A root-protected port is persistently in a blocked state. What is the most likely cause?

The port is configured with BPDU protection

The port is not configured with root protection

The port is experiencing a duplex mismatch

A superior BPDU is being received from a device on the other end

Which Junos CLI command configures the maximum number of MAC addresses allowed on an interface for port security?

set ethernet-switching-options secure-access-port interface ge-0/0/1 mac-limit 5

set security port-security interface ge-0/0/1 maximum-mac 5

set interfaces ge-0/0/1 unit 0 family ethernet-switching port-security max-mac 5

set vlans default interface ge-0/0/1 mac-limit 5

A network administrator is troubleshooting a port security issue where a legitimate device is being blocked from the network. The port security configuration allows a maximum of 3 MAC addresses, and the violation action is shutdown. The administrator checks the port security status and sees that the port is error-disabled. What is the most likely cause of this issue?

The legitimate device is sending BPDUs, and BPDU protection was triggered.

The switch was rebooted, and the port security configuration was lost.

The port was manually disabled by an administrator.

The legitimate device's MAC address was not in the allowed list, and the port exceeded the maximum MAC count.

A port security-enabled interface is error-disabled. Which log message would most likely indicate the cause?

Routing protocol neighbor down on ge-0/0/1

Spanning tree topology change detected

MAC address limit exceeded on interface ge-0/0/1

What does the log message 'BPDU received on protected port ge-0/0/1' indicate?

The port is in a spanning-tree blocking state

BPDU protection has detected an unauthorized BPDU and error-disabled the port

The port is functioning normally and forwarding BPDUs

The port has been manually disabled by an administrator

Juniper NetworksCertified Specialist, Enterprise Routing and Switching (JNCIS-ENT)

Domain 3Objective 6

Configure, Monitor, or Troubleshoot Layer 2 Protection and Port Security JN0-352 Practice Questions (Page 4)

Part of the Layer 2 Security domain, which makes up ~13% of our current practice bank. Juniper Networks does not publish an official question count, but from its 90-minute exam (~35–60 total, ~5–8 in this domain), expect 1–1 from this objective — we provide 30 practice questions to prepare you well beyond it. (estimate)

30questions here

6free pages

14concepts

14 Concepts in This Objective

Layer 2 protection mechanisms
Port security basics
Configuring port security
Monitoring port security
Troubleshooting port security
Configuring BPDU protection
Monitoring BPDU protection
Troubleshooting BPDU protection
Configuring root protection
Monitoring root protection
Troubleshooting root protection
Configuring loop protection
Monitoring loop protection
Troubleshooting loop protection

Questions 16–20

16foundation · easy
A root-protected port is persistently in a blocked state. What is the most likely cause?
Select an answer first
17foundation · easy
Which Junos CLI command configures the maximum number of MAC addresses allowed on an interface for port security?
Select an answer first
18application · medium
A network administrator is troubleshooting a port security issue where a legitimate device is being blocked from the network. The port security configuration allows a maximum of 3 MAC addresses, and the violation action is shutdown. The administrator checks the port security status and sees that the port is error-disabled. What is the most likely cause of this issue?
Select an answer first
19foundation · easy
A port security-enabled interface is error-disabled. Which log message would most likely indicate the cause?
Select an answer first
20foundation · easy
What does the log message 'BPDU received on protected port ge-0/0/1' indicate?
Select an answer first

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