JN0-106 Junos Configuration Basics Practice Test 6 — 15 Questions

Question 1

An engineer needs to apply a configuration change to the Junos device that must survive a reboot. Which configuration mode command should be used to save the changes?

Accepted Answer

commit. The 'commit' command is the standard way to apply a candidate configuration to the active configuration in Junos. When you issue 'commit', the changes are saved to the /config/juniper.conf.gz file, which is loaded upon reboot, ensuring the configuration survives a restart.

Answer

commit confirmed

Answer

commit synchronize

Answer

commit check

Question 2

A network engineer wants to quickly restore the device to a known good configuration after a failed change. What is the recommended approach?

Accepted Answer

Use the 'rollback rescue' command.. The 'rollback rescue' command restores the device to the rescue configuration, which is a known good configuration saved explicitly for recovery after a failed change. The rescue configuration is stored as a separate file and is not affected by normal commit operations, making it the recommended approach for quick restoration.

Answer

Use the 'request system configuration rescue save' command.

Answer

Use the 'rollback 0' command.

Answer

Use the 'load override terminal' command.

Question 3

Which configuration group feature allows an administrator to apply common configuration settings to multiple interfaces without repeating the configuration?

Accepted Answer

apply-groups. The `apply-groups` statement is the correct feature because it allows an administrator to define a common configuration template within a `groups` hierarchy and then apply that template to multiple interfaces (or other configuration sections) using the `apply-groups` command. This avoids repeating the same configuration statements across individual interfaces, streamlining management and reducing errors.

Answer

groups statement

Answer

interface-range

Answer

apply-path

Question 4

A company has two Juniper routers in a high-availability cluster with dual Routing Engines. The administrator performs a commit on the primary RE. What is the effect of using the 'commit synchronize' command?

Accepted Answer

It commits the configuration on both Routing Engines simultaneously.. The 'commit synchronize' command on Juniper routers with dual Routing Engines ensures that the configuration is committed on both the primary and backup REs simultaneously. This is critical for maintaining configuration consistency in a high-availability cluster, as it prevents a split-brain scenario where the backup RE has a different active configuration than the primary. The command performs a full commit (including validation and activation) on both REs, not just a check.

Answer

It performs a commit check on both REs but does not activate the config.

Answer

It commits the configuration only on the primary RE.

Answer

It commits the configuration only on the backup RE.

Question 5

While in configuration mode, an administrator wants to see the difference between the candidate configuration and the active configuration. Which command accomplishes this?

Accepted Answer

show | compare. The 'show | compare' command, when executed in configuration mode, displays the differences between the candidate configuration and the active (committed) configuration. This pipe filter compares the current candidate configuration against the last committed configuration, highlighting additions, deletions, and changes, which is the exact requirement for seeing the difference.

Answer

show configuration

Answer

run show configuration

Answer

show system commit

Question 6

A Juniper device has multiple candidate configurations loaded. The administrator wants to discard all uncommitted changes and revert to the last committed configuration. Which command should be used?

Accepted Answer

rollback 0. The 'rollback 0' command reverts the candidate configuration to the last committed configuration, discarding all uncommitted changes. In Junos, the rollback command uses a numeric index where 0 always refers to the most recently committed configuration, effectively undoing any uncommitted edits.

Answer

delete configuration

Answer

clear configuration

Answer

load override terminal

Question 7

An engineer wants to revert all uncommitted changes in the candidate configuration and start fresh from the currently active configuration. Which command should be used?

Accepted Answer

rollback 0. The `rollback 0` command reverts all uncommitted changes in the candidate configuration and restores it to match the currently active configuration (the one most recently committed). This is because Junos stores the last 50 committed configurations, with index 0 always representing the active configuration. Using `rollback 0` effectively discards any uncommitted edits and starts fresh from the last committed state.

Answer

commit check

Answer

rollback 1

Answer

load override terminal

Question 8

During a maintenance window, an engineer issues 'commit confirmed 5' but the change causes a connectivity loss. The engineer is unable to reconnect to the device before the timeout expires. What will happen?

Accepted Answer

The device automatically reverts to the previous active configuration.. The 'commit confirmed 5' command activates a candidate configuration and starts a 5-minute rollback timer. If the engineer does not issue a 'commit' or 'commit check' before the timer expires, Junos automatically reverts to the previously active configuration. This ensures the device returns to a known working state without manual intervention, preserving connectivity after the failed change.

