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

Question: 101. Which Junos command displays the current BGP routing table entries?

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

Correct Answer: 2. show route protocol bgp

Explanation:

The show route protocol bgp command displays routes learned through BGP in the Junos routing table. It is useful when troubleshooting BGP route learning, verifying imported prefixes, and determining which BGP routes are currently installed. The show bgp summary command provides session and peer information rather than the complete set of BGP-learned routes. By examining routes learned from BGP, an administrator can verify whether routing policies and BGP sessions are producing the expected routing information.

Question: 102. Which BGP attribute is normally used to identify the originating autonomous system path and help prevent routing loops?

1. MED
   2. Local Preference
   3. AS_PATH
   4. NEXT_HOP

Correct Answer: 3. AS_PATH

Explanation:

The BGP AS_PATH attribute records the autonomous systems that a route advertisement has traversed. When a BGP router receives a route containing its own autonomous system number in the AS_PATH, it can reject the route as a potential routing loop. AS_PATH is also used as one of the factors in BGP path selection, with shorter paths generally preferred when comparing otherwise suitable routes. This makes the attribute important for both loop prevention and route selection.

Question: 103. What is the primary purpose of an OSPF Router LSA (Type 1)?

1. To advertise external routes from another routing protocol
   2. To describe the links and interfaces of a router within an OSPF area
   3. To advertise routes between autonomous systems
   4. To identify the designated router on a LAN only

Correct Answer: 2. To describe the links and interfaces of a router within an OSPF area

Explanation:

An OSPF Type 1 Router LSA is originated by every OSPF router and describes that router’s links, interfaces, and associated OSPF information within an area. Other routers use these LSAs to build a common link-state database and calculate shortest paths using the SPF algorithm. Type 1 LSAs are area-specific and are not directly used to advertise external routes. Type 5 LSAs serve the purpose of describing external routes introduced into an OSPF domain.

Question: 104. Which Junos command is commonly used to verify OSPF neighbor relationships?

1. show ospf neighbor
   2. show route forwarding-table
   3. show bgp summary
   4. show ethernet-switching table

Correct Answer: 1. show ospf neighbor

Explanation:

The show ospf neighbor command displays information about OSPF neighbor relationships, including neighbor IDs, interface information, state, and adjacency details. It is one of the primary commands used to troubleshoot OSPF adjacency problems. States such as Full indicate that an adjacency has successfully reached the database synchronization stage. If expected neighbors are missing or remain in an incomplete state, an administrator can investigate configuration, timers, authentication, addressing, and connectivity.

Question: 105. Which IPv6 address type is designed for communication with a group of interfaces?

1. Anycast
   2. Link-local
   3. Multicast
   4. Global unicast

Correct Answer: 3. Multicast

Explanation:

An IPv6 multicast address identifies a group of interfaces, allowing a packet to be delivered to multiple interested receivers. IPv6 relies heavily on multicast because it does not use broadcast in the same way IPv4 does. Neighbor Discovery, for example, uses multicast addresses for several functions. Link-local addresses are used for communication on the local link, global unicast addresses provide routable addressing, and anycast addresses identify a group of interfaces where traffic is delivered to the nearest appropriate member.

Question: 106. What does the OSPF Full neighbor state indicate?

1. The routers have detected each other but have not exchanged databases
   2. The routers have completed synchronization of their link-state databases
   3. The routers are using BGP instead of OSPF
   4. The OSPF interface has been administratively disabled

Correct Answer: 2. The routers have completed synchronization of their link-state databases

Explanation:

The OSPF Full state indicates that the neighboring routers have successfully synchronized their link-state databases. Once the required database exchange is complete, the routers have the information necessary to calculate routes consistently within the OSPF area. On broadcast networks, not every OSPF router necessarily forms a Full adjacency with every other router because the DR and BDR reduce the number of required adjacencies. A persistent state below Full can indicate an adjacency or database synchronization problem.

Question: 107. Which Junos configuration hierarchy is used to configure a static IPv4 route?

1. protocols ospf
   2. routing-options static
   3. forwarding-options dhcp-relay
   4. interfaces lo0

Correct Answer: 2. routing-options static

Explanation:

Static routes in Junos are configured under the routing-options static hierarchy. A static route specifies a destination prefix and an appropriate next hop or other forwarding behavior. Static routing is useful for simple topologies, default routes, stub networks, and situations where an administrator wants explicit control over a route. OSPF, IS-IS, and BGP are dynamic routing protocols and are configured under their respective protocol hierarchies rather than under routing-options static.

