Courseiva

CCNA Junos User Interfaces Questions

22 of 97 questions · Page 2/2 · Junos User Interfaces topic · Answers revealed

Practice these questionsExam hubAll questions
76
MCQmedium

You are a network engineer for a company that has just deployed a Juniper SRX firewall in a branch office. The device has multiple interfaces: ge-0/0/0 connected to the internet, ge-0/0/1 connected to the internal LAN (192.168.1.0/24), and ge-0/0/2 connected to a DMZ (10.0.0.0/24). After initial configuration, you attempt to ping from the SRX to a server on the internet (8.8.8.8) but receive no response. You also notice that internal users can access the internet. You have verified the routing table shows a default route via ge-0/0/0. The security policies appear correct. You suspect the issue is related to interface configuration. What is the most likely cause and the correct course of action?

A.The security policy from the trust zone to the untrust zone is blocking traffic; you should create a policy allowing all traffic from the SRX itself.
B.The interface ge-0/0/0 has an incorrect MAC address; you should clear the ARP cache.
C.The interface ge-0/0/0 is missing the 'host-inbound-traffic' configuration under its security zone; you should add the appropriate system services under the zone.
D.The default route is missing or incorrect; you should add a default route via the internet gateway IP.
AnswerC

This is the most likely cause because the device cannot initiate traffic without explicit host-inbound traffic settings.

Why this answer

The SRX can ping internal hosts but not the internet because the interface ge-0/0/0 is in the untrust zone, which by default blocks all inbound traffic, including pings originated from the device itself. The 'host-inbound-traffic' configuration under the security zone allows system services such as ping, SSH, and SNMP to be received on that interface. Without it, even though the routing table and security policies are correct, the SRX will drop its own outbound ICMP echo requests before they can be sent, or drop the replies if they are treated as inbound traffic.

Exam trap

The trap here is that candidates confuse transit security policies (which control traffic passing through the device) with host-inbound traffic controls (which manage traffic destined to the device itself), leading them to incorrectly modify security policies instead of enabling system services under the zone.

How to eliminate wrong answers

Option A is wrong because the security policy from trust to untrust controls traffic passing through the SRX, not traffic originated from the SRX itself; device-originated traffic is governed by the 'host-inbound-traffic' settings, not security policies. Option B is wrong because an incorrect MAC address would cause a failure to resolve the next-hop MAC, which would prevent all traffic (including internal users) from reaching the internet, but internal users can access the internet, so ARP is working. Option D is wrong because the routing table already shows a default route via ge-0/0/0, and internal users can access the internet, confirming the default route is correct.

Practice this question →
77
MCQhard

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

A.Manually configure each interface individually.
B.Use wildcard set with regex to match all interfaces except fxp0.
C.Create a configuration group that includes all interfaces and use apply-groups-except to exclude fxp0.
D.Use the 'set interfaces fxp0 disable' command and then apply changes to all interfaces.
AnswerC

apply-groups-except allows selective exclusion from a group.

Why this answer

Option C is correct because 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.

Exam trap

The trap here is that candidates may think Junos supports regex-based exclusion in wildcard set commands (like Cisco IOS does with 'interface range' and 'exclude'), but Junos wildcard set only supports simple prefix/suffix matching and cannot exclude specific interfaces, making configuration groups with apply-groups-except the correct and intended method.

How to eliminate wrong answers

Option A is wrong because manually configuring each interface individually is inefficient, error-prone, and does not scale for large numbers of interfaces. Option B is wrong because wildcard set with regex to match all interfaces except fxp0 is not supported in Junos; the wildcard set command only allows simple patterns with asterisks and cannot perform negative matching or regex exclusions. Option D is wrong because disabling the management interface (fxp0) would break out-of-band management access, and the approach does not actually exclude fxp0 from the configuration changes—it simply disables it, which is not the goal.

Practice this question →
78
Multi-Selecthard

A junior administrator is learning to navigate the Junos CLI. Which three statements about CLI modes are correct? (Choose three.)

Select 3 answers
A.Operational mode is indicated by a > prompt.
B.Configuration mode is entered using the 'configure' command.
C.The 'commit' command is available in both operational and configuration modes.
D.You can switch from configuration mode to operational mode using the 'exit configuration' command.
E.You can execute operational mode commands from configuration mode by prefixing with 'run'.
AnswersA, B, E

Correct; the prompt ends with '>' in operational mode.

