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

 

Question: 1. In OSPF, which LSA type is used by a router to describe its directly connected links within an area?

1. Type 3 LSA
   2. Type 1 LSA
   3. Type 5 LSA
   4. Type 7 LSA

Correct Answer: 2. Type 1 LSA

Explanation:

A Type 1 LSA, also called a Router LSA, is originated by every OSPF router and describes the router’s links, interfaces, neighbors, and associated link costs within an OSPF area. These LSAs are flooded throughout their originating area and form an important part of the link-state database used to calculate shortest paths. Type 3 LSAs are generated by ABRs to advertise networks between areas, while Type 5 LSAs carry external routes. Type 7 LSAs are used in NSSAs to represent external routes before they can be translated by an ABR. Understanding LSA roles is essential when troubleshooting OSPF topology and route propagation.

Question: 2. Which BGP attribute is primarily used to influence the preferred exit point from an autonomous system when multiple external routes are available?

1. MED
   2. Local preference
   3. Origin
   4. AS path

Correct Answer: 2. Local preference

Explanation:

Local preference is a BGP attribute used within an autonomous system to influence which exit point should be preferred for outbound traffic. A higher local-preference value is preferred over a lower value. Because local preference is propagated to internal BGP peers, it can consistently influence routing decisions throughout the AS. MED serves a different purpose and is generally used to suggest an entry point into an AS from a neighboring AS. AS path length is also considered during BGP route selection, but it does not provide the same internal exit-control function as local preference.

Question: 3. Which protocol is designed specifically to provide link-state routing for IP networks and uses a two-level hierarchy of Level 1 and Level 2 routers?

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

Correct Answer: 1. IS-IS

Explanation:

IS-IS is a link-state interior gateway protocol that uses a hierarchical design based on Level 1 and Level 2 routing. Level 1 routers primarily route within an IS-IS area, while Level 2 routers provide connectivity between areas. A router can operate as both Level 1 and Level 2. IS-IS builds a link-state database and uses the Shortest Path First algorithm to calculate routes. Unlike OSPF, IS-IS runs directly over Layer 2 rather than using IP as its transport protocol. These characteristics make IS-IS particularly important in large-scale service-provider environments.

Question: 4. What is the primary purpose of the OSPF designated router (DR) on a broadcast network?

1. Assign IP addresses to OSPF neighbors
   2. Replace the OSPF shortest-path calculation
   3. Provide default routing for all OSPF routers
   4. Reduce the number of OSPF adjacencies required on the segment

Correct Answer: 4. Reduce the number of OSPF adjacencies required on the segment

Explanation:

On broadcast multiaccess networks such as Ethernet, OSPF elects a designated router to reduce the number of full adjacencies that must be established. Without a DR, every router would need to form a full adjacency with every other router on the segment, creating a large number of relationships. Routers instead establish full adjacency with the DR and backup designated router, while other relationships are handled through the DR mechanism. The DR also originates a Type 2 Network LSA representing the multiaccess segment. This design significantly reduces OSPF flooding and adjacency overhead.

Question: 5. Which IPv6 routing protocol is the IPv6 version of OSPF and uses IPv6 link-local addresses for neighbor relationships?

1. OSPFv3
   2. OSPFv2
   3. RIPv2
   4. BGP-4

Correct Answer: 1. OSPFv3

Explanation:

OSPFv3 is the version of OSPF designed for IPv6 networks. OSPFv3 uses IPv6 link-local addresses for neighbor communication and relies on IPv6 protocol mechanisms rather than IPv4 addressing. The underlying link-state routing concepts remain familiar, including areas, LSAs, SPF calculations, and designated-router operation on broadcast networks. OSPFv2 is designed for IPv4. Although BGP can carry IPv6 reachability information through appropriate address families, it is not an IPv6-specific replacement for OSPF. When troubleshooting OSPFv3, verifying link-local connectivity, neighbor state, area configuration, and interface participation is important.

