Practice Free JN0-106 Exam Online Questions
Which two actions happen when multiple users issue the configure exclusive command to enter configuration mode on a Junos device? (Choose two.)
- A . Other users can enter configuration mode.
- B . The candidate configuration is unlocked.
- C . The candidate configuration is locked.
- D . Other users cannot enter configuration mode.
C, D
Explanation:
In Junos OS, when a user issues the configure exclusive command, it locks the candidate configuration for that user, preventing other users from making concurrent configuration changes. This exclusive lock ensures that configuration changes are managed in a controlled manner, reducing the risk of conflicting changes. As a result, while one user is in exclusive configuration mode, other users are prevented from entering configuration mode until the lock is released, either by the user committing the changes or exiting configuration mode.
A network administrator is attempting to route traffic on a Juniper switch to one of three different VLANs: Prod, Test, and Dev. Each VLAN has been assigned a numerical value.
In this scenario, what are these numerical values called?
- A . defaults
- B . interfaces
- C . names
- D . tags
D
Explanation:
In the context of VLANs (Virtual Local Area Networks) on a Juniper switch, the numerical values assigned to each VLAN, such as those for Prod, Test, and Dev, are known as VLAN tags. These tags are part of the 802.1Q VLAN standard, which allows multiple VLANs to coexist on a single physical network. Each tag uniquely identifies the VLAN to which a frame belongs, enabling the switch to segregate and manage traffic based on VLAN membership. This tagging mechanism allows for efficient traffic separation and management, ensuring that devices within one VLAN do not receive traffic intended for another, thus maintaining network security and efficiency.
Which criteria does the Junos OS use to select an active route when two entries exist in the routing table?
- A . the route with the lowest preference number
- B . the most recently learned dynamic route
- C . the route with the highest preference number
- D . the route with the highest metric
A
Explanation:
In Junos OS, when two entries for the same destination exist in the routing table, the route with the lowest preference number is selected as the active route. This preference number, also known as the route preference or administrative distance, is used to prioritize routes received from different routing protocols.
You have logged on to a Junos device and are at the operational mode prompt.
Which two commands are used at this prompt? (Choose two.)
- A . show interface ge-0/0/0
- B . request system shutdown
- C . set interface ge-0/0/0 unit 0 family inet
- D . run show interface terse
AB
Explanation:
At the operational mode prompt on a Junos device, you can use various commands to view the device’s status and request system operations. The show interface ge-0/0/0 command is used to display information about a specific interface, while the request system shutdown command is used to properly shut down the device. The set command is used in configuration mode, not operational mode, and the run command is used to execute operational mode commands from configuration mode.
What information would you find using the CLI help command?
- A . hyperlinks for remediation actions
- B . a URL for accessing the technical documentation
- C . an explanation for specific system log error messages
- D . message of the day
C
Explanation:
The CLI help command in Junos OS provides assistance and explanations for commands, command options, and in some cases, specific system log error messages. By using the help command followed by specific keywords or messages, users can get detailed information and context for the commands they are using or errors they are encountering. This feature is particularly useful for understanding the purpose of commands, their syntax, and troubleshooting error messages that may appear in system logs.
What is the protocol data unit (PDU) of the Data Link Layer?
- A . segment
- B . byte
- C . frame
- D . bit
C
Explanation:
In the OSI model, the Data Link Layer is responsible for node-to-node delivery of data. It frames the packets received from the Network Layer and prepares them for physical transmission. The Protocol Data Unit (PDU) for the Data Link Layer is called a "frame." Frames encapsulate the network layer packets, adding a header and a trailer that include the hardware addresses of the source and destination, among other things, facilitating the data link layer services like frame synchronization, flow control, and error checking.
You want to configure the management port on a Juniper device. In this scenario, what is the management interface name?
- A . st0
- B . fxp0
- C . mt0
- D . mtun0
B
Explanation:
In Junos OS, the dedicated out-of-band management interface is typically named fxp0. This interface is used exclusively for management traffic and is physically separated from the data traffic interfaces. It allows administrators to perform management tasks even when the device is experiencing issues that affect the forwarding plane.
From the JNCIA-Junos Study Guide and Junos OS Documentation:
“The fxp0 interface is a dedicated management interface that provides out-of-band management access. It is commonly found on Juniper routers, switches, and security platforms. You assign IP addresses to this interface as you would any other, and it is often used to connect to a management network or to allow SSH, Telnet, or SNMP access.”
― Junos OS Fundamentals, Chapter: Interfaces
― Junos OS Documentation: Management Interfaces Overview
― JNCIA-Junos Exam Objective: Interface Types
Reference: Junos OS Fundamentals Guide JNCIA-Junos Exam Objectives (JN0-105)
Junos Interface Naming Conventions, Juniper TechLibrary
What are two functions of the routing protocol daemon (rpd)? (Choose two.)
- A . It generates chassis alarms.
- B . It provides access to the CLI.
- C . It creates forwarding tables.
- D . It maintains routing tables.
C, D
Explanation:
The Routing Protocol Daemon (rpd) is a critical component in Juniper Networks devices, responsible for all routing operations. It maintains routing tables, which hold information about network paths and destinations derived from various routing protocols. These tables are used to make decisions about where to send packets. Additionally, rpd generates forwarding tables based on the information in the routing tables. The forwarding tables are then used by the Packet Forwarding Engine (PFE) to actually forward packets to their next hop or final destination.
What are two link-state routing protocols? (Choose two.)
- A . RIP
- B . BGP
- C . OSPF
- D . IS-IS
C, D
Explanation:
Link-state routing protocols are a type of routing protocol used in packet-switching networks for finding the best path between source and destination. OSPF (Open Shortest Path First) and IS-IS (Intermediate System to Intermediate System) are both examples of link-state routing protocols. They work by maintaining a complete map or topology of the network, allowing routers to independently calculate the best path to each destination. Unlike distance-vector protocols like RIP, link-state protocols are more efficient and scalable, making them suitable for larger networks.
Which component is considered part of the data plane?
- A . the Routing Engine
- B . the Packet Forwarding Engine
- C . the power supply
- D . the fan tray
B
Explanation:
The Packet Forwarding Engine (PFE) is an integral component of Juniper Networks devices, responsible for the data plane operations. The data plane, also known as the forwarding plane, is where the actual processing and forwarding of packets occur based on the routing and forwarding tables. The PFE executes the forwarding decisions made by the Routing Engine (RE), handling all packet transmissions, including routing, filtering, and switching packets towards their destination. This contrasts with the control plane operations handled by the RE, which involve routing table maintenance, system management, and control protocol processing.
