JN0-106 User Interfaces Practice Test 5 — 15 Questions

Question 1

While in configuration mode, an engineer types 'show' and sees a different output than when typing 'run show configuration'. Why?

Accepted Answer

'show' shows the candidate configuration; 'run show configuration' shows the active configuration.. In Junos, when you are in configuration mode and type 'show', it displays the candidate configuration (the changes you have made but not yet committed). The command 'run show configuration' executes the operational-mode command 'show configuration' from within configuration mode, which displays the active (committed) configuration. Therefore, option B correctly identifies that 'show' shows the candidate configuration and 'run show configuration' shows the active configuration.

Answer

'show' shows the active configuration; 'run show configuration' shows the candidate.

Answer

Both commands produce identical output.

Answer

'run show configuration' is not allowed from configuration mode.

Question 2

A network engineer needs to revert to the configuration that was committed two commits ago. Which rollback number should they use?

Accepted Answer

rollback 2. The rollback command in Junos OS allows reverting to a previously committed configuration. The rollback number corresponds to the number of commits ago, starting with rollback 0 for the most recent commit, rollback 1 for the commit before that, and so on. Therefore, to revert to the configuration committed two commits ago, the correct rollback number is 2.

Answer

rollback 0

Answer

rollback 1

Answer

rollback 3

Question 3

A user wants to discard all uncommitted changes and return to the last committed configuration without exiting configuration mode. Which command should they use?

Accepted Answer

rollback 0. 'rollback 0' discards all uncommitted changes and reverts the candidate configuration to the last committed configuration, all while staying in configuration mode. In Junos, rollback 0 specifically refers to the most recently committed configuration, making it the exact command to undo uncommitted edits without exiting.

Answer

load override

Answer

reload

Answer

commit check

Question 4

During a maintenance window, an engineer makes critical changes and wants the configuration to automatically revert if they lose connectivity. Which command should they use before committing?

Accepted Answer

commit confirmed. 'commit confirmed', is correct because it allows the engineer to commit a configuration change with a default 10-minute rollback timer. If the engineer loses connectivity and does not confirm the commit within that period, the system automatically reverts to the previous configuration, ensuring the device remains reachable.

Answer

commit

Answer

commit check

Answer

commit at

Question 5

What permission bit must be included in a custom login class to allow a user to execute the ping command?

Accepted Answer

network. Network. In Junos, the 'network' permission bit controls access to network diagnostic commands such as ping, traceroute, and ssh. Without this permission, a user cannot execute these commands even if they have other permissions like view or control.

Answer

view

Answer

control

Answer

system

Question 6

An engineer needs to apply a configuration change to all interfaces except the management interface (fxp0). Which approach is most efficient?

Accepted Answer

Create a configuration group that includes all interfaces and use apply-groups-except to exclude fxp0.. Configuration groups with apply-groups-except allow you to define a common configuration template (e.g., all interfaces) and then selectively exclude specific interfaces (e.g., fxp0) from inheriting those settings. This approach is efficient, scalable, and avoids manual per-interface configuration or risky regex patterns that might inadvertently match unintended interfaces.

Answer

Manually configure each interface individually.

Answer

Use wildcard set with regex to match all interfaces except fxp0.

Answer

Use the 'set interfaces fxp0 disable' command and then apply changes to all interfaces.

Question 7

An engineer wants to view system log messages as they are generated in real-time. Which command should they use?

Accepted Answer

monitor log messages. The 'monitor log messages' command in Junos OS provides a real-time view of system log messages as they are generated, similar to the 'tail -f' command on Unix systems. It streams new log entries to the terminal without requiring manual refresh, making it ideal for live monitoring of events.

Answer

start log messages

Answer

request system log

Answer

show log messages

Question 8

Which TWO statements are true about commit operations in Junos? (Choose two.)

Accepted Answer

The commit command requires the candidate configuration to be syntactically correct.. The `commit` command in Junos requires the candidate configuration to pass syntax and commit script checks before it is applied to the running system. If the configuration contains errors, the commit will fail, ensuring that only valid configurations are activated.

Answer

The rollback 0 command will cause a system reboot.

Answer

The commit check command applies the configuration to the running system.

Answer

The commit at command is used to schedule a system reboot.