Question: 6. In BGP, what does the AS path attribute primarily provide?

1. The router’s interface bandwidth
   2. The number of active interfaces on a router
   3. The OSPF area associated with a route
   4. The sequence of autonomous systems through which a route has passed

Correct Answer: 4. The sequence of autonomous systems through which a route has passed

Explanation:

The AS path attribute records the sequence of autonomous systems through which a BGP route advertisement has traveled. It serves an important role in BGP route selection and loop prevention. When an external BGP route is advertised into another autonomous system, the advertising AS normally adds its AS number to the AS path. If a router receives a route containing its own AS number in the path, it can reject the route to prevent an inter-AS routing loop. AS path length can also influence BGP route selection, although it is only one of several attributes considered during the decision process.

Question: 7. Which Junos feature allows multiple physical Ethernet links to operate together as a single logical interface for increased capacity and redundancy?

1. VRRP
   2. Link aggregation
   3. Graceful restart
   4. BFD

Correct Answer: 2. Link aggregation

Explanation:

Link aggregation combines multiple physical Ethernet interfaces into a logical aggregated interface. This arrangement can provide increased aggregate bandwidth as well as redundancy because traffic can continue using remaining member links if one physical connection fails. On Junos devices, aggregated Ethernet interfaces are commonly used to connect switches, routers, and servers where higher availability or capacity is required. VRRP provides first-hop gateway redundancy, BFD detects forwarding failures rapidly, and graceful restart helps preserve routing during certain control-plane events. These technologies can complement link aggregation but perform different functions within a network.

Question: 8. What is the primary function of Bidirectional Forwarding Detection (BFD)?

1. Exchange routing policies between autonomous systems
   2. Assign addresses to IPv6 interfaces
   3. Detect forwarding-path failures rapidly
2. Encrypt routing protocol traffic

Correct Answer: 3. Detect forwarding-path failures rapidly

Explanation:

BFD is designed to provide rapid detection of forwarding-path failures between network devices. It uses lightweight control packets exchanged between participating systems and can detect failures much faster than waiting for normal routing-protocol timers to expire. BFD can be integrated with protocols such as OSPF, IS-IS, and BGP so that a detected failure can trigger faster routing convergence. BFD does not replace the routing protocol itself and does not provide encryption. Its purpose is failure detection, allowing the associated routing protocol or service to react quickly when connectivity is lost.

Question: 9. Which mechanism allows IPv6 hosts to automatically configure addresses using router advertisements without requiring a DHCPv6 server for address assignment?

1. SLAAC
   2. ARP
   3. NAT64
   4. STP

Correct Answer: 1. SLAAC

Explanation:

Stateless Address Autoconfiguration, or SLAAC, allows IPv6 hosts to automatically configure their addresses based on information received through Router Advertisement messages. A router advertises an IPv6 prefix, and the host uses that information to construct an address according to the applicable IPv6 addressing mechanism. SLAAC can operate without a DHCPv6 server being responsible for assigning the address itself. ARP is an IPv4 mechanism and is replaced by Neighbor Discovery in IPv6. NAT64 provides IPv6-to-IPv4 translation, while STP is a Layer 2 loop-prevention technology unrelated to IPv6 address configuration.

Question: 10. What is the main purpose of GRE tunneling?

1. Encapsulate one network protocol inside another IP packet
   2. Provide Ethernet switching between VLANs
   3. Assign IPv4 addresses dynamically
   4. Replace BGP route advertisements

Correct Answer: 1. Encapsulate one network protocol inside another IP packet

Explanation:

Generic Routing Encapsulation, or GRE, creates a logical tunnel by encapsulating an original packet inside another IP packet. This allows traffic to traverse an intermediate IP network as if it were being transported through a logical point-to-point connection. GRE can be used for connecting networks, carrying routing protocols across an IP infrastructure, or creating logical paths between endpoints. GRE itself does not provide encryption, so additional security mechanisms may be required when confidentiality is necessary. GRE troubleshooting commonly involves checking tunnel endpoint reachability, routing to the tunnel endpoints, tunnel status, and the routes using the tunnel.

