JN0-106 Junos Configuration Basics Practice Test 4 — 15 Questions

Question 1

Which TWO commands can be used to view the current configuration on a Juniper device?

Accepted Answer

show configuration. 'show configuration' displays the candidate configuration, which is the current working configuration. To also see configuration inherited from groups, use 'show configuration | display inherited'. Both commands are valid for viewing the current configuration. The 'show configuration | display active' command (not listed) is specifically for the active running configuration.

Answer

show interfaces terse

Answer

show|display set | match

Answer

show active configuration

Question 2

A network administrator wants to add a new interface configuration to the candidate configuration while preserving all existing candidate changes. Which command should be used?

Accepted Answer

load merge terminal. Both 'load merge terminal' and 'load set terminal' merge configuration into the candidate without discarding existing changes. 'load merge terminal' expects configuration in the same format as the active configuration, while 'load set terminal' accepts set commands. Since the question does not specify the input format, both A and D are valid answers.

Answer

load replace terminal

Answer

load override terminal

Question 3

Which operational mode command displays the differences between the candidate configuration and the active configuration?

Accepted Answer

show configuration | compare. The 'show configuration | compare' command displays the differences between the candidate configuration and the active (committed) configuration. The pipe to 'compare' is a Junos CLI filter that performs a diff operation, showing lines added, changed, or deleted. This is the standard way to review uncommitted changes before committing them.

Answer

show | display set

Answer

show system configuration | compare

Answer

show | compare

Question 4

An engineer needs to configure a static route on a Juniper device. Which statement is true regarding the configuration process?

Accepted Answer

Configuration changes must be committed to become active.. In Junos, configuration changes are made in a candidate configuration and do not take effect until explicitly committed using the 'commit' command. This two-phase model (edit then commit) ensures that changes are validated before activation, preventing partial or incorrect configurations from disrupting network operations. Option B correctly identifies this requirement.

Answer

The set command activates the change for 10 minutes by default.

Answer

The configuration is immediately active upon entering the set command.

Answer

The commit command requires a reboot to take effect.

Question 5

After a series of configuration changes, an engineer wants to see only the lines that will be added or modified when the candidate is committed. Which command achieves this?

Accepted Answer

show | compare. The 'show | compare' command displays the differences between the candidate configuration and the active configuration, showing only the lines that will be added, modified, or deleted upon commit. This is the standard Junos method for reviewing pending changes before committing them.

Answer

show configuration | except

Answer

show configuration | display set

Answer

commit check | match

Question 6

Which command saves the active configuration to a file name other than the default rescue configuration?

Accepted Answer

file copy /config/juniper.conf.gz /var/tmp/backup.conf. The `file copy` command copies the active configuration file (`/config/juniper.conf.gz`) to a user-specified destination, such as `/var/tmp/backup.conf`, effectively saving the active configuration under a different filename. The rescue configuration is a special saved configuration that can be loaded with `rollback rescue`, but the question asks for saving to a file name other than the default rescue configuration, which is achieved by copying the active configuration file directly.

Answer

request system configuration rescue save

Answer

save configuration to file

Answer

commit and-quit

Question 7

An engineer issues the 'rollback 3' command in configuration mode. What is the effect?

Accepted Answer

The candidate configuration is replaced with the configuration from three commits ago.. The 'rollback 3' command in Junos configuration mode replaces the current candidate configuration with the configuration from the third most recent commit. Junos maintains up to 50 rollback slots (numbered 0 through 49), where slot 0 is the most recent commit, slot 1 is the commit before that, and so on. Therefore, 'rollback 3' retrieves the configuration saved three commits ago, overwriting any uncommitted changes in the candidate configuration.

Answer

The candidate configuration is saved as the third rollback slot.

Answer

The active configuration is replaced with the candidate configuration.

Answer

The device reboots and loads configuration version 3.

Question 8

A junior administrator is told to implement configuration changes that must survive a reboot. Which statement is correct?

Accepted Answer

Performing a 'commit' saves the active configuration to non-volatile storage.. In Junos, the 'commit' command activates the candidate configuration and saves it to non-volatile storage (the /config directory on the flash drive), ensuring it survives a reboot. This is the standard method for making configuration changes persistent across system restarts.

