Juniper JN0-105 Online Practice Questions and Exam Preparation

Juniper JN0-105 Online Questions & Answers

• Question 1:

  You want to redeploy a Junos device by clearing the existing configuration and resetting it to factory defaults.

  In this scenario, which command would help to accomplish this task?

  A. show system storage
  B. request systemstorage cleanup
  C. request systemstorage cleanup dry-run
  D. request systemzeroize media
  D. request systemzeroize media

  ---

  explanation:

  Explanation

  The request system zeroize media command on a Junos device securely erases all data, including configuration and log files, and resets the device to its factory default settings. This command is used when redeploying a device to ensure no residual data remains from its previous deployment. It's a comprehensive and secure way to clear all configurations and data, making the device as if it were new. The other commands listed do not perform a full reset to factory defaults; for example, show system storage displays storage information, and request system storage cleanup offers to delete unnecessary files without resetting the device to factory settings.

• Question 2:

  Which protocol would you configure to synchronize the time and date on a Junos device?

  A. SNMP
  B. RIP
  C. NTP
  D. NMP
  C. NTP

  ---

  explanation:

  Explanation

  The Network Time Protocol (NTP) is designed to synchronize the clocks of computers over a network. Configuring NTP on a Junos device ensures that its clock is set accurately, which is crucial for logging, troubleshooting, and maintaining the integrity of time-sensitive operations and security protocols. NTP allows devices to use a hierarchy of time sources, from primary servers synchronized to a reference clock (such as an atomic clock or GPS time) to secondary servers that distribute the time to other devices on the network.

• Question 3:

  Exhibit

  policy-options { policy-statement Load-Balance-Policy { term Load-Balance { then { load- balance per-flow; accept;

  }

  }

  }

  }

  routing-options {

  router-id 192.168.100.11; autonomous-system 65201; forwarding-table {

  export Load-Balance-Policy;

  Referring to the exhibit, which two statements are correct? (Choose two.)

  A. The policy enables equal cost load balancing in the forwarding table.
  B. The policy must be applied under the protocols hierarchy.
  C. The policy enables per-packet load balancing.
  D. The policy enables flow-based load balancing.
  A. The policy enables equal cost load balancing in the forwarding table.
  D. The policy enables flow-based load balancing.

  ---

  explanation:

  Explanation

  The load-balance per-flow statement in the Junos OS policy-options configuration enables flow-based load balancing in the forwarding table. This means that the traffic is distributed across multiple paths based on flows, where a flow is typically identified by attributes such as source and destination IP addresses, and possibly layer 4 information like TCP/UDP ports. This allows for more granular and efficient utilization of available paths, avoiding overloading a single path. The policy does not enable per-packet load balancing, which would send individual packets of the same flow over different paths, potentially causing out-of-order delivery issues. The policy's placement in the forwarding- table export suggests it's intended to influence forwarding behavior, not just routing protocol decisions, and does not necessarily have to be applied under the protocols hierarchy.

• Question 4:

  Exhibit

  [edit]

  root# set system host-name TEST_DEVICE [edit]

  root# commit

  [edit]

  'system'

  Missing mandatory statement: 'root-authentication' error: commit failed: (missing mandatory statements) [edit] root#

  You are configuring a new device.

  Which action solves the error shown in the exhibit?

  A. configuring a non-root username and password
  B. configuring a password for the root account
  C. loading the factory-default configuration
  D. reinstalling Junos
  B. configuring a password for the root account

  ---

  explanation:

  Explanation

  The error message in the exhibit indicates that the root-authentication statement is missing, which is mandatory for committing the configuration. In Junos OS, it is required to set a password for the root account to commit any configuration changes. This is a security measure to ensure that unauthorized users cannot access the device's configuration mode. To solve the error shown in the exhibit, configuring a password for the root account is necessary. This can be done by using the set system root-authentication plain-text-password command, after which the user will be prompted to enter a new password for the root account.

