User Interfaces

You are managing a Juniper EX4300 switch that serves as a Layer 3 access switch for a campus network. The switch has multiple VLANs configured with IRB interfaces. Users in VLAN 10 report that they cannot reach the default gateway (IRB.10) even though other VLANs are working fine. You check the configuration and see that interface irb.10 is configured with an IP address. You also verify that the VLAN is associated with the correct access ports. However, when you ping the IRB.10 address from the switch itself, it fails. You suspect that the issue might be that the IRB interface is not 'up'. Which command would you use to quickly verify the operational status of the IRB interface?

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

Which TWO commands can be used to view the current active configuration on a Junos device? (Choose two.)

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

A technician is troubleshooting a routing issue and needs to see real-time updates of BGP prefixes being received. Which command should be used?

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

Refer to the exhibit. An administrator needs to ensure that all emergency (emerg) messages are logged to the console. Based on the configuration shown, which statement is correct?

An engineer wants to apply a candidate configuration and automatically revert to the previous configuration after 10 minutes if the commit is not confirmed. Which command should be used?

A user wants to ensure that a configuration change is applied across both Routing Engines in a dual-RE system. Which command must be used?

A network engineer is in configuration mode and wants to see the configuration in a format that can be directly pasted into another router to reproduce the configuration. Which output modifier should they use?

Refer to the exhibit. What does this command accomplish?

An administrator wants to navigate to the configuration mode to make changes to the device. Which command should be used?

An administrator wants to view the current operational status of interface ge-0/0/1 on a Junos device. Which command displays this information?

An administrator is in configuration mode and wants to see only the interfaces configuration block while editing. Which command will display just that section?

A technician needs to display the contents of a configuration file stored on the device's hard disk. Which operational mode command should they use?

A network administrator has made several configuration changes and now wants to revert all uncommitted changes back to the last committed configuration. Which command should they use?

A network administrator is trying to configure a firewall filter on a Juniper device. They enter configuration mode and type 'set firewall family inet filter BLOCK-ICMP term 1 from protocol icmp'. They then type 'set firewall family inet filter BLOCK-ICMP term 1 then reject'. After committing, they notice that ICMP traffic is not being blocked. They run 'show configuration firewall' and see the filter is present. They run 'show firewall filter BLOCK-ICMP' to see the counters and notice the packet count is zero. What is the most likely reason?

Refer to the exhibit. An administrator sees the following configuration output. What is the purpose of the 'description' statement in this context?

Refer to the exhibit. The interface ge-0/0/0 is configured as shown, but the interface is operationally down. Which command would provide the most detailed information about the interface status and errors?

A junior engineer accidentally enters 'set interfaces ge-0/0/0 unit 0 family inet address 192.0.2.1/24' in operational mode. What will happen?

Which TWO statements are true about the 'commit confirmed' command? (Choose two.)

A network engineer wants to view the OSPF log entries in real time. They type 'show log messages | match ospf' and get output, but it does not update. What should they do to see real-time updates of OSPF log entries?

An engineer needs to view the current operational state of the device, including system uptime, CPU load, and memory usage. Which two commands would provide this information? (Choose two.)

A network administrator accidentally deleted a vital part of the configuration while in configuration mode. They need to revert to the previous configuration without losing recent changes that are correct. Which action should they take?

A junior admin tries to commit a configuration but receives a 'commit error: syntax error' message. They suspect a missing closing brace. Which CLI command helps identify the exact line with the error?

Refer to the exhibit. What is the purpose of the 'unit 0' statement?

A technician wants to view the system log messages in real time. Which command should they use?

A senior network administrator is logged into a Juniper device in operational mode. They need to make a configuration change to the BGP group 'INTERNAL'. They type 'configure terminal' and receive 'unknown command'. They then type 'configure' and enter configuration mode. They make the needed changes and exit configuration mode using 'exit'. They then try to view the active configuration to verify the changes by typing 'show configuration | match INTERNAL'. They see no output. What is the most likely reason?

Which TWO statements about the Junos CLI are correct?

You are a junior network engineer at a company that uses Juniper MX routers. You are troubleshooting a connectivity issue on a branch router. The branch router has two upstream links to the corporate network: ge-0/0/0 (10.1.1.1/30, connected to core router A) and ge-0/0/1 (10.1.1.5/30, connected to core router B). The branch router runs OSPF and has a default route learned from both upstream routers. The routing table shows two equal-cost default routes via both next hops. However, traffic from the branch to the corporate network is experiencing intermittent high latency and some packet loss. You suspect that asymmetric routing is causing issues because the return traffic is not following the same path. You want to influence the router to prefer one upstream link for all traffic to the corporate network. You have decided to adjust the OSPF metric on the branch router to make the link to core router A more preferred. You are in configuration mode on the branch router. Which single configuration change will accomplish this goal?

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?

After upgrading Junos, a router fails to boot with a file system error. The admin needs to recover the system from the backup partition. Which key should be pressed during boot to access the boot menu?

Refer to the exhibit. An engineer sees that the interface ge-0/0/0 has 'Admin up' and 'Link up'. What does this indicate?

Refer to the exhibit. What does this output indicate?

A network engineer needs to revert to the configuration that was active before the last commit. Which command accomplishes this?

A network engineer needs to view the operational status of all interfaces on a Junos device, including those that are disabled. Which command should be used?

During a maintenance window, an engineer needs to apply a configuration change that reverts automatically if the commit fails or the administrator does not confirm within a set time. Which feature should be used?

Which THREE CLI features are available in Junos OS to assist with command entry?

A junior network engineer is learning JunOS CLI and wants to view the last 10 lines of the system log file. They log into the device and type 'show log messages | last 10'. They receive an error: 'unknown pipe command'. Which pipe command should they use instead?

You are a network engineer for a service provider that recently deployed a Juniper MX router at a new Point of Presence (PoP). The router is used to aggregate customer connections and exchange routes with upstream providers via BGP. After the initial configuration, you notice that the router is not learning any routes from one of the upstream BGP peers. You have verified that the BGP session is established (state Established) and that the peer is sending routes. You suspect that the issue might be related to the firewall filter or routing policy. You want to determine if any inbound routes are being rejected and why. Which command would provide the most direct information about why routes are being rejected?

A junior engineer is troubleshooting a routing issue and wants to see the route table for IPv4 unicast routes. Which command will display this information?

Refer to the exhibit. An engineer notices high error counts on the interface. Based on the output, what is the most likely cause?

Refer to the exhibit. An engineer runs the command shown. What does this output indicate?

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

Which TWO commands can be used to view the current operational state of an interface? (Choose two.)

A network engineer needs to commit a configuration change but wants to ensure the change can be easily reverted if it causes issues. Which approach should the engineer take?

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

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

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

An engineer is editing the candidate configuration on a Junos device and wants to verify the changes she has made so far without leaving configuration mode or committing anything. She also needs to see only the lines she has added or modified relative to the active configuration. Which command accomplishes this?

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

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

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

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

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

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?

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?

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?

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

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

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

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