View Full Juniper JN0-106 Exam Dumps and Practice Test Dumps.

 

Question 1

Which Junos OS component is primarily responsible for maintaining the routing table and making routing decisions?

1. Routing Engine
2. Packet Forwarding Engine
3. Interface Module
4. Power Supply Module

Correct Answer: 1

Explanation

The Routing Engine is responsible for control-plane operations in Junos OS, including maintaining routing information and making routing decisions. It runs routing protocols, processes routing updates, and builds the routing table used by the system. Once routes are calculated, forwarding information is communicated to the Packet Forwarding Engine. The Packet Forwarding Engine then handles packet forwarding based on that information. Understanding the distinction between the Routing Engine and Packet Forwarding Engine is important when learning Juniper architecture because they perform different but complementary functions within a Junos device.

Question 2

Which command is used to display the current configuration in Junos OS?

1. show interfaces
2. show route
3. show configuration
4. show system information

Correct Answer: 3

Explanation

The show configuration command is used from operational mode to display the active configuration of a Junos device. It provides a hierarchical view of configured statements, including interfaces, routing protocols, system settings, security policies, and other configuration elements. This command is commonly used when administrators need to review the current configuration before making changes or troubleshooting an issue. Junos separates operational and configuration modes, so understanding which commands belong to each mode is essential. The show configuration command provides a useful overview of the configuration currently committed and active on the device.

Question 3

Which Junos OS command is used to enter configuration mode?

1. configure
2. edit
3. set
4. commit

Correct Answer: 1

Explanation

The configure command is used to move from operational mode into configuration mode in Junos OS. Once in configuration mode, administrators can create, modify, or delete configuration statements. Commands such as set, delete, and edit can then be used to make configuration changes. Changes made in configuration mode are not immediately active; they normally require a commit operation before becoming part of the active configuration. This separation between operational and configuration modes helps administrators manage changes carefully and provides mechanisms for reviewing configurations before applying them to the running system.

Question 4

Which command commits configuration changes and makes them active in Junos OS?

1. save
2. apply
3. activate
4. commit

Correct Answer: 4

Explanation

The commit command activates configuration changes in Junos OS. Administrators normally make changes in configuration mode and then use commit to validate and apply those changes to the active configuration. Junos performs configuration checks during the commit process, helping prevent invalid configurations from becoming active. If errors are detected, the commit operation can fail and the administrator can correct the configuration before trying again. This commit-based configuration model is an important feature of Junos OS because it allows changes to be reviewed and prepared before they affect the operational device.

Question 5

Which Junos OS mode provides access to operational commands used for monitoring and troubleshooting?

1. Configuration mode
2. Operational mode
3. Edit mode
4. Maintenance mode

Correct Answer: 2

Explanation

Operational mode is the primary environment for monitoring, troubleshooting, and viewing information about a Junos device. When administrators log in to a Junos device, they normally begin in operational mode. Commands such as show, ping, traceroute, and monitor are commonly used there. Configuration mode is different because it is intended for modifying the device configuration. Keeping operational and configuration activities separate helps reduce accidental changes while administrators are performing monitoring tasks. Understanding this distinction is fundamental when working with Junos OS and is frequently tested in entry-level Juniper certification topics.

Question 6

Which command displays information about the routes currently known by a Junos device?

1. show interfaces
2. show route
3. show chassis hardware
4. show users

Correct Answer: 2

Explanation

The show route command displays routing information maintained by the Junos device. It can be used to examine routes learned from directly connected networks, static routes, and dynamic routing protocols. Administrators frequently use this command when troubleshooting connectivity and verifying whether a particular destination exists in the routing table. Additional options can provide more detailed information about specific routes or protocols. Understanding routing-table output is an important networking skill because it helps determine how traffic will be forwarded toward a destination and whether the expected route has been successfully installed.

Question 7

Which Junos OS command can be used to test reachability to a remote IP address?

