The command show radius statistics (or more specifically, show radius-server statistics in ArubaOS-CX) is used to display counters and statistical information for RADIUS servers. This output includes the number of authentication requests sent, as well as the number of Access-Accept, Access-Reject, and Access-Challenge responses received. While this is not a detailed, event-by-event log, it provides a summary of authentication outcomes, which is crucial for monitoring and troubleshooting RADIUS authentication activity. Among the given choices, it is the most appropriate command for viewing information derived from authentication events.

B. show authentication radius: This is not a valid command in the ArubaOS-CX command-line interface. The show authentication command has other sub-options, but not radius directly.

C. display radius logs: The command verb display is not standard for showing information in ArubaOS-CX; the correct verb is show. This makes the command syntactically incorrect.

D. show aaa radius: This is not a valid command structure in ArubaOS-CX. While show aaa is a valid command root, it does not have a direct radius sub-option.

1. ArubaOS-CX 10.12 Security Guide

Page 101

"Show commands" section.

The guide lists the command show radius-server statistics [name | all-vrfs | vrf ]. The description states it "Displays statistics for RADIUS servers." The example output clearly shows counters for "Authentication Requests

" "Access-Accepts

" and "Access-Rejects

" which represent a summary of authentication log events.

2. ArubaOS-CX 10.12 Command-Line Interface Guide

Pages 2688-2689.

This guide details the show radius-server statistics command

confirming its function and syntax. A review of the guide's command index confirms that show authentication radius

display radius logs

and show aaa radius are not valid commands

validating their exclusion.

According to the standard syslog protocol defined by IETF RFC 5424, severity levels are used to categorize the importance of log messages. The two highest severity levels are Emergency (level 0) and Alert (level 1). 'Emergency' indicates the system is unusable, and 'Alert' signifies that immediate action is required. Both of these levels are reserved for the most critical system or network issues that demand immediate attention from administrators to prevent or address catastrophic failures.

C. Notice: This level (severity 5) is for normal but significant conditions that do not represent an error or a critical issue.

D. Debug: This is the lowest severity level (level 7) and is used to output detailed information for troubleshooting by developers or engineers, not for flagging critical operational problems.

1. IETF RFC 5424

The Syslog Protocol

Section 6.2.1. Severity: This document defines the standard severity levels.

0 Emergency: system is unusable

1 Alert: action must be taken immediately

5 Notice: normal but significant condition

7 Debug: debug-level messages

2. ArubaOS-CX 10.11 Fundamentals Guide

Chapter: Logging

Section: Logging severity levels: This official HPE Aruba guide lists the severity levels used in their network operating systems

which directly align with the RFC standard. It describes 'emergency' and 'alert' as the levels for the most severe events.

Aruba CX switches are designed for modern data center fabrics and campus networks, where overlay technologies are crucial for scalability and multi-tenancy. The primary overlay solution supported and recommended by Aruba is the combination of VXLAN and EVPN. VXLAN (Virtual Extensible LAN) serves as the data plane encapsulation protocol, creating Layer 2 segments over a Layer 3 underlay network. EVPN (Ethernet VPN) functions as the standards-based control plane, using extensions to BGP to efficiently distribute MAC address and IP routing information across the VXLAN fabric, replacing older flood-and-learn mechanisms.

C. GRE: While Aruba CX switches support GRE for specific point-to-point tunneling applications (e.g., User-Based Tunneling), it is not the primary technology for building scalable, multi-tenant data center overlay fabrics.

D. MPLS: Although select high-end Aruba CX switch models support MPLS for service provider or data center interconnect (DCI) use cases, EVPN-VXLAN is the strategic and most commonly deployed overlay solution for data center fabrics within the Aruba CX portfolio.

1. ArubaOS-CX 10.12 VXLAN Guide

Introduction to VXLAN

Page 5: "Virtual Extensible LAN (VXLAN) is a network virtualization technology... ArubaOS-CX supports BGP EVPN as the control plane for VXLAN. BGP EVPN provides a scalable solution for L2 and L3 VPNs over a VXLAN data plane." This document explicitly confirms support for both VXLAN (data plane) and EVPN (control plane) as a combined solution.

2. Aruba Validated Solution Guide: Aruba CX Switching for Data Center Network Fabrics

Technology Overview > Fabric Overlay

Page 11: "The fabric overlay provides logical Layer 2 and Layer 3 virtual network services... This solution uses VXLAN as the overlay encapsulation and BGP EVPN as the overlay control plane protocol." This guide establishes EVPN-VXLAN as the core technology for Aruba's data center fabric solutions.

3. ArubaOS-CX 10.12 MPLS Guide

Introduction

Page 5: This document confirms that MPLS is supported on specific switch series (8325

8360

9300

10000)

positioning it as a distinct technology from the primary EVPN-VXLAN fabric overlay.

