Aruba Associate flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Non-overlapping 2.4 GHz channels

In 2.4 GHz only channels 1, 6, and 11 are commonly non-overlapping because each 20 MHz channel needs about 25 MHz separation; using others causes adjacent-channel interference.

DFS radar event

When a 5 GHz AP detects radar on a DFS channel, it must vacate within 60 seconds and not use that channel for a 10-minute non-occupancy period.

SNR and modulation

Signal-to-noise ratio determines the highest modulation and coding scheme; roughly 25 dB SNR supports high MCS rates while below 10 dB forces low rates and retries.

Free-space path loss formula

FSPL(dB) = 20log10(d) + 20log10(f) + 32.44 with distance in km and frequency in MHz; doubling distance adds about 6 dB of loss.

802.11r fast BSS transition

802.11r enables fast BSS transition by pre-authenticating and caching keys so a roaming client skips full 802.1X reauthentication, reducing handoff time.

WPA3 SAE

WPA3-Personal replaces the pre-shared key handshake with Simultaneous Authentication of Equals, a password-authenticated key exchange that resists offline dictionary attacks.

Beacon interval

APs transmit beacons advertising the SSID, supported rates, and capabilities; the default interval is 100 ms, and a longer interval saves airtime but slows discovery.

Instant AP virtual controller

In an Aruba Instant cluster, one AP is elected virtual controller and holds the configuration, pushing it to member APs without a hardware controller.

Mobility Master role

The Aruba Mobility Master is an optional control-plane node that manages multiple Mobility Controllers, centralizing configuration and licensing in ArubaOS 8.x.

AOS-CX VSX

VSX is the AOS-CX high-availability pair technology using an inter-switch link and keepalive, providing active-active forwarding instead of traditional stacking.

ClearPass Policy Manager

ClearPass is Aruba's policy server providing RADIUS and TACACS+, 802.1X, MAC authentication, role mapping, and guest workflows for wired and wireless access.

Local bridging

Local bridging forwards client traffic directly from the AP onto the local VLAN instead of tunneling it to the controller, reducing controller load and latency.

Aruba Central

Aruba Central is a cloud SaaS platform for onboarding, configuring, monitoring, and troubleshooting Aruba APs, switches, and gateways over outbound HTTPS.

AP discovery methods

An AP finds its controller using DHCP option 43, DNS resolution of aruba-master, or a broadcast on the local subnet before joining and downloading configuration.

AP monitor mode

In monitor mode an AP stops broadcasting SSIDs and dedicates its radios to scanning for rogue APs and RF threats, feeding IDS and RF protection.

ARM channel and power

Adaptive Radio Management scans the RF neighborhood and automatically assigns channels and transmit power to reduce interference and balance coverage.

AP primary and backup controller

An AP can be configured with a primary and backup controller; if the primary fails, the AP fails over and re-downloads its configuration from the backup.

Virtual AP profile

A virtual AP profile defines an SSID, its security, VLAN, and forwarding mode; it must be attached to an AP group to be broadcast.

PoE power budgets

802.3af delivers about 12.95 W at the device, 802.3at about 25.5 W, and 802.3bt up to 60 or 90 W; Wi-Fi 6E APs often need at least 802.3at.

802.1X authentication flow

The supplicant authenticates through the authenticator, which relays EAP to the RADIUS server; on success the server returns attributes that map the user to a role.

Role-based access control

After authentication, ArubaOS assigns a user role that determines VLAN, ACLs, and captive-portal policy, often derived from RADIUS attributes.

MAC authentication fallback

MAC authentication bypass authenticates devices by MAC address when 802.1X is unsupported; because MACs can be spoofed it should be paired with restrictive roles.

RADIUS CoA

Change of Authorization lets the RADIUS server modify a live session's role, VLAN, or ACL without forcing the client to reauthenticate.

ClearPass enforcement policy

An enforcement policy evaluates role and request attributes and returns enforcement profiles that assign VLAN, role, or ACL to the authenticated session.

Guest VLAN isolation

A guest VLAN uses ACLs to block access to internal RFC1918 subnets and to other guest clients, confining guests to internet-only access.

SNMPv3 security

SNMPv3 adds authentication and privacy (encryption) with user-based security, making it preferable to SNMPv2c community strings for monitoring Aruba devices.

show ap database

This controller command lists known APs with name, group, IP, model, and state flags, helping confirm which APs have joined and their status.

Client troubleshooting order

Check association and authentication, then DHCP address assignment, then assigned role and ACLs, then datapath sessions, and finally RF signal and retries.

High channel utilization

High channel utilization with few clients usually indicates interference, a non-Wi-Fi source, or excessive management frames rather than client load.

Syslog severity levels

Syslog uses levels 0 to 7, from emergency through debug; filtering by severity and facility keeps controller logs manageable on a central server.

Central groups and sites

In Aruba Central, groups hold configuration and sites hold location and topology data; each device belongs to exactly one group and one site.

Central licensing tiers

Aruba Central offers Foundation for monitoring and basic configuration and Advanced for AI insights, WLAN design, and advanced security, licensed per device.