Why this answer

Option A is correct because the Junos CLI uses the '>' character to indicate operational mode, which is the default mode for monitoring and troubleshooting the device. In this mode, you can execute commands like 'show' and 'ping' but cannot make configuration changes.

Exam trap

The trap here is that candidates familiar with Cisco IOS may assume the 'commit' command is available in both modes, but in Junos it is strictly a configuration-mode command, and the 'exit configuration' command is a common misremembering of the correct syntax 'exit' or 'exit configuration-mode'.

Practice this question →
79
MCQhard

During troubleshooting, an engineer needs to view real-time logging messages on a Junos device. Which command should be used?

A.file show /var/log/messages
B.monitor start messages
C.show log messages
D.traceoptions
AnswerB

Displays real-time log messages.

Why this answer

The 'monitor start messages' command enables real-time, tail-like display of the /var/log/messages log file on a Junos device, allowing the engineer to view new log entries as they are generated. This is the correct command for live troubleshooting because it continuously updates the terminal with incoming syslog messages, unlike static file viewing commands.

Exam trap

The trap here is that candidates often confuse 'show log messages' (a static snapshot) with 'monitor start messages' (a live streaming view), because both involve the 'messages' log file, but only the latter provides real-time output.

How to eliminate wrong answers

Option A is wrong because 'file show /var/log/messages' displays the entire contents of the log file at once, not in real-time, and is not suitable for monitoring live events. Option C is wrong because 'show log messages' displays the current contents of the messages log file but does not provide a live, streaming view; it shows a snapshot. Option D is wrong because 'traceoptions' is a configuration statement used to enable debug logging for specific protocols or features, not a command to view real-time log output.

Practice this question →
80
MCQmedium

An administrator needs to see which interfaces are configured and their current operational status in a concise format. Which command provides this information?

A.show interfaces
B.show configuration interfaces
C.show interfaces terse
D.show interfaces descriptions
AnswerC

Correctly provides a one-line summary per interface including admin and operational status.

Why this answer

The 'show interfaces terse' command displays a concise, table-like output listing all interfaces (including logical units) along with their administrative status (up/down) and operational status (up/down). This is the most efficient way to see both configured interfaces and their current state in a compact format, as required by the question.

Exam trap

The trap here is that candidates familiar with Cisco IOS often expect 'show interfaces' to be the concise status command, but in Junos, 'show interfaces terse' is the equivalent of 'show ip interface brief' — a distinction that catches those who assume cross-platform command similarity.

How to eliminate wrong answers

Option A is wrong because 'show interfaces' provides detailed per-interface statistics and configuration, which is verbose and not concise. Option B is wrong because 'show configuration interfaces' displays the configured interface hierarchy from the candidate or active configuration, not the current operational status. Option D is wrong because 'show interfaces descriptions' shows only the description field for interfaces, not their operational status.

Practice this question →
81
Multi-Selecthard

Which THREE are valid methods to exit configuration mode in Junos? (Choose three.)

Select 3 answers
A.exit configuration-mode
B.commit and-quit
C.commit check
D.exit (at the top of the hierarchy)
E.quit
AnswersA, B, D

Exits configuration mode.

Why this answer

Option A is correct because 'exit configuration-mode' is a valid operational mode command that explicitly exits from configuration mode back to operational mode. This command is used when you are at the top of the configuration hierarchy and want to leave the configuration CLI session.

Exam trap

The trap here is that Cisco engineers often expect 'quit' to work (as it does in IOS), but Junos does not recognize 'quit' as a valid command, and 'commit check' is a validation command that does not exit configuration mode.

Practice this question →
82
Multi-Selecteasy

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

Select 2 answers
A.edit
B.set
C.configure
D.config
E.terminal
AnswersA, C

Typing 'edit' at the operational prompt enters configuration mode.

Why this answer

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.

Exam trap

The trap here is that Cisco engineers often expect 'config terminal' or 'configure terminal' as the way to enter configuration mode, but Junos uses 'configure' or 'edit' without the 'terminal' keyword, and 'config' alone is not a valid command.