Aruba Central provides several security mechanisms to protect the management platform and the devices it controls from unauthorized administrative access. Multi-Factor Authentication (MFA) adds a second layer of security to the login process, requiring users to provide more than just a password. This significantly reduces the risk of compromised credentials. IP Whitelisting restricts access to the Aruba Central portal to a predefined list of trusted IP addresses or subnets, preventing login attempts from any unauthorized location. Both features are fundamental to securing administrative access to the platform.

B. Dynamic VLAN Assignment: This is a network access control feature that assigns authenticated clients to specific VLANs; it does not secure administrative access to the Aruba Central platform itself.

D. Smart Rate Ports: This is a hardware port technology that supports multi-gigabit speeds (e.g., 2.5GbE, 5GbE) on switches. It is a performance feature, not a security mechanism for management access.

1. Aruba Central Help Portal

"Configuring Two-Factor Authentication": This document details the MFA feature

stating

"Aruba Central supports the two-factor authentication feature to provide an additional layer of security to the users of the Aruba Central account. When two-factor authentication is enabled

users are required to enter the username

password

and the verification code to log in to their Aruba Central account."

2. Aruba Central Help Portal

"Managing Security": This section describes the IP Whitelisting feature under "Allowed IP Addresses." It states

"You can configure a list of allowed IP addresses or subnets from which users can log in to the Aruba Central portal. If the allowed IP list is configured

Aruba Central allows access to users logging in from the trusted IP addresses and subnets only."

3. ArubaOS-CX 10.11 Security Guide

"Dynamic VLAN Assignment": This guide explains that dynamic VLAN assignment is used for network clients

stating

"The RADIUS server assigns a VLAN to the client after the client is authenticated." (Page 235). This confirms it is a client access feature

not a platform management security feature.

In ArubaOS-CX, a Quality of Service (QoS) policy is built using class maps and policy maps. A class map is used to classify traffic based on specific criteria. The command class-map match dscp creates a class map (or enters its configuration context) and defines the matching criterion as the Differentiated Services Code Point (DSCP) value in the IP header. This command effectively "assigns" traffic with a specific DSCP value to the defined traffic class for further policy actions like queuing or remarking.

A. qos dscp 46

This is not a valid ArubaOS-CX command for defining a traffic class or assigning a DSCP value within a QoS policy structure.

B. set traffic-class dscp 46

The set command is used within a policy map to apply an action (like remarking), not to define a class. The syntax is also incorrect.

D. ip qos dscp 46

This command syntax is not used in ArubaOS-CX for configuring modular QoS policies. It does not align with the class-map/policy-map framework.

---

1. ArubaOS-CX 10.12 Quality of Service Guide

Page 21

"Configuring a class map". The guide details the process of creating a class map and using match criteria. It shows the command match dscp is used within the class-map context to classify traffic based on its DSCP value. This directly supports the structure and keywords presented in option C.

2. ArubaOS-CX 10.12 Quality of Service Guide

Page 27

"Configuring a policy map". This section shows that actions

such as setting a new DSCP value

are performed using the set dscp command within a policy map

not a class map. This confirms that options B and D

which imply setting or assigning values outside the correct context

are incorrect.

The show system resource-utilization command is the designated utility within the ArubaOS-CX command-line interface for monitoring the switch's real-time performance. It provides an immediate snapshot of both CPU and memory usage. The output details CPU utilization percentages (broken down into user, system, and idle states) and memory statistics (including total, used, and free memory). This command is fundamental for network administrators to assess the operational health and current load on the switch hardware.

A. show cpu-memory: This is not a valid command in the ArubaOS-CX CLI. While descriptive, the correct syntax is different.

C. show log: This command displays the system's event log buffer, which records historical events, not real-time resource utilization statistics.

D. show clock: This command is used exclusively to display the current system date and time, and has no function related to resource monitoring.

1. Hewlett Packard Enterprise. (2022

May). ArubaOS-CX 10.10 CLI Reference Guide. Part Number: 5200-8207.

Page 2618: The entry for show system resource-utilization states

"Displays the system resource utilization information. This command displays the CPU and memory utilization for the switch." An example output confirms it shows real-time CPU and memory data.

Page 2188: The show log command is described as displaying the contents of the event log.

Page 1988: The show clock command is described as displaying the current system clock time.

A search of the document confirms that show cpu-memory is not a listed command.

The show interface trunk command on an Aruba CX switch is used to display detailed information about all interfaces configured in trunk mode. The output includes the port's status, the native VLAN, and the list of allowed (tagged) VLANs. An administrator uses this information to verify the local configuration and compare it against the configuration of the peer switch connected to the trunk. A discrepancy in the native VLAN or the allowed VLAN list between the two ends of the link constitutes a VLAN mismatch, which this command helps to identify.

A. show vlan port: This command shows which VLANs are tagged or untagged on a specific port, but it is less direct for diagnosing trunk-specific mismatches compared to the dedicated trunk summary command.

B. show trunk vlan: This is not a valid command in the Aruba CX command-line interface (CLI). The syntax is incorrect.

D. display trunk status: The display command verb is characteristic of the HPE Comware OS, not the Aruba CX AOS-CX operating system, which uses the show verb.

