View Full Juniper JN0-336 Exam Dumps and Practice Test Dumps

 

Question 361.

Which BGP feature reduces the number of internal peer sessions?

1. Route reflector
2. MED processing
3. Community tagging
4. Origin selection

Correct Answer: 1

Explanation:

A BGP route reflector reduces the need for a full mesh of internal BGP sessions. Instead of requiring every internal BGP router to establish a direct session with every other internal peer, selected clients can exchange routes through a route reflector. The reflector receives routes and redistributes them according to its configured behavior. This design can significantly simplify large internal BGP topologies. MED, communities, and origin attributes influence route processing but do not provide the scalability mechanism associated with route reflectors. Proper reflector design also requires consideration of redundancy and routing-policy behavior.

Question 362.

What identifies a BGP route-reflector client?

1. External peer address
2. Cluster configuration
3. OSPF area number
4. NAT pool identifier

Correct Answer: 2

Explanation:

A route-reflector configuration identifies which internal BGP peers operate as clients of the reflector. The reflector then applies route-reflection behavior to routes learned from those clients according to its configuration. Cluster information can also be used in route-reflector designs to help prevent routing loops between reflectors. OSPF area numbers, NAT pool identifiers, and external peer addresses serve unrelated purposes. Understanding the client relationship is important because route reflection changes the normal internal BGP advertisement rules and allows selected routes to be distributed without requiring a complete internal peer mesh.

Question 363.

Which OSPF network type is commonly associated with Ethernet segments?

1. Point-to-point
2. Broadcast
3. Loopback
4. Serial

Correct Answer: 2

Explanation:

Ethernet networks are commonly treated as broadcast OSPF network segments. On such networks, OSPF can use multicast communication for neighbor discovery and elect a designated router and backup designated router to reduce the number of required adjacencies. The network type influences neighbor behavior, packet handling, and election requirements. Point-to-point is appropriate for direct point-to-point links, while loopback describes a logical interface rather than a typical multiaccess Ethernet segment. Serial is not the standard OSPF network type used to describe ordinary Ethernet connectivity.

Question 364.

Which OSPF mechanism reduces adjacency requirements on multiaccess networks?

1. Area authentication
2. Passive interfaces
3. DR election
4. Virtual links

Correct Answer: 3

Explanation:

OSPF designated-router election reduces the number of full adjacencies required on multiaccess networks such as Ethernet. Instead of every router establishing a full adjacency with every other router, routers establish relationships with the designated router and backup designated router. This reduces unnecessary control-plane exchanges and provides a more scalable flooding structure. Authentication protects OSPF exchanges, passive interfaces suppress neighbor formation on selected interfaces, and virtual links provide logical backbone connectivity. DR election therefore directly addresses adjacency scalability on multiaccess OSPF segments.

Question 365.

Which BGP mechanism helps prevent route-reflection loops?

1. Cluster list
2. MED attribute
3. Local preference
4. Origin code

Correct Answer: 1

Explanation:

The BGP cluster list helps prevent routing loops in environments using route reflectors. When a route reflector processes and reflects routes, cluster information can be added to the route. A reflector can examine the cluster list and reject a route if its own cluster identifier is already present, helping prevent the route from circulating between reflectors. MED, local preference, and origin are normal BGP path attributes but do not provide this specific loop-prevention function. Cluster-list processing is therefore an important safeguard in larger route-reflector deployments.

Question 366.

Which OSPF packet type is used to exchange link-state summaries?

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

Correct Answer: 2

Explanation:

OSPF Database Description packets provide summaries of the link-state database during adjacency establishment and synchronization. Routers use these packets to describe the link-state information they possess, allowing the neighbor to determine which specific link-state information may be missing. Hello packets discover and maintain neighbors, Link-State Requests ask for specific missing information, and Link-State Updates carry actual link-state advertisements. Understanding the distinction between these OSPF packet types is useful when troubleshooting adjacency formation and database synchronization problems between neighboring routers.

Question 367.

Which OSPF packet requests specific missing link-state information?

