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

Question: 241. Which Junos command displays the forwarding table used to make packet-forwarding decisions?

1. show route forwarding-table
   2. show configuration
   3. show ospf neighbor
   4. show system uptime

Correct Answer: 1. show route forwarding-table

Explanation:

The show route forwarding-table command displays the forwarding table used by the device to make packet-forwarding decisions. The forwarding table is derived from routing information but is specifically concerned with how packets are forwarded toward their destinations. show configuration displays configuration data, show ospf neighbor displays OSPF neighbor relationships, and show system uptime reports system uptime. When troubleshooting forwarding behavior, examining the forwarding table can help determine whether the expected next hop and outgoing interface have been installed.

Question: 242. Which BGP attribute is commonly used to influence the preferred inbound path into an autonomous system?

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

Correct Answer: 2. MED

Explanation:

The Multi-Exit Discriminator (MED) is commonly used to provide a neighboring autonomous system with information about which entry point should be preferred when multiple connections exist between the two autonomous systems. Lower MED values are generally preferred when the attribute is compared. Local Preference is normally used inside an autonomous system to influence outbound traffic, while NEXT_HOP identifies the next-hop address and Origin indicates how the route entered BGP. MED therefore provides a mechanism for influencing the neighboring AS’s choice of inbound path.

Question: 243. Which OSPF area is normally used as the backbone for inter-area routing?

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

Correct Answer: 3. Area 0

Explanation:

OSPF Area 0, also called the backbone area, is the central area through which inter-area OSPF routing is normally organized. Area Border Routers connect other OSPF areas to the backbone and exchange summarized routing information between areas. A properly designed OSPF topology generally maintains connectivity between non-backbone areas and Area 0. Other area numbers can be used for regular OSPF areas, but Area 0 has a special architectural role. Understanding the backbone concept is important when troubleshooting inter-area route propagation.

Question: 244. Which Junos command displays detailed information about a particular routing-table prefix?

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

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 protocol, the output can include the route’s protocol source, preference, next hop, interface, and other relevant attributes. This makes it particularly useful when troubleshooting why a route was selected or how traffic will be forwarded. The other commands serve different purposes: interface status, hardware inventory, and system alarm reporting. Focusing on one prefix is often more effective than reviewing the entire routing table during detailed route troubleshooting.

Question: 245. Which protocol uses a hop-count metric and has a maximum usable hop count of 15?

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

Correct Answer: 4. RIP

Explanation:

Routing Information Protocol (RIP) uses hop count as its routing metric. A route with a hop count of 15 is considered reachable, while a hop count of 16 represents an unreachable destination in traditional RIP. This limitation makes RIP unsuitable for many large or complex networks. OSPF uses a cost metric, IS-IS uses link-state metrics, and BGP uses path attributes rather than a simple hop-count metric. RIP’s simplicity is useful for understanding distance-vector routing, although its scalability is limited compared with modern routing protocols.

Question: 246. Which OSPF LSA is originated by a Designated Router to represent a multiaccess network?

1. Type 5
   2. Type 2
   3. Type 3
   4. Type 1

Correct Answer: 2. Type 2

Explanation:

An OSPF Type 2 Network LSA is originated by the Designated Router on applicable multiaccess networks. It represents the shared network segment and identifies the routers attached to that network. This allows OSPF’s link-state database to represent the multiaccess segment efficiently rather than requiring every router to describe every individual adjacency in the same manner. Type 1 Router LSAs describe individual routers, Type 3 Summary LSAs advertise inter-area networks, and Type 5 LSAs describe external routes. The Type 2 LSA is therefore closely associated with the DR function.

Question: 247. Which BGP attribute helps prevent routing loops between autonomous systems?

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

Correct Answer: 3. AS_PATH

Explanation:

The BGP AS_PATH attribute helps prevent routing loops by recording 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 because accepting it could create a routing loop. AS_PATH also contributes to BGP path selection, where a shorter path is generally preferred when earlier selection criteria do not determine a route. MED, Local Preference, and NEXT_HOP perform different functions and do not provide this same fundamental AS-level loop-prevention mechanism.

