Mixed Deck — All JNCIA Topics Flashcards

Which approach is recommended for implementing security fundamentals changes?

Answer: Following a structured change management process with testing

A structured change management process with proper testing minimizes risk and ensures successful implementation.

What are the two main operational modes in the Junos OS CLI?

Answer: Operational and Configuration modes

The Junos OS CLI operates in operational mode for viewing system status and configuration mode for making changes to the system.

In Junos L3VPN, what is the function of a Route Target (RT)?

Answer: Controls which VRFs import which VPNv4 routes, implementing the VPN topology (full-mesh, hub-spoke, extranet)

Route Targets are BGP extended communities that control VRF route import and export. A VRF exports routes with certain RT values; other VRFs import routes matching specific RT values, defining VPN connectivity topology.

What command is used to enter configuration mode in Junos OS?

Answer: configure

The configure command switches the user from operational mode to configuration mode.

What is the purpose of a Junos CoS 'rewrite rule'?

Answer: To mark or re-mark DSCP/802.1p/MPLS EXP bits in packet headers as they egress an interface, propagating CoS information downstream

Rewrite rules in Junos CoS modify the DSCP, 802.1p, or MPLS EXP code points in outgoing packet headers based on the packet's forwarding class and loss priority, propagating CoS markings to downstream devices.

How should you document network configuration configurations?

Answer: Maintain up-to-date documentation in a centralized, accessible location

Centralized, accessible, and current documentation is essential for troubleshooting, disaster recovery, and knowledge sharing.

What is an LSP (Label Switched Path) in MPLS?

Answer: A unidirectional predetermined path through an MPLS network along which labeled packets are forwarded using swapped labels at each hop

An LSP is a unidirectional path from an ingress LSR to an egress LSR through one or more transit LSRs. Each LSR along the path has a label binding that maps the incoming label to an outgoing label and interface.

In Junos, which command shows the configuration difference between the active and candidate configuration?

Answer: show | compare

The 'show | compare' command in Junos configuration mode displays a diff between the current candidate configuration and the last committed (active) configuration.

What is the Junos 'forwarding table' and how does it differ from the routing table?

Answer: The forwarding table (FIB) contains only active best routes optimized for hardware lookup; the routing table (RIB) contains all learned routes

The RIB (Routing Information Base) contains all learned routes from all protocols. The FIB (Forwarding Information Base) in the PFE contains only the active best routes programmed for hardware forwarding.

Which approach is recommended for implementing data management changes?

Answer: Following a structured change management process with testing

A structured change management process with proper testing minimizes risk and ensures successful implementation.

How should you document implementation planning configurations?

Answer: Maintain up-to-date documentation in a centralized, accessible location

Centralized, accessible, and current documentation is essential for troubleshooting, disaster recovery, and knowledge sharing.

Which Junos feature provides stateful packet inspection for SRX devices?

Answer: Security policies with zones

On Junos SRX devices, security policies combined with security zones provide stateful inspection, tracking connection state for TCP, UDP, and ICMP sessions.

What is a prefix-list in Junos and how is it used?

Answer: A named list of IP prefixes used as a match condition in routing policies or firewall filters

A prefix-list in Junos is a named set of IP prefixes configured under policy-options. It can be referenced in routing policies (as 'route-filter') and firewall filters as a match condition.

What is 'fast reroute' (FRR) in Junos MPLS?

Answer: A protection mechanism that pre-computes backup paths for LSPs, enabling sub-50ms traffic rerouting upon link or node failure without waiting for IGP reconvergence

MPLS FRR pre-establishes detour or bypass LSPs before failures occur. When a protected link or node fails, traffic is immediately switched to the pre-computed backup path, typically within 50ms.

What is the Junos command to view detailed BGP route information including all path attributes?

Answer: show route [prefix] detail

'show route [prefix] detail' in Junos displays detailed route information including all BGP attributes: AS path, communities, LOCAL_PREF, MED, ORIGIN, and next-hop.

What is the fundamental principle behind troubleshooting methods in the context of Juniper Networks Certified Internet Associate?

Answer: Ensuring reliability, security, and optimal performance

Troubleshooting Methods in Juniper Networks Certified Internet Associate fundamentally aims to ensure system reliability, security, and optimal performance.

In Junos L3VPN, what is the purpose of the 'vrf-table-label' command?

Answer: Allocates a unique MPLS label per VRF routing table to enable MPLS-based forwarding for traffic arriving from the MPLS core toward CE devices

'vrf-table-label' in Junos allocates a per-VRF MPLS label that the egress PE uses to identify which VRF should receive incoming labeled traffic, enabling correct VPN traffic separation at the PE.

In a Junos firewall filter term, which keyword introduces the match conditions for the term?

Answer: from

The 'from' clause in a Junos firewall filter term defines the match conditions that a packet must satisfy for the term's actions to be applied.

What is the fundamental principle behind performance monitoring in the context of Juniper Networks Certified Internet Associate?

Answer: Ensuring reliability, security, and optimal performance

Performance Monitoring in Juniper Networks Certified Internet Associate fundamentally aims to ensure system reliability, security, and optimal performance.

What is the fundamental principle behind data management in the context of Juniper Networks Certified Internet Associate?

Answer: Ensuring reliability, security, and optimal performance

Data Management in Juniper Networks Certified Internet Associate fundamentally aims to ensure system reliability, security, and optimal performance.