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

Question: 201. Which Junos command displays the routing table entries learned through OSPF?

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

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 successfully entered the routing table. show ospf database instead displays the OSPF link-state database, while show route protocol bgp filters for BGP routes. show interfaces terse provides interface status and addressing information rather than routing information. Filtering the routing table by protocol is particularly useful when verifying route installation after establishing OSPF neighbor relationships.

Question: 202. In BGP, which attribute is commonly used within an autonomous system to select the preferred outbound exit point?

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

Correct Answer: 3. Local Preference

Explanation:

BGP Local Preference is used within an autonomous system to influence which exit point should be preferred for outbound traffic. A higher Local Preference value is preferred. Because the attribute is propagated through iBGP, it can influence routing decisions across the autonomous system. MED, by contrast, is primarily used to provide information about preferred entry points into an AS from neighboring networks. AS_PATH records autonomous systems traversed and also participates in path selection and loop prevention. The Origin attribute identifies how a route entered BGP and has a lower role in this particular decision.

Question: 203. Which OSPF packet type is used to request specific link-state information from a neighbor?

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

Correct Answer: 3. Link-State Request

Explanation:

An OSPF Link-State Request, or LSR, is used by a router to request specific link-state advertisements from an OSPF neighbor. During database synchronization, routers use Database Description packets to exchange summaries of their LSDB contents. If a router determines that it needs more detailed information, it sends an LSR. The neighbor responds with a Link-State Update containing the requested LSAs. Link-State Acknowledgment packets are used to acknowledge receipt of LSAs. These packet types work together to maintain synchronized OSPF link-state databases.

Question: 204. What is the primary purpose of BFD on a Junos device?

1. To assign IPv6 addresses automatically
   2. To provide rapid detection of forwarding-path failures
   3. To select the BGP origin attribute
   4. To create an OSPF area hierarchy

Correct Answer: 2. To provide rapid detection of forwarding-path failures

Explanation:

Bidirectional Forwarding Detection (BFD) provides rapid detection of failures in forwarding paths between network devices. It operates independently of many routing protocols and can notify a protocol such as OSPF or BGP when a forwarding path becomes unavailable. This allows routing protocols to react much faster than they might using their normal protocol timers. BFD does not assign IPv6 addresses, determine BGP Origin values, or create OSPF areas. On Junos devices, BFD is particularly useful where fast failure detection is required for routing adjacencies.

Question: 205. Which IPv6 prefix is reserved for link-local unicast addresses?

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

Correct Answer: 4. FE80::/10

Explanation:

The IPv6 prefix FE80::/10 is reserved for link-local unicast addresses. Link-local addresses are automatically associated with IPv6-enabled interfaces and are valid only on the local Layer 2 link. They are commonly used for neighbor discovery and routing protocol communication. FC00::/7 is reserved for unique local addresses, while FF00::/8 represents IPv6 multicast addresses. The 2000::/3 range is associated with globally routable unicast IPv6 addresses. Link-local addressing is therefore an essential part of normal IPv6 operation.

Question: 206. Which BGP attribute contains the sequence of autonomous systems through which a route has passed?

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

Correct Answer: 2. AS_PATH

Explanation:

The BGP AS_PATH attribute records the autonomous systems that a route advertisement has traversed. It serves two important purposes: it provides information used in BGP path selection, and it helps prevent routing loops. When an eBGP router advertises a route to another autonomous system, it normally adds its own AS number to the AS_PATH. If a router receives a route containing its own AS number, it can reject the route as a potential loop. Local Preference influences outbound path selection, MED can influence inbound path selection, and NEXT_HOP identifies the next-hop address.

Question: 207. Which Junos command provides a concise summary of interface administrative and operational status?

1. show interfaces terse
   2. show route
   3. show system alarms
   4. show chassis hardware

Correct Answer: 1. show interfaces terse

Explanation:

The show interfaces terse command provides a compact overview of interfaces, including their administrative and operational status and configured addressing information. It is particularly useful when quickly checking whether interfaces are up or down without displaying the extensive details produced by show interfaces. show route displays routing information, show system alarms reports system alarms, and show chassis hardware displays hardware inventory. Network administrators commonly use the terse interface command as an initial troubleshooting step before examining detailed interface statistics.