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

Correct Answer: 3

Explanation:

A Link-State Request packet is used when an OSPF router determines that it needs specific link-state information from its neighbor. During database synchronization, routers compare their available information and request missing or more recent link-state advertisements as necessary. Hello packets maintain neighbor relationships, Database Description packets summarize database contents, and Link-State Acknowledgment packets confirm receipt of link-state information. The Link-State Request therefore has a specific synchronization role: obtaining particular link-state advertisements needed to bring the local database into alignment with the neighbor.

Question 368.

Which OSPF packet confirms receipt of link-state information?

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

Correct Answer: 4

Explanation:

OSPF Link-State Acknowledgment packets confirm receipt of link-state advertisements. Reliable flooding is important because routers need confidence that link-state information has reached their neighbors. Acknowledgments allow the sender to determine whether the information was successfully received and whether retransmission may be necessary. Hello packets handle neighbor discovery and maintenance, Database Description packets summarize database contents, and Link-State Requests obtain specific missing information. Therefore, Link-State Acknowledgment serves the confirmation function during reliable OSPF link-state exchange and flooding.

Question 369.

What does a BGP route reflector primarily advertise to its clients?

1. Selected learned routes
2. Only connected networks
3. Only default routes
4. Interface statistics

Correct Answer: 1

Explanation:

A BGP route reflector distributes selected routes learned from its peers according to route-reflection rules and configured policies. This allows internal BGP clients to receive routes without requiring every client to establish a direct session with every other internal peer. The reflector does not inherently restrict advertisements to connected networks or default routes. Interface statistics are unrelated to BGP route advertisement. Route-reflector behavior can therefore improve scalability while still requiring careful policy design to control which routes are accepted and propagated throughout the internal BGP topology.

Question 370.

Which BGP feature identifies the reflector cluster context?

1. Router ID
2. Cluster ID
3. Peer AS
4. MED value

Correct Answer: 2

Explanation:

A BGP cluster ID identifies the route-reflector cluster context and participates in loop-prevention mechanisms involving route reflection. When multiple route reflectors are deployed, cluster information helps prevent reflected routes from circulating indefinitely between reflectors. Router ID uniquely identifies a BGP speaker, peer AS identifies the autonomous system relationship, and MED communicates a path preference to neighboring autonomous systems. Cluster ID therefore has a specialized role in route-reflector operation rather than ordinary external path selection or interface identification.

Question 371.

Which OSPF packet carries actual link-state advertisements?

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

Correct Answer: 1

Explanation:

An OSPF Link-State Update packet carries one or more link-state advertisements. These advertisements communicate topology information that routers use to construct and maintain their link-state databases. Hello packets are primarily used for neighbor discovery and maintenance, Database Description packets summarize database contents, and Link-State Requests ask neighbors for specific missing information. Link-State Updates therefore carry the actual topology information needed for database synchronization and network convergence. Correctly identifying these packet functions is useful when analyzing OSPF captures and troubleshooting incomplete or delayed routing information.

Question 372.

Which OSPF packet maintains neighbor relationships?

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

Correct Answer: 3

Explanation:

OSPF Hello packets are used to discover neighboring routers and maintain established neighbor relationships. They communicate parameters such as timers, area information, and other values that must be compatible for an adjacency to form. Regular Hello exchanges also allow routers to detect when a neighbor becomes unreachable after the configured dead interval. Database Description, Link-State Update, and Link-State Request packets serve different roles during link-state database synchronization. Hello packets therefore provide the foundation for OSPF neighbor discovery and ongoing adjacency maintenance.

Question 373.

Which BGP attribute can identify the autonomous systems crossed by a route?

1. Community
2. AS path
3. MED
4. Origin

Correct Answer: 2

Explanation:

The BGP AS path attribute records the sequence of autonomous systems through which a route has passed. It provides valuable information for path selection and also serves as an important loop-prevention mechanism. When a BGP router receives a route containing its own autonomous system number in the AS path, it can recognize that the route has already traversed that autonomous system and reject it according to normal processing. Communities provide administrative tags, MED communicates path preferences, and origin describes route introduction. AS path therefore provides the requested transit information.

Question 374.

What does BGP AS-path processing help prevent?