1. ping
2. commit
3. rollback
4. configure

Correct Answer: 1

Explanation

The ping command is used to test basic IP connectivity between the Junos device and a specified destination. It sends Internet Control Message Protocol echo requests and waits for responses from the destination. Successful responses generally indicate that the destination is reachable at the network layer, although they do not guarantee that every application or service is functioning correctly. Ping is therefore commonly used as an initial troubleshooting tool. Administrators can also specify options such as a source address or interface when testing more specific connectivity scenarios.

Question 8

Which Junos OS feature allows an administrator to return to a previously committed configuration?

1. rescue
2. rollback
3. refresh
4. recover

Correct Answer: 2

Explanation

The rollback feature allows administrators to return to a previous committed configuration in Junos OS. Junos maintains a history of committed configurations, making it possible to revert changes when a recent modification causes an unexpected problem. The rollback command can be used in configuration mode to load an earlier configuration, after which the administrator can review it and commit it if appropriate. This capability is particularly useful during maintenance and troubleshooting because it provides a controlled way to undo configuration changes without manually reconstructing the previous settings.

Question 9

Which Junos component performs high-speed packet forwarding?

1. Routing Engine
2. Packet Forwarding Engine
3. Management Console
4. Configuration Database

Correct Answer: 2

Explanation

The Packet Forwarding Engine is responsible for forwarding packets through a Junos device. It uses forwarding information provided by the control plane to determine where packets should be sent. This separation allows the Routing Engine to focus on control-plane functions such as routing protocols and system management while the Packet Forwarding Engine handles data-plane traffic. Depending on the Juniper platform, forwarding may be implemented using specialized hardware or other platform-specific technologies. Understanding this division between control and forwarding functions is essential for understanding Juniper router and switch architecture.

Question 10

Which command displays detailed information about Junos interfaces?

1. show route
2. show version
3. show interfaces
4. show configuration

Correct Answer: 3

Explanation

The show interfaces command provides information about interfaces configured and operating on a Junos device. Depending on the command options, the output can include interface status, IP addressing, traffic statistics, errors, packet counts, and other operational information. Administrators commonly use this command when troubleshooting connectivity, checking interface health, or verifying whether an interface is physically and logically operational. The command is available from operational mode and supports additional options for examining a specific interface or obtaining more detailed information about interface operation.

Question 11

Which command displays the Junos OS version running on a device?

1. show version
2. show route
3. show chassis
4. show system users

Correct Answer: 1

Explanation

The show version command displays information about the Junos OS software installed on the device. The output can include the Junos release version, operating system details, and platform information. Administrators commonly use this command when troubleshooting compatibility issues, verifying software versions, or preparing for software upgrades. Knowing the exact Junos version is important because commands, features, and behavior can vary between releases. This command is therefore one of the basic operational commands that network administrators should understand when managing Juniper devices.

Question 12

Which command can be used to display the users currently logged into a Junos device?

1. show system alarms
2. show system users
3. show system processes
4. show system uptime

Correct Answer: 2

Explanation

The show system users command displays information about users who are currently logged into the Junos device. It can help administrators identify active sessions and determine which users are accessing the system. This information can be useful during troubleshooting, maintenance, or security investigations. Junos provides several show system commands for monitoring different aspects of device operation, including users, processes, alarms, and uptime. Knowing the appropriate command allows administrators to quickly obtain the operational information needed without modifying the device configuration.

Question 13

Which Junos OS command is commonly used to test the path packets take toward a destination?

1. ping
2. traceroute
3. monitor
4. telnet

Correct Answer: 2

Explanation

The traceroute command is used to identify the network path packets take toward a destination. Unlike ping, which primarily tests reachability, traceroute can reveal intermediate routing devices between the source and destination. This makes it useful for identifying routing problems, unexpected paths, or points where packets may stop progressing. Junos supports traceroute as an operational troubleshooting command. Network administrators often use it together with ping and routing-table commands to investigate connectivity problems and determine whether traffic is following the expected path through the network.

Question 14

What is the primary purpose of a routing protocol?

