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

Question: 301. Which Junos command displays the routing table entries learned through OSPF?

1. show route protocol ospf
   2. show ospf interface
   3. show route protocol bgp
   4. show ospf database

Correct Answer: 1. show route protocol ospf

Explanation:

The show route protocol ospf command filters the Junos routing table to display routes whose protocol source is OSPF. This is useful when troubleshooting whether OSPF-learned routes have been installed in the routing table. show ospf interface provides interface-related OSPF information, while show ospf database displays the OSPF link-state database rather than only installed routes. show route protocol bgp specifically filters for BGP routes.

Question: 302. In BGP, which attribute is normally used to select the preferred exit point from an autonomous system?

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

Correct Answer: 2. Local Preference

Explanation:

BGP Local Preference is used within an autonomous system to influence which exit point is preferred for outbound traffic. A higher Local Preference value is generally preferred. It is an internal BGP attribute and is commonly applied through routing policy. MED serves a different purpose by providing information about preferred entry points into an autonomous system from a neighboring AS. The NEXT_HOP attribute identifies the next-hop address for reaching a route, while Origin indicates how the route entered BGP.

Question: 303. Which OSPF packet type is used to establish and maintain neighbor relationships?

1. Link-State Update
   2. Database Description
   3. Link-State Request
   4. Hello

Correct Answer: 4. Hello

Explanation:

OSPF Hello packets are used to discover neighboring OSPF routers and maintain neighbor relationships. They are sent periodically through OSPF-enabled interfaces and contain information such as the router ID, area, timers, and neighbor information. Compatible Hello parameters are required before routers can form an adjacency. Database Description packets synchronize database summaries, Link-State Requests request specific LSAs, and Link-State Updates carry LSAs. Therefore, Hello is the OSPF packet type associated directly with neighbor discovery and relationship maintenance.

Question: 304. What IPv4 prefix represents the default route?

1. 255.255.255.255/32
   2. 127.0.0.0/8
   3. 0.0.0.0/0
   4. 224.0.0.0/4

Correct Answer: 3. 0.0.0.0/0

Explanation:

The IPv4 default route is represented by 0.0.0.0/0. It matches any IPv4 destination for which a more specific route is not present in the routing table. The /0 prefix length means that no destination bits are required to match, making it the least-specific IPv4 route. 255.255.255.255/32 is the limited broadcast address, 127.0.0.0/8 is reserved for loopback addressing, and 224.0.0.0/4 is the IPv4 multicast address range.

Question: 305. What is the primary purpose of Graceful Routing Engine Switchover (GRES) in Junos?

1. To redistribute OSPF routes between areas
   2. To provide uninterrupted packet forwarding during a Routing Engine switchover
   3. To encrypt routing protocol sessions
   4. To replace BFD for failure detection

Correct Answer: 2. To provide uninterrupted packet forwarding during a Routing Engine switchover

Explanation:

GRES is a Junos high-availability feature designed to help maintain packet forwarding when the active Routing Engine switches to the backup Routing Engine. The Packet Forwarding Engine can continue forwarding traffic while control-plane responsibilities transition. GRES itself does not provide routing-protocol state synchronization; features such as Nonstop Active Routing address preservation of protocol state. GRES also does not encrypt routing sessions or replace BFD. Its primary role is to minimize forwarding disruption during a Routing Engine switchover.

Question: 306. Which OSPF LSA type describes the links and networks directly connected to an OSPF router within an area?

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

Correct Answer: 4. Type 1 Router LSA

Explanation:

A Type 1 Router LSA is originated by each OSPF router to describe its active links, interfaces, and directly connected networks within an area. Every OSPF router maintains Router LSAs as part of the link-state database used by the SPF calculation. A Type 2 Network LSA is generated by the designated router on broadcast or similar multiaccess networks, Type 3 Summary LSAs are originated by ABRs to advertise networks between areas, and Type 5 LSAs describe external routes redistributed into OSPF.

Question: 307. Which BGP attribute can be used by one autonomous system to communicate a preference for how another AS should enter its network?