Practice this question →
83
MCQhard

Refer to the exhibit. An engineer runs the command but sees no output. What is the most likely reason?

A.The pipe (|) is not supported with 'display set'.
B.The interface ge-0/0/0 is not configured.
C.The interface name is misspelled.
D.The command syntax is incorrect.
AnswerB

Most likely the interface does not exist in config.

Why this answer

The command 'show configuration | display set' outputs the configuration in a set-based format. If there is no output, it means the configuration is empty or the specified interface does not exist. In this case, the interface ge-0/0/0 is not configured, so the filter 'display set' returns no lines for that interface.

Option B is correct because an unconfigured interface yields no configuration output.

Exam trap

The trap here is that candidates may assume the pipe command is unsupported or that the syntax is wrong, when in fact the absence of output is due to the interface not being configured in the candidate or active configuration.

How to eliminate wrong answers

Option A is wrong because the pipe (|) is fully supported with 'display set' in Junos; it is a standard filter to convert configuration to set commands. Option C is wrong because the interface name 'ge-0/0/0' is correctly spelled (gigabit-ethernet 0/0/0) and is a valid Junos interface designation. Option D is wrong because the command syntax 'show configuration | display set' is correct and commonly used to display the active configuration in a compact, set-based format.

Practice this question →
84
MCQhard

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

A.view
B.control
C.system
D.network
AnswerD

network permission allows diagnostic tools like ping and traceroute.

Why this answer

The correct answer is D, 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.

Exam trap

The trap here is that candidates often assume 'view' or 'control' permissions are sufficient for basic troubleshooting commands, but Junos requires the specific 'network' permission bit for any command that sends or receives network traffic.

How to eliminate wrong answers

Option A is wrong because 'view' permission allows read-only access to configuration and operational data, but does not permit execution of diagnostic commands like ping. Option B is wrong because 'control' permission allows modifying the configuration and managing system operations, but does not grant access to network diagnostic commands. Option C is wrong because 'system' permission controls system-level commands such as halt, reboot, and file system operations, not network diagnostic tools like ping.

Practice this question →
85
MCQeasy

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

A.rollback 0
B.rollback 2
C.rollback 1
D.rollback 3
AnswerB

rollback 2 reverts to the configuration committed two commits ago.

Why this answer

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.

Exam trap

The trap here is confusing the rollback number with the number of commits to revert, where candidates might mistakenly think rollback 1 means one commit ago (which is correct) but then incorrectly apply that logic to two commits ago by choosing rollback 1 instead of rollback 2.

How to eliminate wrong answers

Option A is wrong because rollback 0 refers to the most recent committed configuration, not two commits ago. Option C is wrong because rollback 1 refers to the configuration committed one commit ago, not two. Option D is wrong because rollback 3 refers to the configuration committed three commits ago, which is further back than needed.

Practice this question →
86
MCQeasy

An administrator wants to see the differences between the candidate configuration and the active configuration. Which command should be used?

A.show | display set
B.run show configuration
C.show | compare
D.show configuration
AnswerC

Shows differences between candidate and active.

Why this answer

The 'show | compare' command displays the differences between the candidate configuration and the active (committed) configuration. This is the standard Junos method for reviewing uncommitted changes before committing them, as it outputs a diff-style output showing lines added, deleted, or modified.

Exam trap

The trap here is that candidates often confuse 'show | compare' with 'show configuration' or 'show | display set', thinking they all show differences, but only 'show | compare' provides the explicit diff output between candidate and active configurations.

How to eliminate wrong answers

Option A is wrong because 'show | display set' reformats the output of the 'show' command into 'set' commands, but does not compare configurations. Option B is wrong because 'run show configuration' is used to display the active configuration on the RE (Routing Engine) from the shell, not to compare candidate and active configurations. Option D is wrong because 'show configuration' displays the entire active configuration, not the differences between candidate and active.

Practice this question →
87
MCQeasy

An engineer needs to view the current active configuration of a Junos device without making any changes. Which CLI mode should they use?

A.Operational mode
B.Privileged mode
C.Configuration mode
D.Exclusive configuration mode
AnswerA

Operational mode provides read-only access to configuration and operational commands.

