation for measuring actual user experience within the Mist architecture. Instead of relying solely on infrastructure metrics, SLEs track client-centric parameters like connection time, throughput, roaming performance, and coverage. Each metric is evaluated continuously against predefined thresholds, enabling administrators to isolate whether connection failures stem from DHCP starvation, DNS latency, authentication timeouts, or physical signal degradation. This shifts the operational paradigm from device monitoring to true client tracking, empowering IT teams to resolve bottlenecks efficiently.

Question 82

Which command displays the active IP routing table on a Junos routing device?

1. show ospf neighbor
2. show interface
3. show route
4. show chassis hardware

Correct Answer: 3

Explanation

The show route command is the primary operational tool used by network engineers to inspect active routing table entries, destination prefixes, next-hop addresses, and protocol preferences on Junos platforms. When executed, it outputs comprehensive reachability details calculated by routing protocol daemons running on the routing engine. Verifying this output allows administrators to confirm active paths, troubleshoot unreachable subnets, and analyze route selection preferences across enterprise network architectures.

Question 83

What role does a Junos candidate configuration play prior to commit execution?

1. Disabling all physical ports
2. Staging changes safely in memory
3. Overwriting flash memory instantly
4. Reboots routing engine hardware

Correct Answer: 2

Explanation

In Junos OS, the candidate configuration acts as a secure staging buffer where administrators can make, edit, and test configuration modifications without affecting the active production environment. This isolated workspace prevents accidental syntax errors or disruptive changes from disrupting ongoing network operations immediately. Once edits are verified, executing a commit command applies the candidate changes to the running database, ensuring robust operational stability and safe administrative control.

Question 84

Which security feature prevents unauthorized network access based on device physical MAC addresses?

1. Link aggregation
2. Static ARP mapping
3. Port security
4. NTP synchronization

Correct Answer: 3

Explanation

Port security is a robust layer two access control feature that restricts input on switch interfaces by limiting and recording the physical MAC addresses of connected devices. Administrators can configure specific maximum MAC address limits per port. If an unknown device connects or the limit is exceeded, the switch triggers configured violation modes—such as restricting traffic or shutting down the interface—protecting the network from unauthorized endpoint attachments and spoofing attempts.

Question 85

What is the main purpose of configuring NTP on enterprise network devices?

1. Encrypting administrative passwords
2. Compressing streaming telemetry data
3. Allocating dynamic IP addresses
4. Synchronizing system clocks accurately

Correct Answer: 4

Explanation

Network Time Protocol is critical for maintaining precise clock synchronization across all switches, routers, and access points within an enterprise deployment. Accurate timekeeping ensures that event logs, security audit trails, and cloud streaming telemetry align chronologically. This synchronization enables automated artificial intelligence platforms like Marvis to correlate diagnostic events accurately during multi-domain troubleshooting and root cause analysis workflows.

Question 86

Which protocol automates the bundling of multiple physical Ethernet links into a single logical pipe?

1. OSPF
2. LACP
3. BGP
4. RSTP

Correct Answer: 2

Explanation

Link Aggregation Control Protocol, standardized under IEEE 802.3ad, enables administrators to bundle several physical Ethernet interfaces together to act as a single logical connection. LACP automates member link health checks, increases total available bandwidth between switches beyond single cable limits, and provides instantaneous failover redundancy if an individual physical cable or transceiver fails. Traffic is intelligently hashed across member links for balanced utilization.

Question 87

What action does a Junos commit confirmed command perform if connection verification fails?

1. Erases all system flash memory
2. Upgrades the operating image
3. Automatically rolls back changes
4. Shuts down the device permanently

Correct Answer: 3

Explanation

The commit confirmed command acts as an essential safety mechanism designed to prevent network engineers from locking themselves out of remote devices due to erroneous configuration changes. When executed, the device applies configuration changes temporarily while starting a countdown timer. If the administrator loses network connectivity and fails to verify changes before the timer expires, Junos automatically rolls back the configuration to the previous stable state, restoring management access instantly.

Question 88

Which component of the Mist platform provides automated anomaly detection using machine learning?