Question: 108. Which BGP attribute is commonly used inside an autonomous system to influence the preferred outbound exit point?

1. MED
   2. AS_PATH
   3. Local Preference
   4. NEXT_HOP

Correct Answer: 3. Local Preference

Explanation:

BGP Local Preference is used within an autonomous system to influence which exit point routers should prefer for outbound traffic. A higher Local Preference value is generally preferred when comparing eligible BGP paths. Because it is propagated through iBGP, it can provide consistent outbound path-selection behavior across the autonomous system. MED serves a different purpose by providing information about preferred entry points into an autonomous system, typically from neighboring autonomous systems.

Question: 109. Which protocol does BGP use as its transport protocol?

1. UDP
   2. ICMP
   3. TCP
   4. GRE

Correct Answer: 3. TCP

Explanation:

BGP uses TCP as its transport protocol, specifically TCP port 179. TCP provides reliable, ordered delivery for BGP routing information exchanged between peers. Once a BGP session is established, routing updates and other protocol messages are exchanged through the TCP connection. This differs from protocols such as OSPF, which operates directly over IP rather than using TCP or UDP as its transport protocol.

Question: 110. What is the purpose of a BGP route reflector?

1. To eliminate the need for all iBGP routers to form a full mesh
   2. To replace OSPF area border routers
   3. To encrypt BGP updates
   4. To convert IPv4 routes into IPv6 routes

Correct Answer: 1. To eliminate the need for all iBGP routers to form a full mesh

Explanation:

A BGP route reflector reduces the requirement for a full-mesh iBGP topology. Instead of every iBGP router needing a direct session with every other iBGP router, selected routers can act as route reflectors and distribute routes to their clients. This significantly reduces the number of BGP sessions required in larger autonomous systems. Route reflection does not provide encryption or protocol translation, and it does not replace the functions performed by OSPF area border routers.

Question: 111. Which Junos command provides detailed information about a specific route, including its next hop and route preference?

1. show route <prefix> detail
   2. show system uptime
   3. show interfaces terse
   4. show chassis hardware

Correct Answer: 1. show route <prefix> detail

Explanation:

The show route <prefix> detail command provides detailed information about a specified route. Depending on the route and configuration, the output can include the route’s protocol, preference, next hop, interface, metric information, and other attributes. This makes the command particularly useful when troubleshooting why a specific route was selected or determining how traffic toward a destination will be forwarded. The other commands provide system, interface, or hardware information rather than detailed route information.

Question: 112. Which IPv4 prefix represents the RFC 1918 private address space used for many internal networks?

1. 192.0.2.0/24
   2. 172.16.0.0/12
   3. 198.51.100.0/24
   4. 203.0.113.0/24

Correct Answer: 2. 172.16.0.0/12

Explanation:

The 172.16.0.0/12 prefix is one of the three IPv4 private address ranges defined by RFC 1918. It covers addresses from 172.16.0.0 through 172.31.255.255 and is commonly used for internal networks. The other RFC 1918 ranges are 10.0.0.0/8 and 192.168.0.0/16. The prefixes 192.0.2.0/24, 198.51.100.0/24, and 203.0.113.0/24 are documentation ranges intended for examples and technical documentation.

Question: 113. What is the primary purpose of LACP on a Junos device?

1. To dynamically exchange DNS information
   2. To establish OSPF adjacencies
   3. To negotiate and maintain aggregated Ethernet links
   4. To assign IPv6 addresses automatically

Correct Answer: 3. To negotiate and maintain aggregated Ethernet links

Explanation:

LACP, or Link Aggregation Control Protocol, is used to dynamically negotiate and maintain link aggregation between compatible devices. By combining multiple physical Ethernet links into an aggregated interface, networks can increase available bandwidth and provide redundancy if an individual member link fails. LACP helps ensure that both ends agree about which physical links belong to the aggregation. It is not an IP routing protocol and does not perform IPv6 address assignment or establish OSPF adjacencies.

Question: 114. Which OSPF LSA type is normally used to advertise routes external to the OSPF autonomous system?