Why this answer

Operational mode is the default CLI mode in Junos, used for monitoring, troubleshooting, and viewing the current active configuration without making any changes. Commands in this mode are read-only and do not modify the device's configuration. The active configuration is the one currently running on the device, and it can be viewed using commands like 'show configuration' in operational mode.

Exam trap

The trap here is that candidates familiar with Cisco IOS may confuse 'Privileged mode' (which allows viewing and some changes) with Junos operational mode, but Junos strictly separates read-only (operational) and read-write (configuration) modes.

How to eliminate wrong answers

Option B is wrong because 'Privileged mode' is a Cisco IOS term, not a Junos CLI mode; Junos uses operational mode for read-only access and configuration mode for changes. Option C is wrong because Configuration mode is used to modify the candidate configuration, not just view the active configuration; entering this mode allows changes to be made. Option D is wrong because Exclusive configuration mode is a variant of configuration mode that locks the configuration database to prevent other users from making changes, but it still allows modifications and is not for read-only viewing.

Practice this question →
88
MCQeasy

A user wants to see all available commands starting with 'show'. Which key should they press after typing 'show'?

A.Space
B.?
C.Tab
D.Ctrl-P
AnswerB

Displays context-sensitive help, listing all commands starting with 'show'.

Why this answer

In the Junos CLI, pressing the '?' key after typing a partial command like 'show' displays a list of all available commands or options that start with that string. This is the standard context-sensitive help feature in Junos, which is distinct from other CLI behaviors.

Exam trap

The trap here is that candidates familiar with Cisco IOS may expect the Tab key to list completions, but in Junos, Tab only auto-completes a unique command, while '?' is used to list all available options.

How to eliminate wrong answers

Option A is wrong because pressing the Space bar after 'show' would execute the command if it is complete, or cause an error if incomplete; it does not display available commands. Option C is wrong because the Tab key in Junos CLI performs command completion (auto-fills the command if unique), not listing all available options. Option D is wrong because Ctrl-P is a readline shortcut that recalls the previous command from the history buffer, not related to showing available commands.

Practice this question →
89
MCQeasy

A junior engineer uses 'set system host-name R1' in configuration mode and exits without committing. After a reboot, the hostname reverts to the original. What step did the engineer miss?

A.They must use 'run set system host-name' instead.
B.They must save the configuration to a file.
C.They must reboot after setting the hostname.
D.They must commit the configuration with 'commit'.
AnswerD

Commit activates the candidate configuration, making it persist across reboots.

Why this answer

In Junos OS, configuration changes made in configuration mode are stored in a candidate configuration and do not take effect until explicitly committed using the 'commit' command. Rebooting without committing discards all uncommitted changes, causing the hostname to revert to its original value. Option D is correct because the engineer must issue 'commit' to activate the new hostname permanently.

Exam trap

The trap here is that candidates familiar with Cisco IOS may assume changes take effect immediately in configuration mode, but Junos requires an explicit 'commit' to activate changes, and rebooting does not save uncommitted changes.

How to eliminate wrong answers

Option A is wrong because 'run set system host-name' is not a valid command; 'run' executes operational-mode commands, while 'set system host-name' is a configuration-mode command. Option B is wrong because saving the configuration to a file (e.g., with 'save') is not required for activation; the candidate configuration is automatically stored in memory and only needs to be committed to become the active configuration. Option C is wrong because rebooting is unnecessary and does not commit changes; in fact, rebooting without committing discards uncommitted changes, which is the opposite of the desired outcome.

Practice this question →
90
MCQhard

Tom is a junior network engineer who recently joined a service provider. He is tasked with configuring a new BGP session on an MX240 router to peer with a customer. He accesses the router via SSH and enters configuration mode using the `configure` command. He then navigates to `edit protocols bgp` and begins configuring. He sets the local AS number, adds a group named 'CUSTOMER-A', and specifies the peer IP address 192.0.2.2. After completing the configuration, he attempts to commit by typing `commit`. The system returns a syntax error and indicates that the configuration is invalid. Tom is unsure what went wrong and wants to identify the error before making any changes. What should Tom do next?

A.Issue the `commit check` command to validate the candidate configuration syntax.
B.Issue the `show | compare` command to see the differences from the previous committed configuration.
C.Issue the `run show configuration protocols bgp` command to display the current active configuration.
D.Issue the `edit protocols bgp` command again to re-enter the hierarchy and review the settings.
AnswerA

This command checks the syntax of the candidate configuration and reports errors.