Question: 248. Which Junos command can be used to verify the device’s current uptime?

1. show system uptime
   2. show system alarms
   3. show route
   4. show bgp summary

Correct Answer: 1. show system uptime

Explanation:

The show system uptime command displays information about how long the Junos device has been running, along with related system uptime information. This is useful when investigating recent reboots, unexpected system restarts, or determining how long the current operating environment has been active. show system alarms is used for alarm information, show route displays routing information, and show bgp summary focuses on BGP peers and routing statistics. Uptime information can provide useful context during system troubleshooting and maintenance.

Question: 249. What is the primary purpose of a BGP route reflector?

1. To replace OSPF Area 0
   2. To eliminate the need for all iBGP peers to form a full mesh
   3. To provide first-hop gateway redundancy
   4. To aggregate physical Ethernet links

Correct Answer: 2. To eliminate the need for all iBGP peers to form a full mesh

Explanation:

A BGP route reflector reduces the need for a full-mesh iBGP design. Without route reflection, iBGP speakers traditionally need direct sessions with other iBGP speakers to distribute routes throughout the autonomous system. A route reflector can receive routes from clients and reflect appropriate routes to other clients and peers. This simplifies BGP configuration and improves scalability in larger networks. Route reflectors do not replace OSPF’s backbone, provide gateway redundancy like VRRP, or aggregate Ethernet links like LACP.

Question: 250. Which IPv6 prefix identifies unique local unicast addresses?

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

Correct Answer: 3. FC00::/7

Explanation:

The FC00::/7 prefix is reserved for IPv6 Unique Local Addresses (ULAs). These addresses are intended for internal network use and are not designed for global Internet routing. They are conceptually similar to private IPv4 addressing, although their addressing model is different. FE80::/10 is used for link-local addresses, FF00::/8 is the IPv6 multicast range, and 2000::/3 is commonly associated with globally routable unicast addresses. Recognizing these IPv6 address ranges is important when troubleshooting addressing and route propagation.

Question: 251. Which OSPF state indicates that a router has completed database synchronization with its neighbor?

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

Correct Answer: 3. Full

Explanation:

The OSPF Full state indicates that neighboring routers have completed the required link-state database synchronization. Once routers reach Full, they have exchanged the necessary LSAs and maintain synchronized databases for the applicable adjacency. The Exchange state involves exchanging Database Description information, while Loading involves requesting and receiving additional LSAs. Init occurs earlier, when a router has received a Hello but has not yet established two-way communication. A Full state is therefore an important indicator that an OSPF adjacency has successfully completed synchronization.

Question: 252. Which Junos feature allows multiple physical Ethernet interfaces to operate as one logical interface?

1. VRRP
   2. LACP
   3. Aggregated Ethernet
   4. BFD

Correct Answer: 3. Aggregated Ethernet

Explanation:

Aggregated Ethernet allows multiple physical Ethernet interfaces to function together as a single logical interface. This can provide increased bandwidth and link redundancy. LACP can be used to dynamically negotiate and manage membership in an aggregated Ethernet bundle, but the logical interface itself is the aggregated Ethernet interface. VRRP provides gateway redundancy, while BFD provides rapid failure detection. On Junos devices, aggregated Ethernet is therefore an important mechanism for combining physical links into a single logical connection.

Question: 253. Which routing protocol uses TCP as its transport protocol?

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

Correct Answer: 2. BGP

Explanation:

BGP uses TCP as its transport protocol, with TCP port 179 assigned for BGP sessions. TCP provides reliable, ordered delivery of BGP protocol messages between peers. OSPF operates directly over IP using its own protocol number rather than TCP or UDP. IS-IS operates at the data-link layer, and traditional RIP uses UDP. When troubleshooting BGP session establishment, verifying IP reachability and TCP connectivity to port 179 can therefore be important.

Question: 254. Which Junos command displays the current configuration hierarchy?