Question: 11. Which BGP attribute is commonly used to indicate a preferred path for traffic entering an autonomous system from an external neighbor?

1. Local preference
   2. Origin
   3. MED
   4. Router ID

Correct Answer: 3. MED

Explanation:

The Multi-Exit Discriminator, or MED, can be used by one autonomous system to indicate a preferred entry point for traffic entering that autonomous system from a neighboring autonomous system. In general, a lower MED is preferred when comparing otherwise eligible routes from the same neighboring AS. MED is therefore useful when an organization has multiple connections to the same external AS and wants to influence which connection that neighbor uses. MED should not be confused with local preference, which is primarily used internally to influence outbound path selection. Actual BGP selection behavior depends on the complete route-selection process and configuration.

Question: 12. Which OSPF area type is designed to prevent external Type 5 LSAs from being flooded into the area?

1. Backbone area
   2. Stub area
   3. Transit area
   4. Standard area

Correct Answer: 2. Stub area

Explanation:

An OSPF stub area is designed to reduce the amount of external routing information that must be carried inside the area. Type 5 LSAs, which represent external routes, are not flooded into a traditional stub area. Instead, a default route can be advertised by the ABR so that routers inside the stub area can reach destinations outside the area without maintaining detailed external route information. Stub areas are therefore useful when detailed external routing information is unnecessary. Other specialized area types, such as totally stubby areas and NSSAs, provide different behaviors for controlling inter-area and external routing information.

Question: 13. In Junos, which routing table is normally used for IPv4 unicast routes?

1. inet.0
   2. inet6.0
   3. mpls.0
   4. iso.0

Correct Answer: 1. inet.0

Explanation:

The inet.0 routing table is the primary routing table for IPv4 unicast routes in Junos. It contains routes learned through protocols such as OSPF, IS-IS, BGP, static routing, and directly connected interfaces when those routes belong to the IPv4 unicast family. The inet6.0 table is used for IPv6 unicast routing. Other routing tables serve specialized purposes, such as MPLS forwarding information or ISO routing. When troubleshooting IPv4 routing on a Junos device, commands such as show route are commonly used to inspect entries in inet.0 and understand how the device selects a destination route.

Question: 14. Which BGP feature allows a router to advertise multiple paths toward the same destination for load balancing?

1. Route reflection
   2. Route damping
   3. MED
   4. Multipath

Correct Answer: 4. Multipath

Explanation:

BGP multipath allows multiple eligible BGP paths to the same destination to be installed or used for forwarding when the necessary conditions are satisfied. This can provide load sharing across multiple paths instead of relying on only one selected BGP route. The exact behavior depends on configuration and whether the candidate paths meet the requirements for multipath installation. Route reflection is primarily used to reduce the need for a full iBGP mesh. Route damping addresses route instability, while MED is a BGP path-selection attribute. Multipath is therefore the feature directly associated with using multiple BGP paths for forwarding.

Question: 15. Which IS-IS level is primarily responsible for routing within a single IS-IS area?

1. Level 2
   2. Level 3
   3. Level 1
   4. Level 0

Correct Answer: 3. Level 1

Explanation:

IS-IS Level 1 routing is primarily concerned with routing within an individual IS-IS area. Level 1 routers maintain information about destinations within their area and use Level 2 routers to reach destinations outside the local area. Level 2 routing provides inter-area connectivity and forms the backbone between IS-IS areas. Some routers can operate as both Level 1 and Level 2, allowing them to participate in both intra-area and inter-area routing. Understanding these levels is important when troubleshooting IS-IS route propagation because a route may be present at one level while unavailable at another.

Question: 16. What is the primary purpose of Graceful Routing Engine Switchover (GRES) on a Junos device with redundant Routing Engines?