1. Wired Assurance engine
2. Marvis Assistant
3. Mist Edge proxy
4. Analytics data warehouse

Correct Answer: 2

Explanation

Marvis is the virtual network assistant built directly into the Mist AI platform designed to simplify complex enterprise troubleshooting and daily operations. It leverages machine learning algorithms to continuously monitor live telemetry data, identify abnormal behaviors instantly, and pinpoint exact root causes across wireless, wired, and security domains. By fully automating anomaly detection workflows, Marvis reduces operational overhead, minimizes mean time to resolution, and provides proactive actionable insights to network administrators.

Question 89

What is the primary function of DHCP Snooping in enterprise switching architectures?

1. Routing inter-subnet traffic
2. Encrypting wireless user data
3. Generating network traffic logs
4. Blocking rogue DHCP servers

Correct Answer: 4

Explanation

DHCP Snooping functions as a foundational layer two security mechanism that differentiates between trusted port connections linked to legitimate corporate DHCP servers and untrusted ports facing client endpoints. By tracking dynamic IP-to-MAC address assignments, the switch builds a secure binding database. If an unauthorized rogue device attempts to connect a fake DHCP server to an untrusted access port and distribute malicious gateway configurations, the switch drops rogue offer packets instantly.

Question 90

Which protocol acts as the control plane for EVPN in modern data center interconnect fabrics?

1. Spanning tree protocol
2. Multiprotocol BGP
3. OSPF version 2
4. Static routing tables

Correct Answer: 2

Explanation

Ethernet Virtual Private Network relies on Multiprotocol Border Gateway Protocol as its foundational control plane protocol. EVPN uses BGP to distribute layer two MAC addresses and layer three routing reachability information across standard IP core networks. This decouples virtual workloads from physical topologies, allowing seamless layer two mobility across disparate data centers while maintaining multi-tenancy, localized ARP suppression, and optimized multi-path forwarding without traditional spanning tree limitations.

Question 91

What does a solid green LED status indicator typically signify on a Mist access point?

1. Critical hardware failure
2. Normal cloud connection
3. Firmware download active
4. BLE beacon mode active

Correct Answer: 2

Explanation

On Juniper Mist access points, integrated multi-color LED status indicators provide immediate visual feedback regarding operational health and connectivity. A solid green indicator typically signals that the access point has successfully booted, established a stable connection with the cloud management platform, and is operating normally. This visual cue confirms to on-site personnel that wireless services are active and communicating properly with the centralized management infrastructure without errors.

Question 92

Which Juniper switch feature combines multiple physical switches into a single logical routing entity?

1. Storm control
2. Firewall filters
3. Port security
4. Virtual Chassis

Correct Answer: 4

Explanation

Virtual Chassis technology allows multiple interconnected EX Series switches to function as a single unified logical device, significantly simplifying network management and topology design. Instead of managing individual switch IP addresses and configuration files separately, administrators interact with a single control plane across the stack. This architecture provides high availability through distributed link aggregation groups, seamless failover mechanisms, and simplified spanning tree topologies by eliminating bridge loops.

Question 93

What is the primary benefit of deploying cloud-native access points?

1. Elimination of local controllers
2. Manual radio tuning control
3. Increased copper cable lengths
4. Local flash log storage

Correct Answer: 1

Explanation

Cloud-native access points are engineered from the ground up to interface directly with scalable cloud management platforms, bypassing the need for traditional on-premises hardware controllers or physical appliances. They offload control plane intelligence, analytics collection, and machine learning computations directly to the cloud. This modern architecture ensures seamless scalability, automated zero-touch provisioning, rapid software updates, and instant global access to telemetry databases without complex local management hierarchies.

Question 94

Which Junos command displays detailed diagnostic statistics for a specific interface?

1. show route summary
2. show interface extensive
3. show ospf neighbor
4. show bgp summary

Correct Answer: 2

Explanation

The show interface extensive command provides a comprehensive, itemized diagnostic output for physical and logical interfaces configured on a Junos routing or switching platform. It displays comprehensive operational statistics including packet counts, byte rates, error counters, CRC drops, queue drops, physical duplex settings, encapsulation types, and specific hardware transceiver diagnostics. This command is an indispensable asset for network engineers troubleshooting physical layer issues or interface congestion.