Answer

The engineer must manually rollback using the rollback command.

Answer

The change remains committed until the next reboot.

Answer

The device reloads with factory defaults.

Question 9

Which TWO statements about configuration storage in Junos are true?

Accepted Answer

The rescue configuration is stored in /config/rescue.conf.gz.. The rescue configuration is stored as a compressed file at /config/rescue.conf.gz on Junos devices. This configuration is saved using the 'request system configuration rescue save' command and can be loaded with 'rollback rescue' to recover from a configuration that prevents the device from booting properly.

Answer

The rollback configurations are stored in /config/juniper.conf.0.gz, .1.gz, etc.

Answer

The candidate configuration is stored in /config/.

Answer

The factory default configuration is stored in /etc/config/.

Question 10

Which TWO statements about configuration archival in Junos are true?

Accepted Answer

The 'system archival' hierarchy enables automatic backup of configurations.. The 'system archival' hierarchy in Junos is specifically designed to enable automatic backup of configuration files. This feature allows administrators to configure periodic transfers of committed configurations to a remote server, ensuring configuration history is preserved without manual intervention.

Answer

Archival stores the candidate configuration.

Answer

Archival only saves the rescue configuration.

Answer

Archival automatically archives after every commit without any configuration.

Question 11

Refer to the exhibit. What is the most likely cause of the error?

Accepted Answer

The policy-statement 'test' contains a syntax error in the protocol match condition.. The error message in the exhibit indicates a syntax error in the policy-statement 'test' when using the protocol match condition. In Junos, the 'protocol' match condition requires a valid protocol name (e.g., 'bgp', 'ospf', 'static'), and if an invalid or misspelled protocol is specified, the commit check fails with a syntax error. This is a common mistake when configuring policy-options, as the Junos CLI validates the protocol against a predefined list.

Answer

The IP address 1.1.1.1/32 is already in use.

Answer

The candidate configuration has no errors and this is a warning.

Answer

The commit check command requires user confirmation.

Question 12

A network engineer needs to make a change to a Junos device and ensure the change can be reverted if it causes issues. Which feature should be used?

Accepted Answer

commit confirmed. The `commit confirmed` command allows an engineer to commit a configuration change with a timer (default 10 minutes). If the change causes issues and the engineer does not confirm the commit within the timer, the device automatically reverts to the previous active configuration. This provides a safety net to revert changes without manual intervention.

Answer

configure exclusive

Answer

commit check

Answer

rollback 0

Question 13

A technician needs to load a new configuration file that replaces only the specific hierarchy paths present in the file, leaving all other existing configuration unchanged. Which load statement is appropriate?

Accepted Answer

load merge. The 'load merge' command is correct because it merges the contents of the specified configuration file with the current candidate configuration, adding or updating only the hierarchy paths present in the file while preserving all other existing configuration. This matches the requirement to replace only specific hierarchy paths without affecting the rest of the configuration.

Answer

load replace

Answer

load set

Answer

load override

Question 14

In a dual Routing Engine (RE) setup, an engineer commits a configuration change that should be applied to both REs synchronously. What is the correct command to ensure both REs receive the same configuration immediately?

Accepted Answer

commit synchronize. The 'commit synchronize' command commits the configuration on the master Routing Engine and then automatically copies and commits the same configuration to the backup RE, ensuring both REs have identical active configurations immediately. This is the standard Junos method for synchronizing configurations in a dual-RE chassis.

Answer

commit confirmed

Answer

commit check synchronize

Answer

commit and-quit

Question 15

A network engineer needs to restore the factory-default configuration on a Junos device. Which command sequence is correct?

Accepted Answer

load factory-default and then commit. The correct command sequence to restore factory-default configuration on a Junos device is 'load factory-default' followed by 'commit'. The 'load factory-default' command replaces the current candidate configuration with the factory-default configuration, but it does not take effect until a 'commit' is issued. This ensures the device reverts to its original settings without affecting the currently running configuration until explicitly committed.

Answer

set system host-name factory-default

Answer

request system zeroize

Answer

delete configuration and reboot