Why this answer

Option B is correct because `commit check` validates the candidate configuration syntax without committing, and will point out the specific error. Option A only shows changes but does not check syntax. Option C displays the active (committed) configuration, not the candidate.

Option D simply re-enters the hierarchy, which does not help identify the error.

Practice this question →
91
MCQhard

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?

A.rollback 0 and commit check
B.load override rollback 1 and commit
C.rollback 0 and then commit
D.request system configuration rescue save and then load rescue
AnswerB

This replaces the candidate with rollback 1, then commits it.

Why this answer

Option B is correct because '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.

Exam trap

The trap here is confusing 'rollback 0' (the current active configuration) with 'rollback 1' (the previous configuration), leading candidates to choose options that simply re-commit the current state instead of reverting to the prior one.

How to eliminate wrong answers

Option A is wrong because 'rollback 0' refers to the current active configuration, and 'commit check' only validates syntax without applying changes; this does not revert to a previous state. Option C is wrong because 'rollback 0' followed by 'commit' would re-commit the current configuration, which still contains the problematic apply-group, so no reversion occurs. Option D is wrong because 'request system configuration rescue save' saves the current configuration as a rescue configuration, and 'load rescue' loads that same current configuration; this does not revert to rollback 1 and may overwrite any existing rescue configuration.

Practice this question →
92
MCQmedium

You are a network engineer responsible for a Juniper MX240 router in a data center. The router is running Junos 18.2R1 and you need to upgrade it to 19.1R2 to fix a critical security vulnerability. You establish an SSH session to the router and enter configuration mode to prepare the upgrade. While in configuration mode, you notice that the candidate configuration contains several uncommitted changes from a previous engineer that attempted to modify BGP settings but introduced a syntax error. The candidate configuration fails any commit operation due to this error. The currently active configuration is stable and the router is handling production traffic. The upgrade process requires you to change the boot media and specify the new image. Which action should you take to clear the candidate configuration and proceed with the upgrade?

A.Reboot the router to clear the candidate configuration and then start the upgrade.
B.Execute the 'rollback 0' command to discard the candidate and replace it with the active configuration, then proceed with the upgrade commands.
C.Run the 'load override terminal' command and paste the active configuration from memory, then commit and upgrade.
D.Use the 'commit force' command to override the syntax error and commit the candidate, then perform the upgrade.
AnswerB

This clears the problematic candidate while preserving the active config.

Why this answer

Option B is correct because the 'rollback 0' command discards all uncommitted changes in the candidate configuration and replaces it with the active, committed configuration. This clears the syntax error without affecting the running router, allowing you to proceed with the upgrade commands (e.g., 'request system software add') without a reboot or forced commit.

Exam trap

The trap here is that candidates may think a reboot is needed to clear uncommitted changes (Option A) or that 'commit force' can bypass syntax errors (Option D), when in fact Junos provides a dedicated 'rollback' command to safely discard the candidate configuration without impacting the active state.

How to eliminate wrong answers

Option A is wrong because rebooting the router would disrupt production traffic and is unnecessary; the candidate configuration is not stored in active memory that requires a reboot to clear. Option C is wrong because 'load override terminal' is used to load a configuration from a terminal session, not to discard the candidate; it would require manually pasting the active config, which is error-prone and redundant when 'rollback 0' exists. Option D is wrong because 'commit force' does not override syntax errors; it only bypasses certain validation warnings (e.g., missing root password), and a syntax error in the candidate will still cause the commit to fail.

Practice this question →
93
MCQmedium

An administrator is troubleshooting an interface and wants to see real-time packet statistics. Which command should they use?

A.traceoptions
B.show interfaces statistics
C.show interfaces extensive
D.monitor interface
AnswerD

monitor interface displays real-time interface statistics.

Why this answer

The 'monitor interface' command in Junos provides real-time, continuously updated packet statistics for a specified interface, making it the correct choice for live troubleshooting. Unlike static commands, it refreshes statistics every second until interrupted, allowing the administrator to observe traffic patterns as they occur.