Question 95

What is the primary objective of implementing OSPF authentication?

1. Compressing routing updates
2. Accelerating packet forwarding
3. Encrypting transit payloads
4. Securing routing adjacencies

Correct Answer: 4

Explanation

OSPF authentication mechanisms are designed specifically to secure routing protocol exchanges by verifying the identity of neighboring routers before establishing adjacencies. By implementing plaintext passwords or cryptographic MD5/SHA keys on OSPF interfaces, network administrators prevent rogue devices or malicious actors from injecting false link-state advertisements or participating in the routing domain. While OSPF authentication does not encrypt user data payloads, it strictly safeguards the integrity and authenticity of the control plane.

Question 96

Which standard defines Rapid Spanning Tree Protocol for fast convergence?

1. IEEE 802.3ad
2. IEEE 802.1w
3. IEEE 802.1Q
4. IEEE 802.1X

Correct Answer: 2

Explanation

Rapid Spanning Tree Protocol is standardized globally under IEEE 802.1w, offering significant convergence speed improvements over legacy IEEE 802.1D bridging standards. RSTP introduces explicit proposal-agreement handshakes between neighboring switches, allowing designated and root ports to transition directly into forwarding states almost instantaneously when link changes occur. This eliminates lengthy listening and learning delays, preventing broadcast storms and bridge loops while maintaining uninterrupted application session uptime.

Question 97

What role does Mist Edge perform in remote branch office deployments?

1. Local web caching
2. Firewall inspection
3. Tunnel aggregation
4. DHCP server routing

Correct Answer: 3

Explanation

Mist Edge is expertly engineered to extend corporate campus fabrics and provide distributed tunnel aggregation capabilities for remote access point deployments. It terminates secure IPsec or GRE tunnels originating from remote branch access point deployments right back to the central datacenter or enterprise campus edge. This allows network administrators to maintain centralized tunneling policies, dynamic VLAN mapping, and secure traffic steering while still leveraging decentralized wireless architectures across various branch offices seamlessly.

Question 98

Which CLI command discards uncommitted changes in Junos configuration mode?

1. rollback zero
2. discard changes
3. clear candidate
4. exit abandon

Correct Answer: 2

Explanation

In Junos OS, the discard changes command is used within configuration mode to abandon any pending modifications made to the active candidate configuration database without applying them. This is an essential safety feature when an administrator tests complex configuration scenarios or makes inadvertent syntax edits and wishes to revert the candidate database back to the exact state of the current running configuration. Once executed, the editor discards the staging buffer and preserves system stability.

Question 99

What is the core function of Mist Radio Resource Management?

1. Filtering web payload URLs
2. Encrypting management frames
3. Allocating IP leases dynamically
4. Optimizing channels and power

Correct Answer: 4

Explanation

Radio Resource Management is an automated feature designed to continuously monitor wireless RF environments and dynamically adjust access point power levels and channel assignments. In dense enterprise deployments, RRM mitigates co-channel interference, balances client load across available access points, and ensures optimal coverage blankets. By reacting intelligently to real-time environmental changes, RRM maintains high wireless performance without requiring manual RF site survey adjustments or constant human intervention.

Question 100

Which feature enables Mist access points to track indoor client devices and physical assets?

1. Infrared motion detectors
2. Bluetooth Low Energy array
3. Ultrasonic audio receivers
4. High-frequency radar units

Correct Answer: 2

Explanation

Mist access points feature a patented multi-element Bluetooth Low Energy antenna array that enables highly accurate indoor location services and asset tracking. Unlike traditional single-antenna Bluetooth solutions, the virtual BLE array listens to beacons from client devices and computes precise locations using advanced machine learning algorithms. This capability supports proximity messaging, asset tracking, and indoor wayfinding without requiring dedicated hardware location overlay beacons or complicated physical site calibrations.