Question: 208. Which OSPF neighbor state indicates that the routers have fully synchronized their link-state databases?

1. Init
   2. Exchange
   3. Full
   4. Attempt

Correct Answer: 3. Full

Explanation:

The OSPF Full state indicates that neighboring routers have completed database synchronization. In this state, the routers have exchanged the necessary link-state information and have synchronized their link-state databases. Other OSPF states occur earlier in the neighbor formation process. Init indicates that a Hello has been received but two-way communication has not yet been established, while Exchange involves database description exchange. Attempt is associated with specific nonbroadcast network behavior. A stable Full adjacency is therefore an important indication that OSPF neighbors have successfully synchronized their routing information.

Question: 209. Which BGP community prevents a route from being advertised outside the local autonomous system?

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

Correct Answer: 2. no-export

Explanation:

The BGP no-export community instructs BGP speakers not to advertise a route to an eBGP peer outside the local autonomous system. The route can still be distributed within the autonomous system through appropriate iBGP behavior. The no-advertise community is more restrictive because it prevents the route from being advertised to any BGP peer. The internet community has the opposite general meaning and allows normal advertisement. Understanding BGP communities is important when controlling how routes propagate between autonomous systems and preventing unintended external route advertisements.

Question: 210. Which routing protocol uses TCP port 179 for its transport connection?

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

Correct Answer: 4. BGP

Explanation:

BGP uses TCP port 179 to establish its reliable transport connection between BGP peers. TCP provides reliable, ordered delivery for BGP messages, which include OPEN, UPDATE, KEEPALIVE, and NOTIFICATION messages. OSPF does not use TCP or UDP because it operates directly over IP using its own protocol number. RIP uses UDP, traditionally on port 520 for IPv4, while IS-IS operates directly at the data-link layer rather than using TCP. Knowing BGP’s TCP transport behavior is fundamental when troubleshooting peer establishment and connectivity.

Question: 211. What does the Junos commit check command do?

1. Activates the configuration and reboots the device
   2. Validates the candidate configuration without activating it
   3. Deletes the candidate configuration
   4. Displays the forwarding table

Correct Answer: 2. Validates the candidate configuration without activating it

Explanation:

The Junos commit check command validates the candidate configuration for syntax and configuration consistency without actually activating the changes. It is useful before a real commit because it can identify configuration problems while leaving the active configuration unchanged. A normal commit is required to activate a valid candidate configuration. Commands such as show route or forwarding-table commands provide routing information and are unrelated to candidate configuration validation. Administrators can therefore use commit check as a safe verification step before making configuration changes active.

Question: 212. Which OSPF LSA type is originated by an Area Border Router to describe networks in another area?

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

Correct Answer: 1. Type 3 Summary LSA

Explanation:

An OSPF Type 3 Summary LSA is generated by an Area Border Router (ABR) to advertise network information from one OSPF area into another. This allows routers in different areas to learn about reachable networks without requiring every area to share the same detailed link-state database. Type 1 Router LSAs describe individual routers within an area, while Type 2 Network LSAs describe broadcast or NBMA network segments represented by a designated router. Type 5 LSAs describe external routes redistributed into OSPF. Type 3 LSAs are therefore central to inter-area routing.

Question: 213. What is the purpose of an OSPF Designated Router on a broadcast network?

1. To replace the routing table
   2. To assign IP addresses to hosts
   3. To reduce the number of full OSPF adjacencies and manage LSA flooding
   4. To provide BGP route reflection

Correct Answer: 3. To reduce the number of full OSPF adjacencies and manage LSA flooding

Explanation:

On a broadcast multiaccess network, OSPF elects a Designated Router (DR) to reduce the number of full neighbor adjacencies and organize link-state advertisement flooding. 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. The DR provides a central point for exchanging routing information on the multiaccess network. A Backup Designated Router (BDR) is also elected to provide continuity if the DR fails. DR functionality is specific to OSPF operation on applicable multiaccess networks.

Question: 214. Which Junos routing table is primarily used for IPv6 unicast routes?