Answer

The 'commit confirmed' command ensures persistence.

Answer

Changes made using 'set' commands are automatically saved to the startup config.

Answer

The 'commit' command only writes to RAM, so a 'request system configuration save' is needed.

Question 9

Which THREE statements about commit options are true?

Accepted Answer

'commit confirmed' requires a second commit within the timeout to keep the changes.. The 'commit confirmed' command in Junos applies candidate configuration changes temporarily, and if a second commit (or 'commit check') is not performed within the default 10-minute timeout, the system automatically rolls back to the previous configuration. This is used to prevent lockout during remote management changes.

Answer

'commit full' reinitializes the system.

Answer

'commit and-quit' commits and exits configuration mode.

Question 10

Refer to the exhibit. What will happen if the engineer commits this configuration?

Accepted Answer

The interface will support both IPv4 and IPv6 traffic.. The configuration shown includes both `family inet` and `family inet6` under the same interface. Junos allows multiple address families to coexist on a single interface, enabling the interface to process both IPv4 and IPv6 traffic simultaneously. This is a standard feature of Junos, not an error.

Answer

The interface will have two primary IP addresses.

Answer

The configuration will fail because inet and inet6 cannot coexist.

Answer

Only the family inet will be applied.

Question 11

Refer to the exhibit. What is the effect of the pending changes?

Accepted Answer

The IP address 10.0.0.2 will be replaced by 10.0.0.1 after commit.. The candidate configuration shows that the IP address 10.0.0.2 is being deleted and replaced with 10.0.0.1 on interface ge-0/0/0. In Junos, pending changes are staged in the candidate configuration and only take effect after a commit. The 'replace:' tag indicates that the existing address 10.0.0.2 will be removed and 10.0.0.1 will be added upon commit.

Answer

The comparison shows no changes.

Answer

The interface will have two IP addresses: 10.0.0.1 and 10.0.0.2.

Answer

The candidate configuration will be empty after commit.

Question 12

A junior administrator wants to discard all uncommitted changes made in the current configuration session. Which command accomplishes this?

Accepted Answer

rollback 0. The `rollback 0` command reverts the candidate configuration to the active committed configuration, effectively discarding all uncommitted changes made during the current session. In Junos, configuration changes are stored in a candidate configuration until explicitly committed; `rollback 0` loads the last committed configuration (index 0) into the candidate, wiping out any uncommitted edits.

Answer

commit check

Answer

load factory-default

Answer

clear configuration

Question 13

An engineer needs to add a set of configuration parameters to a group that can be inherited by multiple interfaces. Which configuration element should be used?

Accepted Answer

configuration groups with apply-groups. Configuration groups with apply-groups allow you to define a set of configuration parameters in a named group and then apply that group to multiple interfaces (or other hierarchy levels) using the 'apply-groups' statement. This enables inheritance and reduces repetitive configuration, which is the exact requirement in the question.

Answer

prefix lists

Answer

set default

Answer

load merge

Question 14

An administrator wants to save the current configuration as a rescue configuration. Which command sequence is correct?

Accepted Answer

request system configuration rescue save. The correct command sequence to save the current configuration as a rescue configuration in Junos is 'request system configuration rescue save'. This command stores a copy of the active configuration as a rescue configuration, which can be loaded later using 'request system configuration rescue recover' if the device becomes unreachable or the configuration is corrupted. The rescue configuration is stored in a special file (rescue.conf.gz) and is not overwritten by normal commits.

Answer

copy configuration rescue

Answer

save rescue-config

Answer

commit rescue

Question 15

A network administrator needs to temporarily disable a set of configuration statements for testing without deleting them. Which approach should be used?

Accepted Answer

use the 'deactivate' command to mark the statements inactive. The 'deactivate' command in Junos allows an administrator to temporarily disable a set of configuration statements without removing them from the configuration. When a statement is deactivated, it is prefixed with 'inactive:' in the configuration hierarchy, and the commit operation ignores it. This is ideal for testing changes, as the statements can be easily re-enabled using the 'activate' command.

Answer

delete the statements and later re-add from a backup

Answer

comment out the lines using #

Answer

set the configuration to a different group and remove apply-groups