1. VLAN loops
2. Routing loops
3. DNS recursion
4. TCP fragmentation

Correct Answer: 2

Explanation:

BGP AS-path processing helps prevent routing loops between autonomous systems. As a route is advertised through BGP, autonomous system numbers are added to the AS path. When a router receives a route containing its own autonomous system number, it can identify that the route has already passed through its domain and reject the advertisement. This provides an important safety mechanism for interdomain routing. VLAN loops, DNS recursion, and TCP fragmentation are unrelated functions and are controlled by different protocols or mechanisms.

Question 375.

Which BGP property is normally increased when a route crosses an autonomous system?

1. AS path length
2. Interface priority
3. OSPF cost
4. TCP window

Correct Answer: 1

Explanation:

When a BGP route is advertised across an autonomous-system boundary, the advertising process normally adds the originating autonomous system to the AS path. As additional autonomous systems are traversed, the path becomes longer. AS-path length can influence BGP route selection, with shorter paths commonly preferred when the relevant decision stages are otherwise comparable. Interface priority belongs to other network functions, OSPF cost applies to OSPF path calculations, and TCP window controls transport flow. AS-path growth therefore reflects the number of autonomous-system hops represented by a BGP route.

Question 376.

Which OSPF database component describes a router’s local links?

1. Router-LSA
2. Network-LSA
3. Summary-LSA
4. External-LSA

Correct Answer: 1

Explanation:

A Router-LSA describes the links, interfaces, and associated information of an OSPF router within its area. It provides the local topology information that other routers use when constructing the area’s link-state database and calculating shortest paths. Network-LSAs describe multiaccess network segments through the designated router, while summary and external LSAs represent other types of reachability information. Router-LSAs are therefore fundamental to OSPF’s representation of the internal topology and are generated by participating routers to describe their own connections.

Question 377.

Which OSPF LSA represents a multiaccess network segment?

1. Router-LSA
2. Network-LSA
3. External-LSA
4. Summary-LSA

Correct Answer: 2

Explanation:

A Network-LSA represents a multiaccess network segment and is originated by the designated router for that segment. It describes the routers attached to the network, allowing the OSPF link-state database to represent the shared segment efficiently. Router-LSAs describe individual routers and their links, while Summary-LSAs communicate inter-area reachability and External-LSAs represent routes redistributed from outside the OSPF domain. Network-LSAs therefore provide the topology information required to represent a shared multiaccess network within the OSPF database.

Question 378.

Which OSPF LSA type normally carries external routing information?

1. Router-LSA
2. Network-LSA
3. External-LSA
4. Summary-LSA

Correct Answer: 3

Explanation:

External-LSAs describe routes that originate outside the OSPF routing domain and are introduced through route redistribution or other supported mechanisms. These advertisements allow OSPF routers to learn reachability toward destinations that are not native to the OSPF topology. Router-LSAs represent individual routers, Network-LSAs describe multiaccess segments, and Summary-LSAs communicate selected inter-area information. External-LSAs therefore serve a distinct role by representing externally sourced routing information within the OSPF link-state database and supporting reachability beyond the native OSPF topology.

Question 379.

Which OSPF LSA provides inter-area network reachability information?

1. Router-LSA
2. External-LSA
3. Network-LSA
4. Summary-LSA

Correct Answer: 4

Explanation:

Summary-LSAs provide inter-area reachability information within OSPF. They are associated with area border routers and allow networks from one OSPF area to be represented in another area without exposing the complete internal topology of the source area. Router-LSAs describe routers within an area, Network-LSAs describe shared network segments, and External-LSAs represent routes originating outside the OSPF domain. Summary-LSAs therefore support the hierarchical design of OSPF by communicating selected reachability information across area boundaries.

Question 380.

Which BGP attribute records the originating autonomous-system sequence?

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

Correct Answer: 3

Explanation:

The BGP AS path attribute records the sequence of autonomous systems associated with a route’s advertisement history. Each participating autonomous system can add its identifier as the route is propagated, creating a path that reflects the route’s interdomain traversal. This information is useful for path selection and loop prevention. Local preference controls internal outbound routing choices, MED can communicate preferred entry points, and communities provide administrative classification. AS path therefore specifically represents the autonomous-system sequence associated with a BGP route and its propagation through different routing domains.