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

Correct Answer: 1. MED

Explanation:

The Multi-Exit Discriminator (MED) is a BGP attribute that can be used to influence which entry point a neighboring autonomous system should prefer when multiple links exist between the autonomous systems. Lower MED values are generally preferred when comparing otherwise eligible paths from the same neighboring AS. Local Preference is primarily used within an AS to influence outbound path selection. AS_PATH records autonomous systems traversed by a route, while NEXT_HOP identifies the next-hop address used to reach the destination.

Question: 308. Which Junos command provides detailed information about a specific route, including protocol and next-hop information?

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

Correct Answer: 3. show route <prefix> detail

Explanation:

The show route <prefix> detail command displays detailed information about a particular routing-table entry. Depending on the route, the output can include the protocol that learned the route, route preference, next hop, interface information, and other attributes. This makes it especially useful for troubleshooting why a route was selected or how traffic will be forwarded. show route terse provides a more compact routing-table view, while show interfaces terse and show system uptime provide information about interfaces and system uptime respectively.

Question: 309. Which routing protocol is commonly used as an interior gateway protocol and is based on link-state technology?

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

Correct Answer: 2. OSPF

Explanation:

OSPF, or Open Shortest Path First, is a link-state interior gateway protocol used to exchange routing information within an autonomous system. Routers build a link-state database and use the Shortest Path First algorithm to calculate routes. RIP is a distance-vector protocol, while BGP is primarily used as an exterior gateway protocol for inter-AS routing. ARP is not a routing protocol; it resolves IPv4 addresses to Layer 2 MAC addresses on local networks. OSPF therefore fits both the interior-routing and link-state requirements.

Question: 310. Which Junos command displays the current committed configuration in configuration mode?

1. show configuration
   2. show route
   3. show interfaces terse
   4. show system alarms

Correct Answer: 1. show configuration

Explanation:

In Junos configuration mode, show configuration displays the current configuration hierarchy. It is commonly used to review configured statements before making additional changes. This differs from operational-mode commands such as show route, which displays routing information, and show system alarms, which reports system alarms. The command show configuration is therefore an important basic tool for inspecting the device configuration while working in configuration mode.

Question: 311. Which BGP community prevents a route from being advertised to any BGP peer?

1. no-export
   2. internet
   3. no-advertise
   4. local-AS

Correct Answer: 3. no-advertise

Explanation:

The BGP no-advertise community indicates that a route should not be advertised to any BGP peer. This provides a mechanism for controlling the propagation of selected routes through BGP policy. The no-export community has a different scope: it prevents a route from being advertised outside the local autonomous system or confederation context. The internet community indicates that the route may be advertised to the Internet, subject to policy. Understanding these community behaviors is important when controlling BGP route propagation.

Question: 312. Which IPv6 address range is reserved for link-local unicast addresses?

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

Correct Answer: 2. FE80::/10

Explanation:

IPv6 link-local unicast addresses use the FE80::/10 prefix. These addresses are automatically associated with IPv6-enabled interfaces and are intended for communication on the local link. They are not routable beyond the local Layer 2 network. FC00::/7 is used for unique local addresses, FF00::/8 identifies multicast addresses, and 2000::/3 represents the commonly used global unicast range. Link-local addresses are particularly important for IPv6 neighbor discovery and routing-protocol operation.

Question: 313. Which Junos command displays OSPF neighbor relationships and their current states?

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

Correct Answer: 1. show ospf neighbor

Explanation:

The show ospf neighbor command displays OSPF neighbor information, including neighbor router IDs, interface relationships, adjacency states, and related details. It is a key troubleshooting command when verifying whether OSPF adjacencies have formed correctly. show ospf database focuses on LSAs stored in the OSPF link-state database, while show route protocol ospf displays routes learned through OSPF. show bgp summary is used for BGP neighbor and session information rather than OSPF.

Question: 314. What does the BGP NEXT_HOP attribute identify?