1. Aruba CX 10.12 CLI Reference Guide

Page 1989

"show interface trunk" command.

The guide details the show interface trunk command

describing its function: "Shows information for interfaces configured as a trunk." The output fields shown in the guide

such as "Native VLAN" and "Allowed VLANs

" are the exact parameters required to check for VLAN mismatches on a trunk link.

2. ArubaOS-CX VLAN Configuration Guide

"Configuring VLANs" section.

This guide explains the concepts of native and tagged VLANs on trunk ports. It implicitly supports the use of show commands like show interface trunk to verify these configurations

which is the basis for identifying mismatches. For example

it states

"To display VLAN trunk configuration information

use the show interface trunk command."

To assign an IP address to a Switched Virtual Interface (SVI), which is a logical Layer 3 interface on a switch, a two-step process is required in the command-line interface (CLI). First, the administrator must enter the specific VLAN interface configuration context using the interface vlan command. Once in the interface context, the ip address / command is used to assign the actual IPv4 address and subnet mask to that logical interface. These two commands are fundamental and sequential for this configuration task.

ip route 0.0.0.0/0: This command configures a static default route for the device's routing table; it does not assign an IP address to an interface.

show ip interface brief: This is a verification command used to display the status and IP configuration of interfaces, not to configure or assign an address.

1. HPE ArubaOS-CX 10.12 Fundamentals Guide

Page 119

"Configuring an IPv4 address on a VLAN interface". The guide explicitly lists the required commands in order:

configure

interface vlan

ip address /

This directly validates that commands interface vlan 10 (A) and ip address 192.168.1.1/24 (B) are the correct steps.

2. HPE ArubaOS-CX 10.12 Command-Line Interface Guide

Page 1887

"ip address". This section details the ip address command

specifying its use within an interface context (config-if

config-if-vlan) to configure an IPv4 address.

3. HPE ArubaOS-CX 10.12 IP Routing Guide

Page 37

"Configuring a static IPv4 route". This document shows that the ip route command (Option C) is used for configuring static routes

a distinct function from assigning an IP address to an interface.

The qos trust dscp command is configured within an interface context on an HPE ArubaOS-CX switch. This command establishes a trust boundary, instructing the switch to honor the Differentiated Services Code Point (DSCP) value present in the IP header of incoming packets. By trusting the DSCP marking, the switch uses this value to classify the traffic and assign it to the appropriate internal quality of service queue for prioritization. This ensures that upstream QoS policies are maintained as traffic traverses the switch.

B. apply trust-dscp: This is not a valid command syntax in ArubaOS-CX for establishing a QoS trust boundary. The apply keyword is typically used for policies, not trust settings.

C. traffic trust dscp: The traffic keyword is incorrect for this context. QoS trust settings are configured under the qos command hierarchy in the ArubaOS-CX command-line interface.

D. qos enforce dscp: The enforce keyword implies a policing or rate-limiting action. This is different from trust, which simply accepts and uses the existing QoS markings for classification.

---

1. HPE ArubaOS-CX 10.12 Quality of Service Guide

Page 19

Chapter 3: "Configuring QoS trust mode". The guide explicitly states

"To trust the DSCP value in the IP packet header

enter the command qos trust dscp."

2. HPE ArubaOS-CX 10.12 Command-Line Interface Guide

Page 2999

"Interface context commands". The command qos trust dscp is listed with the description: "Configures the QoS trust mode of the interface to dscp."

ArubaOS-CX switches support the two primary, standardized modes of Protocol Independent Multicast (PIM). PIM Sparse Mode (PIM-SM) is an efficient mode for widespread networks where multicast group members are sparsely distributed. It uses an explicit join mechanism, where routers only forward multicast traffic to segments with active receivers. PIM Dense Mode (PIM-DM) is designed for networks where multicast group members are densely populated. It employs a flood-and-prune mechanism, initially flooding traffic to all routers and then pruning branches that do not have active receivers. Official Aruba documentation explicitly confirms support for both PIM-SM and PIM-DM.

C. PIM Hybrid Mode: This is not a standard IETF-defined PIM mode and is not a feature supported or documented for Aruba CX switches.

D. PIM Static Mode: This is not a standard PIM operational mode. While static multicast routes (mroutes) can be configured, it is not a distinct PIM mode like Sparse or Dense Mode.

1. ArubaOS-CX 10.12 IP Multicast Guide

Page 29

"PIM overview" section. The document states: "ArubaOS-CX supports Protocol Independent Multicast-Sparse Mode (PIM-SM) and Protocol Independent Multicast-Dense Mode (PIM-DM)."

2. ArubaOS-CX 10.12 Fundamentals Guide

Page 311

"IP multicast" section. The guide mentions: "ArubaOS-CX supports PIM-SM (Protocol Independent Multicast - Sparse Mode) and PIM-DM (Protocol Independent Multicast - Dense Mode)..."