1. Type 1 Router LSA
   2. Type 3 Summary LSA
   3. Type 5 AS External LSA
   4. Type 2 Network LSA

Correct Answer: 3. Type 5 AS External LSA

Explanation:

OSPF Type 5 AS External LSAs are used to advertise routes that originate outside the OSPF autonomous system, such as routes redistributed from another routing protocol or static routes. Autonomous System Boundary Routers can originate these LSAs when external routes are redistributed into OSPF. Type 1 LSAs describe individual routers, Type 2 LSAs describe broadcast network segments through the DR, and Type 3 LSAs are generated by ABRs to advertise inter-area routes.

Question: 115. Which Junos command is used to verify the contents of the Layer 2 Ethernet switching table?

1. show route
   2. show ethernet-switching table
   3. show ospf database
   4. show bgp summary

Correct Answer: 2. show ethernet-switching table

Explanation:

The show ethernet-switching table command displays the Layer 2 Ethernet switching table, including learned MAC addresses and their associated interfaces or logical switching information. This command is useful when troubleshooting Layer 2 connectivity, MAC learning, VLAN behavior, or unexpected forwarding paths. The show route command examines Layer 3 routing information, while OSPF and BGP commands focus on their respective routing protocols.

Question: 116. What is the primary function of Bidirectional Forwarding Detection (BFD)?

1. To provide rapid detection of forwarding-path failures
   2. To calculate OSPF shortest paths
   3. To assign addresses through DHCP
   4. To replace BGP route advertisements

Correct Answer: 1. To provide rapid detection of forwarding-path failures

Explanation:

BFD is designed to detect forwarding-path failures quickly and can be associated with routing protocols such as OSPF, IS-IS, and BGP. It uses lightweight control packets and typically operates with much shorter detection intervals than the normal failure-detection mechanisms of many routing protocols. When BFD detects a failure, the associated routing protocol can react more quickly. BFD does not calculate routes, allocate IP addresses, or replace the routing information exchanged by routing protocols.

Question: 117. Which IPv6 prefix is reserved for link-local unicast addresses?

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

Correct Answer: 3. FE80::/10

Explanation:

The IPv6 prefix FE80::/10 is reserved for link-local unicast addresses. Link-local addresses are used for communication on the local network segment and are not intended to be routed across routers. They are commonly present on IPv6-enabled interfaces and are important for functions such as Neighbor Discovery and routing-protocol communication. FC00::/7 is associated with unique local addresses, FF00::/8 is used for multicast, and 2000::/3 covers a major portion of the global unicast address space.

Question: 118. Which Junos command displays the system’s current uptime and basic system-time information?

1. show system uptime
   2. show system alarms
   3. show chassis hardware
   4. show configuration

Correct Answer: 1. show system uptime

Explanation:

The show system uptime command provides information about how long the Junos device has been running, along with related system-time and uptime information. This can be useful when troubleshooting unexpected reboots, verifying recent system restarts, or checking how long a device has remained operational. show system alarms is used to examine active system alarms, while show chassis hardware displays hardware inventory and show configuration displays configuration information.

Question: 119. What is the main purpose of the OSPF Designated Router (DR) on a broadcast network?

1. To provide DHCP services to all OSPF routers
   2. To reduce the number of OSPF adjacencies and optimize LSA flooding
   3. To replace the OSPF shortest-path algorithm
   4. To provide Internet connectivity for the OSPF area

Correct Answer: 2. To reduce the number of OSPF adjacencies and optimize LSA flooding

Explanation:

On broadcast networks such as Ethernet, OSPF elects a Designated Router to reduce the number of full adjacencies required and to make link-state information exchange more efficient. Without a DR, the number of potential router-to-router adjacencies can grow significantly as more routers are added to the segment. The DR participates in the exchange and flooding of LSAs for the multi-access network. A Backup Designated Router is also elected so that OSPF can continue efficiently if the DR becomes unavailable.

Question: 120. When forwarding an IPv4 packet, which routing-table rule determines which matching route is normally selected?

1. Highest route metric regardless of prefix length
   2. First route displayed in the configuration
   3. Longest-prefix match
   4. Route with the largest next-hop address

Correct Answer: 3. Longest-prefix match

Explanation:

Routers normally use longest-prefix matching when selecting a route for an IPv4 destination. This means that when multiple routes match the destination address, the route with the most specific prefix is preferred. For example, a /24 route is more specific than a /16 route and therefore can be selected for destinations within that /24 network. Route preference and other selection mechanisms can determine which route is installed when competing routes represent the same destination prefix, but forwarding decisions first rely on the most specific matching route.