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

Correct Answer: 2. show configuration

Explanation:

The show configuration command displays the current Junos configuration hierarchy. It is commonly used to review configured interfaces, routing protocols, policies, system settings, and other configuration elements. This command is especially useful when verifying how a device is configured before making changes. show route displays routing information, show interfaces terse summarizes interface status, and show system uptime reports system runtime information. Understanding the distinction between configuration and operational commands is essential when troubleshooting Junos devices.

Question: 255. Which BGP community is used to prevent a route from being exported outside the local autonomous system?

1. no-export
   2. no-advertise
   3. internet
   4. accept-own

Correct Answer: 1. no-export

Explanation:

The BGP no-export community is used to prevent a route from being advertised outside the local autonomous system through normal eBGP propagation. The route can still be distributed internally according to the autonomous system’s BGP configuration. The no-advertise community is more restrictive because it prevents the route from being advertised to any BGP peer. The internet community represents normal advertisement behavior. These communities are useful for implementing route-control policies and limiting the scope of route propagation.

Question: 256. Which protocol provides rapid detection of failures between directly connected routing devices?

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

Correct Answer: 2. BFD

Explanation:

Bidirectional Forwarding Detection (BFD) provides rapid detection of forwarding-path failures between network devices. It is designed to operate with very short detection intervals and can work with routing protocols such as OSPF and BGP. Once a failure is detected, the associated routing protocol can react rather than waiting for its normal, potentially longer, timeout. VRRP provides gateway redundancy, LACP manages link aggregation, and DHCP provides address configuration services. BFD is therefore specifically suited to fast failure detection.

Question: 257. Which IPv6 address is the loopback address?

1. FE80::1
   2. FC00::1
   3. ::1
   4. FF02::1

Correct Answer: 3. ::1

Explanation:

The IPv6 loopback address is ::1. It is used by an IPv6 host to refer to itself, similar to the IPv4 loopback address 127.0.0.1. Traffic sent to the IPv6 loopback address does not leave the local device. FE80::/10 represents link-local addresses, FC00::/7 represents unique local addresses, and FF02::1 is an IPv6 multicast address. The loopback address is commonly used for local testing and validating IPv6 protocol-stack operation.

Question: 258. Which BGP attribute describes how a route was introduced into BGP?

1. Origin
   2. AS_PATH
   3. NEXT_HOP
   4. MED

Correct Answer: 1. Origin

Explanation:

The BGP Origin attribute indicates how the route was introduced into BGP. Common Origin values represent routes learned through an interior gateway protocol, explicitly originated into BGP, or obtained through incomplete redistribution or other mechanisms. Origin participates in BGP path selection after several higher-priority criteria. AS_PATH identifies autonomous systems traversed, NEXT_HOP identifies the next-hop address, and MED can influence the preferred entry point between autonomous systems. Understanding the Origin attribute helps explain why BGP may prefer one otherwise comparable path over another.

Question: 259. Which Junos command can be used to verify active OSPF neighbors?

1. show ospf neighbor
   2. show bgp summary
   3. show route forwarding-table
   4. show chassis hardware

Correct Answer: 1. show ospf neighbor

Explanation:

The show ospf neighbor command displays information about OSPF neighbor relationships, including neighbor identifiers, interface information, adjacency states, and other operational details. It is a fundamental troubleshooting command when determining whether OSPF adjacencies have formed correctly. show bgp summary focuses on BGP sessions, show route forwarding-table displays forwarding information, and show chassis hardware displays hardware inventory. If an expected OSPF route is missing, verifying the neighbor state is often an important first step.

Question: 260. What is the primary function of an OSPF Backup Designated Router?

1. To replace all OSPF areas
   2. To act as a standby for the Designated Router
   3. To provide BGP route reflection
   4. To assign IPv4 addresses to hosts

Correct Answer: 2. To act as a standby for the Designated Router

Explanation:

The OSPF Backup Designated Router (BDR) serves as a standby for the Designated Router on applicable multiaccess networks. If the active DR fails, the BDR can take over the DR role, helping maintain stable OSPF operations and reducing the disruption caused by a DR failure. The BDR participates in the OSPF adjacency process and receives relevant routing information while serving as the backup. It does not replace OSPF areas, perform BGP route reflection, or provide host address assignment. Its primary purpose is DR redundancy.