Question 9

Which THREE pipe modifiers can be used to filter command output? (Choose three.)

Accepted Answer

count. The 'count' pipe modifier in Junos counts the number of lines in the command output, effectively filtering by providing a numeric summary rather than displaying the actual lines. This is a valid pipe modifier used to filter or transform command output in the Junos CLI.

Answer

no-more

Answer

display set

Question 10

Which TWO commands can be used to enter configuration mode from operational mode? (Choose two.)

Accepted Answer

edit. The 'edit' command is correct because it is the primary method to enter configuration mode from operational mode in Junos OS. When you type 'edit' at the operational mode prompt, you are placed into configuration mode, where you can modify the candidate configuration. This command is equivalent to 'configure' and is commonly used for entering the configuration hierarchy.

Answer

set

Answer

config

Answer

terminal

Question 11

Refer to the exhibit. Based on the output, which statement is true?

Accepted Answer

The router hostname is router1.. The output shows the system prompt ending with 'router1>', which indicates the hostname is set to 'router1'. In Junos, the CLI prompt format is 'hostname>', so this directly confirms the router hostname. Option D is correct because the prompt explicitly displays 'router1' as the active hostname.

Answer

The admin user has read-only access.

Answer

The interface ge-0/0/0 has been disabled.

Answer

The root password is stored in plaintext.

Question 12

You are a network administrator for a large service provider. You have a Juniper MX960 that serves as a core router. The router uses a configuration with many apply-groups to streamline management. Recently, you added a new apply-group for interface-specific policies. After committing, several interfaces stopped passing traffic due to incorrect policy application. You need to quickly revert to the previous configuration without losing other valid changes made by other engineers in the same commit. The previous configuration is stored as rollback 1. However, rollback 1 contains configuration that does not include the new apply-group but also includes other valid changes from the last commit. You want to restore the configuration to exactly the state before the last commit (the rollback 1 state). Which command should you use?

Accepted Answer

load override rollback 1 and commit. 'load override rollback 1' replaces the entire candidate configuration with the exact contents of rollback 1, which is the state before the last commit. This allows you to revert the problematic apply-group change while preserving all other valid changes that were part of that same rollback snapshot. A subsequent 'commit' then activates this configuration, effectively undoing only the last commit without affecting earlier valid changes.

Answer

rollback 0 and commit check

Answer

rollback 0 and then commit

Answer

request system configuration rescue save and then load rescue

Question 13

A network engineer is troubleshooting a BGP session that is not establishing. They want to see the BGP configuration details for peer 10.0.0.1. They type 'show configuration protocols bgp group external peer 10.0.0.1' but receive 'error: syntax error'. They are in operational mode. What is the most likely issue?

Accepted Answer

The keyword 'peer' should be 'neighbor'.. In Junos OS, the correct keyword to reference a BGP peer in operational mode commands is 'neighbor', not 'peer'. The command 'show configuration protocols bgp group external neighbor 10.0.0.1' would display the configuration for that specific peer. Using 'peer' causes a syntax error because Junos does not recognize that keyword in this context.

Answer

The peer IP 10.0.0.1 is not configured on the device.

Answer

The command should be 'show configuration protocols bgp group external | match 10.0.0.1'.

Answer

They need to enter configuration mode first.

Question 14

Which two commands can be used to view the candidate configuration in set format? (Choose two.)

Accepted Answer

show | display set (in configuration mode). In configuration mode, the 'show | display set' command outputs the candidate configuration as a series of 'set' commands, which is a compact and script-friendly format. Option D is also correct because the same output can be achieved in operational mode using 'show configuration | display set', which displays the candidate configuration from the operational CLI context.

Answer

show configuration | display set | no-parenthesis

Answer

show | set

Answer

show configuration | display inherited

Question 15

Which three statements about JunOS CLI pipe commands are true? (Choose three.)

Accepted Answer

The '| match' pipe filter displays lines that match a regular expression.. The '| match' pipe filter in JunOS uses a regular expression to display only those lines in the output that contain a match. This is a standard filtering mechanism that allows operators to quickly isolate relevant configuration or operational data without scrolling through entire command output.

Answer

The '| resolve' pipe filter resolves IP addresses to hostnames.

Answer

The '| display set' pipe filter converts operational output to set format.