Junos OS Fundamentals

A junior engineer is troubleshooting connectivity issues and wants to trace the path packets take to a remote destination. Which Junos command should be used?

A network administrator is configuring a new interface and wants to ensure that the interface is enabled and can pass traffic. Which configuration element is required?

Based on the exhibit, what is the most likely impact on the router?

You are a network administrator for a large enterprise. You have a Juniper SRX firewall that is used as the primary internet gateway. Users are reporting that they are unable to access certain external websites. You check the device and find that the security policies appear correct, and the routing is in place. You suspect that the issue might be related to the DNS resolution. You want to verify that the device can resolve DNS names and that the DNS server configuration is correct. Which command should you use to test DNS resolution from the Juniper device?

Which THREE of the following statements are true regarding Junos OS commit operations?

You are administering a Juniper MX240 router that provides connectivity to multiple customer sites. The router uses BGP to exchange routes with two upstream ISPs. Recently, you applied a new firewall filter to the loopback interface to restrict management access. After committing the configuration, you can no longer establish SSH sessions to the router from the management network. You are currently connected via console. The loopback filter is still applied. You suspect the filter is blocking SSH traffic from the management network. What should you do to restore SSH access without losing the other filter rules?

Which THREE statements are true about commit operations in Junos OS?

Order the steps to configure a user account with a password in Junos.

Which Junos CLI mode allows a user to view the configuration and execute operational commands, but not make configuration changes?

A network administrator makes several changes to the configuration but decides to discard all uncommitted changes and start fresh. Which command should be used to revert the candidate configuration back to the current active configuration?

A Juniper device fails to boot and stops at the 'loader>' prompt. What is the most likely cause of this issue?

A technician notices that the /var partition on a Junos device is 95% full. Which action will immediately free up disk space without affecting device operation?

A network operator needs to backup the current configuration to a file on the local flash. Which command accomplishes this?

Refer to the exhibit. The network administrator made a change that caused connectivity loss. They need to revert to the configuration before the most recent commit. Which command would accomplish this?

What is the primary function of the fxp0 interface on a Juniper device?

An engineer wants to roll back to the previous configuration. Which command should be used?

A Junos device has multiple configuration files saved. Which command shows the available rollback configurations?

What happens when a user issues the 'request system reboot' command without any options?

Which TWO statements are true about the Junos file system? (Choose two.)

Which TWO statements describe correct methods to enter configuration mode? (Choose two.)

Refer to the exhibit. An operator tries to ping 192.168.1.2 from this router and fails. The router can ping itself (192.168.1.1). What is the most likely cause?

Refer to the exhibit. A security analyst sees repeated login failures from 10.0.0.2 for user1. Which Junos feature can be used to automatically block further login attempts from that IP?

Refer to the exhibit. An administrator wants to see authentication-related logs like SSH logins. In the current configuration, which log file contains this information?

A company wants to implement best practice for password recovery on Juniper devices to avoid service disruption. Which of the following is the recommended method?

An administrator notices that after committing a configuration change on a Juniper MX router, the device loses connectivity to the management network. The management interface is part of a dedicated management routing instance. Which of the following is the most likely cause?

A network engineer needs to upgrade Junos on an MX router with dual Routing Engines (RE0 and RE1). What is the recommended procedure to minimize downtime?

A junior administrator wants to view the current active configuration on a Juniper device. Which operational mode command should be used?

During a network traffic storm, a Juniper EX switch's CPU utilization spikes to 100%. Which command would best help identify the cause?

A company has multiple Juniper devices and wants to standardize configuration snapshots for backup and audit purposes. What is the best practice?

What is the purpose of the 'commit confirmed' command in Junos OS?

You are a network engineer at a company that operates a pair of Juniper SRX firewalls in an active/passive cluster (Chassis Cluster). The cluster has been running Junos 15.1X49-D100 for over a year. Management has mandated an upgrade to a newer version to address security vulnerabilities. You follow the recommended upgrade procedure and successfully upgrade the primary node (node0) first, then failover to make node0 the backup, and upgrade the new primary (node1). After the upgrade, both nodes have the same version and appear to be in the cluster, but you notice that the backup node (node0) is stuck in 'ineligible' state and does not synchronize configuration changes. What is the most likely cause?

You are a network administrator for a service provider that uses Juniper MX series routers to provide MPLS VPN services to customers. Management has requested that you implement a secure out-of-band management (OOBM) solution for all MX routers to ensure that management traffic is isolated from the production network, reducing the risk of unauthorized access and management plane attacks. You are tasked with designing the OOBM solution using a dedicated management interface (me0) and a separate management routing instance. Which of the following best practices should you follow?

Your data center uses Juniper QFX5110 switches as leaf nodes in a Virtual Chassis Fabric (VCF) topology with QFX5100 as spine nodes. You are adding a new QFX5110 leaf node to the fabric. The new switch is physically connected to all spine nodes as per the cabling guidelines. However, after powering on the new switch, it does not automatically join the fabric. The existing fabric shows the new switch's member ID as 8, but it remains in 'standalone' state. The VCF has been operational for several months without issues. You check the configuration on the existing VC and notice that the 'virtual-chassis' configuration does not include the new member. What is the most likely reason the new switch does not join?

A junior network administrator is setting up a Juniper MX router for the first time. After powering on the device, the administrator notices that the LED on the front panel blinks amber and the device does not complete the boot process. The console displays messages reporting file system errors. The administrator has no previous configuration changes and the device was shipped with factory defaults. Which action should the administrator take to resolve the boot issue?

A network engineer made several configuration changes on a Juniper QFX switch to implement new VLANs. After committing the changes, the engineer realized that the new configuration caused a critical loss of connectivity to the management network. The engineer needs to revert to the previous configuration that was working. The switch is still accessible via the console port, and the engineer has privilege level access. The previous configuration was committed two commits ago, and the current active configuration is the problematic one. Which action should the engineer take to restore the previous working configuration?