Juniper JN0-105 Online Practice Questions and Exam Preparation

Juniper JN0-105 Online Questions & Answers

• Question 101:

  Refer to the exhibit.

  

  A customer reports that they have recently lost connectivity to a remote site over a shared architecture.

  Referring to the exhibit, what is the problem?

  A. The remote link is down.
  B. The remote router has been powered off.
  C. The authentication method or key has been changed.
  D. The remote site router has been configured for OSPF.
  C. The authentication method or key has been changed.

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  Explanation

• Question 102:

  Which layer of the OSI model contains the IP address information?

  A. Layer 2
  B. Layer 4
  C. Layer 1
  D. Layer 3
  D. Layer 3

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  Explanation

  The OSI (Open Systems Interconnection) model is a conceptual framework used to understand network interactions in seven distinct layers. IP (Internet Protocol) addresses are part of Layer 3, known as the Network Layer. This layer is responsible for packet forwarding, including routing through intermediate routers, and it handles the logical addressing scheme of the network to ensure that packets can be routed across multiple networks and reach their destination. IP addresses provide unique identifiers for network interfaces, allowing for communication between devices on a network or across different networks.

• Question 103:

  When considering routing tables and forwarding tables, which two statements are correct? (Choose two.)

  A. The routing table is used by the RE to select the best route.
  B. The forwarding table stores all routes and prefixes from all protocols.
  C. The forwarding table is used by the RE to select the best route.
  D. The routing table stores all routes and prefixes from all protocols.
  A. The routing table is used by the RE to select the best route.
  D. The routing table stores all routes and prefixes from all protocols.

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  Explanation

  The routing table and forwarding table play distinct roles in a Junos OS device. The correct answers are A and

  D. The routing table (A) is used by the Routing Engine (RE) to select the best route among all the learned routes, while the routing table (D) stores all routes and prefixes learned from all routing protocols. The forwarding table, in contrast, contains only the active routes chosen by the RE and is used by the Packet Forwarding Engine for actual packet forwarding.

• Question 104:

  Which layer of the OSI model does a router use to make forwarding decisions?

  A. Layer 3
  B. Layer 4
  C. Layer 5
  D. Layer 2
  A. Layer 3

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  Explanation

• Question 105:

  A packet enters a Junos device. No matching destination entry exists in the forwarding table. How will the device respond?

  A. The RE responds to the source with a destination unreachable notification message
  B. The PFE responds to the destination with a source unreachable notification message
  C. The PFE responds to the source with a destination unreachable notification message
  D. The RE responds to the destination with a source unreachable notification message
  B. The PFE responds to the destination with a source unreachable notification message

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  Explanation

• Question 106:

  Which statement is correct concerning exception traffic processing?

  A. Exception traffic is discarded by the PFE.
  B. Exception traffic is rate-limited to protect the RE.
  C. Exception traffic is always dropped during congestion.
  D. Exception traffic is never forwarded.
  B. Exception traffic is rate-limited to protect the RE.

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  Explanation

  Exception traffic refers to packets that the Packet Forwarding Engine (PFE) cannot process normally and must be forwarded to the Routing Engine (RE) for further processing. This includes packets destined for the router itself or packets needing special handling that the PFE cannot provide. To protect the RE from being overwhelmed by such traffic, which could potentially impact the router's control plane functions, exception traffic is rate-limited. This means that there's a threshold to how much exception traffic can be sent to the RE, ensuring that the router's critical management and control functions remain stable and responsive even during high traffic volumes or attacks.

• Question 107:

  Which service does RADIUS provide?

  A. routing
  B. authentication
  C. DNS resolution
  D. time synchronization
  B. authentication

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  Explanation

  RADIUS, which stands for Remote Authentication Dial-In User Service, provides authentication services for users trying to access a network. It is a networking protocol that provides centralized Authentication, Authorization, and Accounting (AAA) management for users who connect and use a network service.

• Question 108:

  Which two statements describe the default behavior for OSPF? (Choose two)

  A. OSPF imports all routes into the inet4.0 routing table.
  B. OSPF exports all static routes into the OSPF database.
  C. OSPF imports all routes into the inet.O routing table.
  D. OSPF does not export static routes into the OSPF database.
  C. OSPF imports all routes into the inet.O routing table.
  D. OSPF does not export static routes into the OSPF database.

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  Explanation

• Question 109:

  Click the Exhibit button.

  

  Referring the exhibit, what does the highlighted number indicate?

  A. hop count is 5
  B. cost is 5
  C. metric is 5
  D. route preference is 5
  D. route preference is 5

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  Explanation

  In the exhibit shown, the highlighted number next to the route type (Static) within the square brackets indicates the route preference, also known as the administrative distance. In Junos, the route preference is a value that determines the priority of the route source. Lower numbers indicate a higher priority when the routing table is being calculated. The route preference is used to select the best route when multiple paths to the same destination exist from different routing sources. The number 5 is unusually low for a static route by default, suggesting it has been manually configured to override other route types.

• Question 110:

  Which protocol would you configure to synchronize the time and date on a Junos device?

  A. SNMP
  B. RIP
  C. NTP
  D. NMP
  C. NTP

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  Explanation

  The Network Time Protocol (NTP) is designed to synchronize the clocks of computers over a network. Configuring NTP on a Junos device ensures that its clock is set accurately, which is crucial for logging, troubleshooting, and maintaining the integrity of time-sensitive operations and security protocols. NTP allows devices to use a hierarchy of time sources, from primary servers synchronized to a reference clock (such as an atomic clock or GPS time) to secondary servers that distribute the time to other devices on the network.