1. The autonomous system path used by the route
   2. The address of the next router to which traffic should be forwarded
   3. The BGP route’s origin type
   4. The local preference assigned to the route

Correct Answer: 2. The address of the next router to which traffic should be forwarded

Explanation:

The BGP NEXT_HOP attribute identifies the IP address that should be used as the next hop toward the advertised destination. The receiving router uses this information, together with its routing and forwarding tables, to determine how traffic should reach the destination network. AS_PATH identifies the autonomous systems traversed, Origin describes how the route entered BGP, and Local Preference influences outbound path selection within an autonomous system. Correct NEXT_HOP handling is therefore essential for BGP routes to be usable.

Question: 315. Which IPv4 address range is designated for private addressing in the RFC 1918 192.168/16 block?

1. 172.0.0.0/8
   2. 192.168.0.0/16
   3. 169.254.0.0/16
   4. 224.0.0.0/4

Correct Answer: 2. 192.168.0.0/16

Explanation:

The 192.168.0.0/16 range is one of the RFC 1918 private IPv4 address blocks. It contains addresses from 192.168.0.0 through 192.168.255.255 and is commonly used inside private networks. Other RFC 1918 blocks include 10.0.0.0/8 and 172.16.0.0/12. The 169.254.0.0/16 range is used for IPv4 link-local addressing, while 224.0.0.0/4 is reserved for IPv4 multicast. Private addresses are not globally routable on the public Internet.

Question: 316. In which OSPF neighbor state are routers considered fully adjacent and have synchronized their link-state databases?

1. Init
   2. 2-Way
   3. Full
   4. Exchange

Correct Answer: 3. Full

Explanation:

The OSPF Full state indicates that two routers have completed database synchronization and are fully adjacent. At this stage, the routers have exchanged the necessary link-state information and their databases are synchronized for the adjacency. The 2-Way state indicates bidirectional communication but does not necessarily mean a full adjacency exists. Exchange involves the process of exchanging database information, while Init indicates that a router has received a Hello from a neighbor but has not yet established bidirectional communication.

Question: 317. Which Junos command is used to view active system alarms?

1. show system alarms
   2. show chassis hardware
   3. show system uptime
   4. show log messages

Correct Answer: 1. show system alarms

Explanation:

The show system alarms command displays active system alarms reported by the Junos device. It can be useful when checking for hardware, environmental, or other system-level conditions that require attention. show chassis hardware provides hardware inventory information, while show system uptime reports system uptime and related information. Logs can provide additional diagnostic details, but show system alarms is the direct command for checking currently reported system alarms.

Question: 318. Which technology allows multiple Ethernet links to operate as one logical aggregated interface?

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

Correct Answer: 3. LACP

Explanation:

LACP, the Link Aggregation Control Protocol, is used to dynamically negotiate and maintain link aggregation between compatible devices. Multiple physical Ethernet interfaces can be combined into a logical aggregated Ethernet interface, increasing available bandwidth and providing link-level redundancy. LACP helps ensure that both sides agree on which links participate in the aggregation. VRRP provides first-hop gateway redundancy, BFD provides rapid failure detection, and GRES supports Routing Engine switchover. These technologies address different networking requirements.

Question: 319. Which BGP attribute helps prevent routing loops between autonomous systems?

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

Correct Answer: 3. AS_PATH

Explanation:

The BGP AS_PATH attribute records the autonomous systems through which a route advertisement has passed. When a BGP router receives an advertisement containing its own autonomous system number in the AS_PATH, it can reject the route as a potential routing loop. This mechanism is fundamental to inter-AS BGP operation. Local Preference influences outbound path selection within an AS, MED can influence inbound path selection by a neighboring AS, and Origin indicates how the route was introduced into BGP. AS_PATH is therefore central to BGP loop prevention.

Question: 320. Which Junos command provides a summary of BGP peer sessions and their status?

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

Correct Answer: 1. show bgp summary

Explanation:

The show bgp summary command provides a concise overview of BGP sessions, including peer information, autonomous system details, message statistics, and the current session state. It is commonly used as a first diagnostic command when checking whether BGP peers are established. show route protocol bgp focuses on routes learned through BGP rather than peer-session status. show bgp neighbor provides more detailed information about a particular BGP neighbor, while show ospf neighbor is specific to OSPF.