View Full Juniper JN0-364  Exam Dumps and Practice Test Dumps

 

Question: 21. Which Junos command is commonly used to display the current routing table?

1. show interfaces terse
   2. show route
   3. show configuration
   4. show chassis hardware

Correct Answer: 2. show route

Explanation:

The show route command displays routing information maintained by the Junos device. It can show active routes, protocol information, next hops, routing preferences, and other details useful for understanding how the router reaches destinations. Additional options can be used to examine specific routes, protocols, or routing tables. show interfaces terse is primarily used to review interface status and addressing, while show configuration displays the committed configuration hierarchy. show chassis hardware provides information about installed hardware components. For troubleshooting an unexpected forwarding decision, examining the routing table with show route is often an important step.

Question: 22. Which protocol is used by Junos devices to exchange routing information between autonomous systems?

1. OSPF
   2. IS-IS
   3. BGP
   4. LACP

Correct Answer: 3. BGP

Explanation:

Border Gateway Protocol, or BGP, is the primary routing protocol used to exchange reachability information between autonomous systems. BGP is classified as an exterior gateway protocol and is widely used by service providers, enterprises, and Internet networks. OSPF and IS-IS are interior gateway protocols normally used within an autonomous system. LACP is not a routing protocol; it negotiates and maintains link aggregation relationships. BGP uses attributes such as local preference, AS path, MED, and origin to influence route selection. Understanding the distinction between internal and external routing protocols is fundamental when troubleshooting inter-AS connectivity.

Question: 23. What does the Junos routing preference value primarily determine?

1. Which routing information source is preferred when multiple protocols provide a route to the same destination
   2. The bandwidth of a physical interface
   3. The number of BGP peers allowed on a router
   4. The MTU of an Ethernet frame

Correct Answer: 1. Which routing information source is preferred when multiple protocols provide a route to the same destination

Explanation:

Junos uses route preference to help determine which route should become active when multiple routing protocols provide routes to the same destination. A lower preference value is generally preferred over a higher value. This mechanism is different from metrics used internally by individual routing protocols. For example, OSPF has its own cost, while BGP has multiple path-selection attributes. Route preference allows Junos to compare routes from different sources at the routing-table level. When troubleshooting route selection, it is important to distinguish route preference from protocol-specific metrics and BGP attributes.

Question: 24. Which protocol is used to negotiate the bundling of Ethernet interfaces into an aggregated Ethernet link?

1. VRRP
   2. LACP
   3. BFD
   4. LLDP

Correct Answer: 2. LACP

Explanation:

The Link Aggregation Control Protocol, or LACP, is used to dynamically negotiate and maintain link aggregation between compatible devices. It allows multiple physical Ethernet links to operate as members of a logical aggregated connection. LACP helps verify that links are compatible and can participate in the aggregation group. VRRP provides gateway redundancy, BFD provides rapid failure detection, and LLDP exchanges information about directly connected devices. Link aggregation can improve availability and provide additional aggregate capacity, while LACP supplies the control mechanism used to establish and maintain the bundle.

Question: 25. Which OSPF metric is used to determine the preferred path toward a destination?

1. MED
   2. AS path length
   3. Local preference
   4. Cost

Correct Answer: 4. Cost

Explanation:

OSPF uses cost as its primary metric for calculating the shortest path toward destinations. Each OSPF interface can have an associated cost, and the SPF algorithm calculates paths by adding the costs of the links along each candidate path. The path with the lowest total cost is normally preferred. Local preference, MED, and AS path length are BGP-related concepts rather than OSPF path metrics. When troubleshooting OSPF route selection, checking interface costs and the resulting SPF topology can help explain why one path is preferred over another.

Question: 26. What is the purpose of an OSPF hello packet?

1. Advertise external BGP routes
   2. Carry user application data
   3. Discover and maintain relationships with OSPF neighbors
   4. Assign IPv4 addresses to interfaces

Correct Answer: 3. Discover and maintain relationships with OSPF neighbors

Explanation:

OSPF Hello packets are used to discover neighboring OSPF routers and maintain neighbor relationships. They contain information that helps routers determine whether they share compatible parameters, such as area membership, hello and dead intervals, and other configuration values. On networks where OSPF forms adjacencies, periodic Hello packets also help confirm that neighboring routers remain reachable. If Hello packets are not received within the configured dead interval, the neighbor can be considered unavailable. Problems involving mismatched OSPF parameters, interface configuration, or connectivity can therefore prevent successful neighbor formation.

Question: 27. Which Junos command is useful for displaying interface operational status and IP addressing in a compact format?

1. show route summary
   2. show interfaces terse
   3. show ospf database
   4. show system users

Correct Answer: 2. show interfaces terse

Explanation:

The show interfaces terse command provides a compact overview of interfaces, including administrative and operational status and configured protocol addresses. It is particularly useful during initial troubleshooting because it allows an administrator to quickly identify interfaces that are down or missing expected addresses. More detailed interface information can be obtained with show interfaces, while routing commands such as show route provide information about forwarding decisions. The terse output is valuable when checking many interfaces at once because it presents essential operational information without the volume of detail produced by a full interface-status command.