Exam trap

The trap here is that candidates often confuse 'show interfaces statistics' (a static snapshot) with real-time monitoring, failing to recognize that only 'monitor interface' provides live, continuously updated data.

How to eliminate wrong answers

Option A is wrong because 'traceoptions' is used for debugging control-plane protocols (e.g., OSPF, BGP) by logging events to a file, not for viewing real-time interface packet statistics. Option B is wrong because 'show interfaces statistics' displays a static snapshot of cumulative packet counts at the moment the command is issued, not real-time updates. Option C is wrong because 'show interfaces extensive' provides detailed static output including errors and queue information, but it does not refresh automatically or show live statistics.

Practice this question →
94
Multi-Selecteasy

Which THREE modes can be used to enter configuration mode in Junos? (Choose three.)

Select 3 answers
A.configure static
B.configure private
C.configure shared
D.configure dynamic
E.configure exclusive
AnswersB, C, E

Creates a private copy of the candidate configuration.

Why this answer

Option B is correct because 'configure private' creates a private configuration session that isolates candidate changes from other users, allowing multiple users to stage changes simultaneously without interference. This mode is one of the three standard configuration modes in Junos, alongside exclusive and shared.

Exam trap

The trap here is that candidates may confuse Junos configuration modes with Cisco IOS configuration modes (like 'configure terminal' or 'configure memory'), leading them to select non-existent options like 'configure static' or 'configure dynamic'.

Practice this question →
95
Multi-Selecthard

Which TWO statements correctly describe the behavior of the 'commit confirmed' command in Junos?

Select 2 answers
A.The confirmation timeout can be modified by specifying a number of minutes.
B.The default confirmation timeout is 5 minutes.
C.It requires a reboot to revert to the previous configuration.
D.It activates the configuration and schedules an automatic rollback unless confirmed.
E.It stages the configuration in the candidate configuration but does not apply it until confirmed.
AnswersA, D

Correct: The timeout can be set from 1 to 65535 minutes.

Why this answer

Option A is correct because the `commit confirmed` command in Junos accepts an optional numeric argument (in minutes) to override the default confirmation timeout. For example, `commit confirmed 10` sets a 10-minute window during which the administrator must issue a `commit` to make the changes permanent; otherwise, the system automatically rolls back to the previous active configuration.

Exam trap

The trap here is that candidates often confuse the default timeout with Cisco's 5-minute default for `configure confirm` or mistakenly think the configuration is only staged and not applied until confirmed, whereas Junos immediately activates it and schedules an automatic rollback.

Practice this question →
96
Multi-Selectmedium

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

Select 3 answers
A.no-more
B.count
C.display set
D.match
E.except
AnswersB, D, E

Counts the number of lines in the output.

Why this answer

Option B is correct because 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.

Exam trap

The trap here is that candidates often confuse pipe modifiers that change display behavior (like 'no-more' or 'display set') with those that actually filter the output content, leading them to select 'no-more' as a filtering modifier when it only controls pagination.

Practice this question →
97
MCQmedium

An engineer is troubleshooting a connectivity issue and wants to see real-time interface traffic statistics. Which command provides continuous updates?

A.show interface statistics
B.monitor interface traffic
C.monitor start messages
D.show interfaces extensive
AnswerB

Continuously updates interface traffic statistics.

Why this answer

The `monitor interface traffic` command in Junos OS provides a real-time, continuously updating display of interface traffic statistics, making it the correct choice for live monitoring. Unlike static commands that show a single snapshot, this command refreshes the output at a default interval (typically 1 second) until the user interrupts it with Ctrl+C.

Exam trap

The trap here is that candidates often confuse `monitor interface traffic` with `show interface statistics`, assuming both provide live updates, but only the `monitor` command offers continuous real-time output in Junos OS.

How to eliminate wrong answers

Option A is wrong because `show interface statistics` displays a static snapshot of interface counters at the moment the command is executed, not continuous updates. Option C is wrong because `monitor start messages` is used to monitor system log messages in real time, not interface traffic statistics. Option D is wrong because `show interfaces extensive` provides a detailed static output of interface configuration and statistics, but does not offer continuous, live updates.

Practice this question →
← PreviousPage 2 of 2 · 97 questions total

Ready to test yourself?

Try a timed practice session using only Junos User Interfaces questions.

Start 20-question session