• Question 5:

  Exhibit

  term limit-icmp { from {

  source-address {

  172.25.11.0/24;

  }

  protocol icmp;

  }

  then {

  count count-icmp; discard;

  }

  }

  Referring to the exhibit, which two actions will occur when a packet matches the firewall filter? (Choose two.)

  A. An ICMP destination unreachable message will be returned.
  B. The packet will be forwarded.
  C. The packet will be discarded.
  D. A counter will be incremented.
  C. The packet will be discarded.
  D. A counter will be incremented.

  ---

  explanation:

  Explanation

  C. The packet will be discarded:

  The discard; action in the filter means that the matching packet will be dropped and will not be forwarded through the firewall.

  D. A counter will be incremented:

  The count count-icmp; action ensures that every packet matching this rule will increment the specified counter (count-icmp). This allows administrators to monitor and track the number of packets matching this rule.

• Question 6:

  A network administrator is attempting to route traffic on a Juniper switch to one of three different VLANs: Prod, Test, and Dev. Each VLAN has been assigned a numerical value. In this scenario, what are these numerical values called?

  A. defaults
  B. interfaces
  C. names
  D. tags
  D. tags

  ---

  explanation:

  Explanation

  In the context of VLANs (Virtual Local Area Networks) on a Juniper switch, the numerical values assigned to each VLAN, such as those for Prod, Test, and Dev, are known as VLAN tags. These tags are part of the 802.1Q VLAN standard, which allows multiple VLANs to coexist on a single physical network. Each tag uniquely identifies the VLAN to which a frame belongs, enabling the switch to segregate and manage traffic based on VLAN membership. This tagging mechanism allows for efficient traffic separation and management, ensuring that devices within one VLAN do not receive traffic intended for another, thus maintaining network security and efficiency.

• Question 7:

  Which two functions are performed by the PFE? (Choose two.)

  A. It forwards transit traffic.
  B. It maintains the routing table.
  C. It selects active routes.
  D. It implements firewall filters.
  A. It forwards transit traffic.
  D. It implements firewall filters.

  ---

  explanation:

  Explanation

  The Packet Forwarding Engine (PFE) in Junos OS performs several key functions, including implementing firewall filters and forwarding transit traffic. The PFE applies firewall filter rules to incoming and outgoing traffic and is responsible for the high-speed forwarding of packets based on the information in the forwarding table.

• Question 8:

  What are two functions of the Routing Engine? (Choose two.)

  A. It runs the Junos operating system.
  B. It processes transit traffic.
  C. It evaluates firewall filters for transit traffic.
  D. It processes all management traffic.
  A. It runs the Junos operating system.
  D. It processes all management traffic.

  ---

  explanation:

  Explanation

  The Routing Engine (RE) in Junos OS has several critical functions, including processing all management traffic and running the Junos operating system. The RE handles system management tasks, user interfaces, system services, and routing protocol processes. It does not directly process transit traffic or evaluate firewall filters for transit traffic, as these tasks are handled by the Packet Forwarding Engine (PFE).

• Question 9:

  Which two fields are you required to enter when you create a new user account? (Choose two.)

  A. login class
  B. username
  C. user ID
  D. full name
  A. login class
  B. username

  ---

  explanation:

  Explanation

  In Junos OS, when creating a new user account, the minimum required fields are the username and the login class. The username is the identifier for the account, while the login class specifies the level of access or permissions the user has on the device. Login classes allow for the differentiation between various roles, such as read-only access or full administrative rights. Other information, such as full name or user ID, is optional and not strictly necessary for the creation of a functional user account.

• Question 10:

  Which two common routing policy actions affect the flow of policy evaluation? (Choose two.)

  A. next term
  B. next hop
  C. next policy
  D. community
  A. next term
  C. next policy

  ---

  explanation:

  Explanation

  In Junos OS routing policy evaluation, "next policy" and "next term" are common actions that affect the flow of policy evaluation. "Next policy" directs the evaluation to the next policy in the sequence, whereas "next term" moves the evaluation to the next term within the current policy, allowing for granular control over routing decisions.