Question: 28. Which BGP session type is normally used between routers belonging to different autonomous systems?

1. Internal BGP
   2. External BGP
   3. OSPF adjacency
   4. IS-IS adjacency

Correct Answer: 2. External BGP

Explanation:

External BGP, or eBGP, is normally used to exchange routing information between routers belonging to different autonomous systems. Internal BGP, or iBGP, is used between BGP speakers within the same autonomous system. The distinction is important because eBGP and iBGP have different operational and route-propagation characteristics. OSPF and IS-IS are interior gateway protocols and do not represent BGP session types. When configuring eBGP, administrators must consider the peer’s autonomous system number, reachability, routing policy, and any required multihop or authentication settings.

Question: 29. Which IPv4 address is reserved for limited broadcast traffic?

1. 127.0.0.1
   2. 224.0.0.1
   3. 255.255.255.255
   4. 169.254.1.1

Correct Answer: 3. 255.255.255.255

Explanation:

The IPv4 address 255.255.255.255 is the limited broadcast address. Packets sent to this address are intended for all IPv4 hosts on the local broadcast domain and are not routed by routers. It is commonly associated with situations where a host needs to communicate with all local hosts without knowing the subnet’s directed broadcast address. 127.0.0.1 is the IPv4 loopback address, addresses in 224.0.0.0/4 are multicast addresses, and 169.254.0.0/16 is used for IPv4 link-local addressing. Recognizing these address categories helps during network troubleshooting.

Question: 30. What is the primary purpose of route redistribution?

1. Convert IPv4 addresses into MAC addresses
   2. Transfer routing information between different routing protocols or routing domains
   3. Increase Ethernet frame size
   4. Encrypt routing protocol packets

Correct Answer: 2. Transfer routing information between different routing protocols or routing domains

Explanation:

Route redistribution allows routes learned from one routing protocol or routing source to be introduced into another routing protocol. For example, an administrator might redistribute static routes or routes learned through one IGP into another routing domain. Redistribution must be designed carefully because it can introduce routing loops, suboptimal paths, excessive route information, or unexpected protocol interactions. Policy controls are often used to determine which routes are redistributed and how their attributes or metrics are handled. Redistribution does not perform address resolution, encryption, or Ethernet frame modification; its purpose is to exchange routing information between different sources.

Question: 31. Which Junos routing-instance type is commonly used to create a separate virtual routing table and routing domain?

1. Virtual Router
   2. Ethernet-switching
   3. Bridge domain
   4. Forwarding

Correct Answer: 1. Virtual Router

Explanation:

A Junos Virtual Router routing instance provides a separate routing table and routing domain on the same physical device. This allows routes and interfaces associated with one virtual routing environment to be logically separated from another. Such separation can be useful in multi-tenant networks, testing environments, or situations where independent routing domains are required. Other routing-instance types provide different functions, such as Layer 2 switching or specialized forwarding behavior. Routing instances are an important Junos mechanism for creating logical separation without requiring a separate physical router for every routing domain.

Question: 32. Which protocol is used to provide first-hop gateway redundancy for hosts on an IPv4 subnet?

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

Correct Answer: 3. VRRP

Explanation:

Virtual Router Redundancy Protocol, or VRRP, provides first-hop gateway redundancy by allowing multiple routers to participate in a virtual router configuration. Hosts can use a virtual IP address as their default gateway rather than relying on the physical address of a single router. If the active router becomes unavailable, another participating router can assume the forwarding role, helping maintain gateway availability. VRRP is different from routing protocols such as OSPF and BGP, which exchange route information. LACP provides link aggregation rather than gateway redundancy. VRRP is therefore commonly used to improve default-gateway resilience.

Question: 33. Which Junos command is most appropriate for viewing the OSPF neighbor relationships?

1. show bgp summary
   2. show ospf neighbor
   3. show interfaces terse
   4. show arp

Correct Answer: 2. show ospf neighbor

Explanation:

The show ospf neighbor command displays information about OSPF neighbors and their adjacency states. It can help administrators determine whether expected OSPF relationships have formed and whether neighbors have reached an operational state suitable for exchanging routing information. If a neighbor is missing or remains in an unexpected state, troubleshooting can proceed by checking interface status, addressing, area configuration, timers, authentication, and network connectivity. show bgp summary is used for BGP sessions, show arp displays IPv4-to-MAC resolution information, and show interfaces terse focuses on interface status.

Question: 34. Which routing protocol uses the Dijkstra Shortest Path First algorithm?

1. OSPF
   2. BGP
   3. RIP
   4. DHCP

Correct Answer: 1. OSPF

Explanation:

OSPF uses Dijkstra’s Shortest Path First algorithm to calculate the shortest paths through its link-state topology. Each OSPF router maintains a link-state database representing the topology of its area and runs the SPF calculation against that database. The resulting shortest-path tree is then used to determine routes. BGP uses a path-vector approach with multiple path attributes, while RIP uses a distance-vector mechanism based on hop count. DHCP is not a routing protocol at all. Understanding the algorithm used by a routing protocol helps explain its convergence behavior and route-selection process.