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

Correct Answer: 2. inet6.0

Explanation:

The Junos inet6.0 routing table is the primary routing table for IPv6 unicast routes. In contrast, inet.0 is primarily used for IPv4 unicast routing. Other routing tables support different protocol families or forwarding functions. When troubleshooting IPv6 route installation, administrators can use commands such as show route table inet6.0 to inspect the IPv6 unicast routing table. Understanding Junos routing-table naming is important because a route can be correctly learned by a routing protocol but still be difficult to locate if the administrator examines the wrong protocol-family table.

Question: 215. Which BGP attribute is generally preferred when its value is lower during standard BGP path selection?

1. Local Preference
   2. MED
   3. Weight
   4. AS_PATH length

Correct Answer: 4. AS_PATH length

Explanation:

AS_PATH length is generally preferred when it is shorter, assuming earlier BGP path-selection criteria have not already selected another route. A shorter AS_PATH typically represents fewer autonomous-system hops to the destination. Local Preference is generally preferred when higher, not lower. MED is generally preferred when lower, but its comparison behavior depends on configuration and circumstances. Vendor-specific attributes such as Weight can also influence selection where supported. The important distinction is that AS_PATH contributes to BGP path selection by allowing the router to compare the number of autonomous systems represented in candidate paths.

Question: 216. Which protocol provides first-hop gateway redundancy by allowing multiple routers to share a virtual IP address?

1. VRRP
   2. LACP
   3. BFD
   4. IS-IS

Correct Answer: 1. VRRP

Explanation:

VRRP, or Virtual Router Redundancy Protocol, provides first-hop redundancy by allowing multiple routers to participate in a virtual router configuration. Hosts can use a shared virtual IP address as their default gateway. One router operates as the active master for forwarding, while another router can take over if the active router becomes unavailable. LACP is used for link aggregation, BFD provides rapid failure detection, and IS-IS is a link-state routing protocol. VRRP therefore addresses gateway availability rather than link aggregation or dynamic route calculation.

Question: 217. Which Junos command displays the current candidate configuration differences compared with the active configuration?

1. show configuration
   2. show | compare
   3. show route
   4. show system uptime

Correct Answer: 2. show | compare

Explanation:

The Junos show | compare command is used to display differences between the candidate configuration and the currently active configuration. It is especially useful after making configuration changes and before committing them, because it lets the administrator review exactly what will be changed. show configuration displays configuration information but does not specifically provide the same comparison view. show route examines routing information, while show system uptime reports system uptime. Reviewing configuration differences before committing helps reduce accidental or unintended changes.

Question: 218. Which IPv6 address range is used for multicast addresses?

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

Correct Answer: 3. FF00::/8

Explanation:

IPv6 multicast addresses use the FF00::/8 prefix. Multicast allows packets to be delivered to a group of interested receivers rather than to a single destination or every host on a network. IPv6 uses multicast extensively for functions such as Neighbor Discovery and various routing protocol operations. FE80::/10 is reserved for link-local unicast addresses, FC00::/7 is used for unique local addresses, and 2000::/3 is associated with globally routable unicast addressing. Recognizing the FF00::/8 prefix is therefore important when identifying IPv6 multicast traffic.

Question: 219. Which BGP attribute is primarily used to influence how traffic enters an autonomous system from a neighboring AS?

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

Correct Answer: 2. MED

Explanation:

The BGP Multi-Exit Discriminator (MED) can be used to influence which entry point a neighboring autonomous system prefers when multiple links are available between the same autonomous systems. A lower MED is generally preferred when comparing applicable paths. Local Preference is instead commonly used inside an autonomous system to influence the preferred outbound exit point. NEXT_HOP identifies the next-hop address, while Origin indicates how the route entered BGP. MED is therefore particularly relevant when an organization wants to provide a neighboring AS with information about preferred inbound paths.

Question: 220. Which Junos command displays detailed information about a specific route, including its protocol and next-hop information?

1. show interfaces
   2. show route protocol ospf
   3. show route <prefix> detail
   4. show chassis hardware

Correct Answer: 3. show route <prefix> detail

Explanation:

The show route <prefix> detail command provides detailed information about a specific routing-table entry. Depending on the route, the output can include its protocol source, preference, next-hop information, interface information, and other attributes useful for troubleshooting. show route protocol ospf filters routes based on their protocol source but is not focused on a single prefix. show interfaces provides interface information, while show chassis hardware reports hardware inventory. Examining an individual route in detail is particularly useful when investigating why Junos selected a particular path.