1. Assign usernames
2. Discover and exchange routing information
3. Configure hardware power settings
4. Display interface descriptions

Correct Answer: 2

Explanation

A routing protocol allows network devices to exchange information about reachable networks and determine appropriate paths for forwarding traffic. Examples include OSPF, IS-IS, BGP, and RIP. Depending on the protocol, devices exchange routing information with neighboring routers and use defined algorithms or policies to select routes. The resulting information can then be installed in the routing table and used to build forwarding information. Routing protocols are essential in larger networks because manually configuring every route would be difficult to maintain as the network grows and changes.

Question 15

Which protocol is commonly used as an interior gateway protocol based on a link-state algorithm?

1. BGP
2. FTP
3. OSPF
4. SSH

Correct Answer: 3

Explanation

OSPF, or Open Shortest Path First, is a link-state interior gateway protocol commonly used within an organization or autonomous system. OSPF routers exchange link-state information and build a database describing the network topology. They then use the Shortest Path First algorithm to calculate routes. OSPF supports hierarchical network design through areas, which can help improve scalability. BGP serves a different purpose as an exterior gateway protocol, while FTP and SSH are application-layer protocols. Understanding the role of OSPF is important for basic Junos routing and network administration concepts.

Question 16

Which protocol is primarily used to exchange routing information between autonomous systems?

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

Correct Answer: 2

Explanation

Border Gateway Protocol, or BGP, is primarily used to exchange routing information between autonomous systems. It is classified as an exterior gateway protocol and is fundamental to Internet routing. BGP uses path attributes and routing policies to select and advertise routes rather than relying solely on a shortest-path calculation. Junos devices support BGP for both Internet connectivity and large enterprise or service-provider networks. Understanding the distinction between internal routing protocols such as OSPF and external routing protocols such as BGP is an important part of foundational Juniper networking knowledge.

Question 17

Which protocol securely provides remote command-line access to a Junos device?

1. HTTP
2. FTP
3. SSH
4. TFTP

Correct Answer: 3

Explanation

SSH, or Secure Shell, provides encrypted remote command-line access to Junos devices. It protects login credentials and session data by encrypting communication between the administrator and the device. SSH is widely preferred for remote management because protocols such as traditional Telnet transmit information without strong encryption. Administrators can use SSH to access the Junos CLI remotely and perform monitoring, troubleshooting, and configuration tasks according to their permissions. Proper authentication and access-control settings should also be used to protect management access to network infrastructure.

Question 18

What does the Junos commit process primarily do?

1. Deletes all inactive configuration statements
2. Validates and activates configuration changes
3. Restarts the Routing Engine
4. Clears the routing table

Correct Answer: 2

Explanation

The Junos commit process validates the candidate configuration and, when successful, makes the changes active on the device. This is a key characteristic of Junos configuration management. Administrators can prepare multiple changes in configuration mode and then commit them as a controlled configuration update. If the configuration contains errors that prevent a successful commit, Junos reports the problem and does not activate the invalid configuration. This approach reduces the risk of accidentally applying incomplete or syntactically incorrect configuration statements to a production device.

Question 19

Which Junos command can display hardware information about the device chassis?

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

Correct Answer: 1

Explanation

The show chassis hardware command displays hardware-related information about a Juniper device. Depending on the platform, the output can identify chassis components, installed modules, routing engines, line cards, and other hardware elements. Administrators can use this information when verifying installed hardware or troubleshooting hardware-related issues. It is different from commands that display software configuration or routing information. Understanding basic chassis commands is useful for network administrators who need to identify the physical components installed in a Junos-based device.

Question 20

Which Junos command provides a concise summary of interface status and addressing information?

1. show route summary
2. show interfaces terse
3. show system users
4. show configuration interfaces

Correct Answer: 2

Explanation

The show interfaces terse command provides a concise summary of interface information. It is useful for quickly checking whether interfaces are administratively enabled, whether they are physically and logically operational, and what addresses may be configured. Compared with the more detailed show interfaces command, the terse version presents information in a compact format that is convenient when reviewing many interfaces at once. Network administrators often use it as an initial troubleshooting command before examining a specific interface in greater detail. It is especially useful for quickly identifying interfaces that may be down or incorrectly configured.