Question: 35. What is the purpose of an IPv4 subnet mask?

1. Identify the network and host portions of an IPv4 address
   2. Identify the Ethernet switch port of a host
   3. Encrypt an IPv4 packet
   4. Determine the BGP autonomous system number

Correct Answer: 1. Identify the network and host portions of an IPv4 address

Explanation:

An IPv4 subnet mask identifies which bits of an IPv4 address represent the network portion and which bits represent the host portion. This information allows devices to determine whether a destination is local to the same subnet or must be reached through a router. For example, a /24 prefix corresponds to the mask 255.255.255.0, leaving eight bits for host addressing. A subnet mask does not identify a physical switch port, provide encryption, or contain a BGP autonomous system number. Correct subnetting is essential for IP addressing, routing, and efficient network design.

Question: 36. Which BGP mechanism is commonly used to prevent the need for a full mesh of iBGP sessions?

1. Route reflector
   2. Stub area
   3. Link aggregation
   4. Virtual Router

Correct Answer: 1. Route reflector

Explanation:

A BGP route reflector reduces the requirement for a full mesh of internal BGP sessions. Instead of requiring every iBGP router to establish a session with every other iBGP router, selected routers can act as route reflectors and redistribute eligible routes to their clients. This simplifies BGP scaling within larger autonomous systems. Route reflection must be designed carefully because route-reflector behavior changes the normal iBGP propagation rules. Stub areas belong to OSPF, link aggregation combines physical Ethernet links, and a Virtual Router is a Junos routing-instance concept. Route reflection specifically addresses iBGP scalability.

Question: 37. Which protocol provides neighbor discovery functionality for IPv6 and replaces ARP functionality used by IPv4?

1. DHCPv4
   2. ICMPv6 Neighbor Discovery
   3. FTP
   4. STP

Correct Answer: 2. ICMPv6 Neighbor Discovery

Explanation:

IPv6 Neighbor Discovery operates through ICMPv6 and provides several functions that are associated with ARP and other IPv4 control mechanisms. It allows IPv6 nodes to discover neighboring devices, resolve link-layer addresses, detect duplicate addresses, and learn router information. Neighbor Solicitation and Neighbor Advertisement messages are central to this process. IPv4 uses ARP for address-to-MAC resolution, while IPv6 integrates these functions into the Neighbor Discovery framework. DHCPv4, FTP, and STP perform unrelated functions. Understanding ICMPv6 is important because blocking or filtering it incorrectly can disrupt essential IPv6 operations.

Question: 38. Which Junos command can be used to examine the detailed configuration hierarchy currently loaded on the device?

1. show route
   2. show interfaces terse
   3. show configuration
   4. show ospf neighbor

Correct Answer: 3. show configuration

Explanation:

The show configuration command displays the Junos configuration hierarchy from the configuration database. It allows administrators to inspect configured interfaces, protocols, policies, routing instances, system settings, and other configuration elements. This is different from operational commands such as show route or show interfaces terse, which report current operational state. When troubleshooting a configuration-related issue, comparing the intended configuration with the active operational state can help identify incorrect statements or missing settings. Junos also supports more targeted configuration displays by specifying hierarchy levels or configuration sections.

Question: 39. Which OSPF area is required as the backbone for communication between standard OSPF areas?

1. Area 1
   2. Area 10
   3. Area 100
   4. Area 0

Correct Answer: 4. Area 0

Explanation:

OSPF Area 0, also called the backbone area, provides the central inter-area routing structure in a hierarchical OSPF design. Standard non-backbone areas normally exchange inter-area routing information through the backbone. Area Border Routers connect other areas to Area 0 and advertise appropriate inter-area information. Proper backbone connectivity is therefore an important part of OSPF design. Although special configurations such as virtual links can address certain topology situations, they do not change the fundamental role of Area 0. Understanding the OSPF area hierarchy helps explain how routes move between different areas.

Question: 40. What is the primary function of a firewall filter on a Junos device?

1. Dynamically calculate OSPF shortest paths
   2. Aggregate Ethernet links
   3. Control traffic by matching packets against defined rules
   4. Assign IPv6 addresses automatically

Correct Answer: 3. Control traffic by matching packets against defined rules

Explanation:

A Junos firewall filter allows administrators to classify and control traffic by matching packet characteristics against configured terms and then applying actions. Match conditions can include information such as source or destination addresses, protocols, ports, and other packet fields. Actions can include accepting, discarding, counting, logging, or modifying certain forwarding behavior depending on the filter and platform. Firewall filters are therefore useful for traffic control, security policies, and packet classification. They are separate from routing protocols, link aggregation, and IPv6 address-autoconfiguration mechanisms, each of which serves a different networking function.