1. Provide Layer 2 VLAN tagging
   2. Allow control-plane switchover while helping preserve forwarding operations
   3. Replace the routing table with a static configuration
   4. Encrypt traffic between Routing Engines

Correct Answer: 2. Allow control-plane switchover while helping preserve forwarding operations

Explanation:

GRES is a Junos high-availability mechanism designed for systems with redundant Routing Engines. It allows control to transition between Routing Engines while helping preserve packet forwarding through the Packet Forwarding Engine during the switchover. GRES by itself is different from features that synchronize protocol state or routing information between Routing Engines. Additional high-availability mechanisms may be used when more extensive state preservation is required. GRES does not provide encryption or VLAN functionality. When designing redundant Junos systems, understanding the distinctions among GRES, graceful restart, nonstop active routing, and nonstop bridging is important.

Question: 17. Which protocol is specifically designed to detect failures between two directly connected network devices and can operate independently of a particular routing protocol?

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

Correct Answer: 4. BFD

Explanation:

Bidirectional Forwarding Detection is designed specifically for rapid detection of forwarding failures between neighboring devices. It is not itself an interior or exterior routing protocol. Instead, BFD can work with multiple routing protocols and other network functions so that they can react quickly when a forwarding path becomes unavailable. This separation allows failure detection to operate independently from the normal convergence timers of protocols such as OSPF, IS-IS, or BGP. BFD is particularly useful where rapid failure detection is important. The actual BFD session depends on the participating devices and supported configuration.

Question: 18. In OSPF, what is the primary purpose of an area border router (ABR)?

1. Connect multiple OSPF areas and exchange routing information between them
   2. Assign MAC addresses to Ethernet interfaces
   3. Encrypt OSPF packets
   4. Replace all external BGP routes

Correct Answer: 1. Connect multiple OSPF areas and exchange routing information between them

Explanation:

An OSPF Area Border Router connects one OSPF area to another and maintains appropriate link-state information for the areas to which it is attached. The ABR plays a key role in inter-area route exchange and originates summary or inter-area LSAs to advertise reachability between areas. A common design places the backbone Area 0 at the center of the OSPF hierarchy. An ABR does not assign MAC addresses or encrypt OSPF traffic. Its main function is to provide the routing boundary between OSPF areas while participating in the necessary link-state calculations and advertisements.

Question: 19. Which IPv6 address range is used for link-local addresses?

1. 2000::/3
   2. FC00::/7
   3. FE80::/10
   4. FF00::/8

Correct Answer: 3. FE80::/10

Explanation:

IPv6 link-local addresses use the FE80::/10 prefix. These addresses are automatically associated with IPv6-enabled interfaces and are intended for communication on the local link rather than across routed networks. Link-local addressing is fundamental to IPv6 neighbor communication and is also used by protocols such as OSPFv3. The 2000::/3 range is used for global unicast addressing, FC00::/7 is associated with unique local addresses, and FF00::/8 is reserved for multicast addresses. When troubleshooting IPv6 routing protocols, verifying link-local connectivity is often an important first step.

Question: 20. Which Junos high-availability feature is specifically intended to maintain routing protocol state during a Routing Engine switchover?

1. Nonstop active routing (NSR)
   2. Link aggregation
   3. Virtual Router Redundancy Protocol
   4. Generic Routing Encapsulation

Correct Answer: 1. Nonstop active routing (NSR)

Explanation:

Nonstop active routing, or NSR, is designed to maintain routing protocol state across a Routing Engine switchover, reducing the need for routing protocols to restart and reestablish their sessions. This can help minimize routing disruption during certain control-plane failures or maintenance events. NSR is different from GRES, which focuses on maintaining forwarding while control transitions between Routing Engines. VRRP provides gateway redundancy between devices, while link aggregation combines physical links and GRE provides tunneling. Understanding the specific purpose of each high-availability technology is important when designing resilient Junos-based networks.