Aruba Associate key terms

Service Set Identifier: the logical name broadcast in beacon frames that client devices use to identify and join a specific wireless network. Multiple SSIDs can be mapped to different VLANs and security policies on the same access point.

Basic Service Set Identifier: the 48-bit MAC address that uniquely identifies a single access point radio and its basic service set. Clients associate to a BSSID, which is typically the radio's MAC address.

The process by which a wireless client moves its association from one access point to another while maintaining network connectivity. Layer 2 roaming stays within a subnet; Layer 3 roaming preserves the client's IP address across subnets.

A defined range of radio frequencies used for wireless transmission. In 2.4 GHz, channels are 5 MHz apart but only 1, 6, and 11 are non-overlapping; in 5 GHz, channels are 20 MHz wide and more numerous.

Degradation of signal quality when multiple access points or clients transmit on the same channel within range of each other, causing contention and reduced throughput. Proper channel planning and transmit power tuning mitigate it.

Combining two or more adjacent 20 MHz channels into a wider channel (40, 80, or 160 MHz) to increase throughput. Wider channels reduce the number of available non-overlapping channels and can increase interference in dense deployments.

The radio frequency output level of an access point or client, usually expressed in dBm. Higher power extends coverage but can cause co-channel interference and sticky clients; Aruba controllers can auto-tune it via ARM.

Received Signal Strength Indicator: a relative measure of the power level a client or AP receives from a transmitting device, typically in dBm (negative values). It helps determine coverage and roaming thresholds.

Signal-to-Noise Ratio: the difference in dB between the received signal strength and the noise floor. Higher SNR supports higher data rates; values below roughly 20 dB often cause retries and lower throughput.

The background RF energy level present in a channel from sources other than the intended transmitter, measured in dBm. A higher noise floor reduces SNR and can be caused by interference or nearby electronics.

Multiple-Input Multiple-Output: a radio technology using multiple antennas at transmitter and receiver to improve throughput and reliability through spatial multiplexing and diversity. Aruba APs commonly support 2x2, 3x3, or 4x4 MIMO.

A Wi-Fi standard operating in the 5 GHz band that introduced wider channels (up to 160 MHz), higher-order modulation (256-QAM), and multi-user MIMO. It is backward compatible with earlier 802.11 standards.

An Aruba appliance or virtual instance that centralizes configuration, security policy, and roaming for access points. It terminates CAPWAP tunnels, manages RF, and enforces roles and firewall policies for wireless clients.

An Aruba controller, typically deployed in pairs, that manages configuration and software images for multiple Mobility Controllers in large networks. It does not carry user traffic but provides centralized control and redundancy.

Control and Provisioning of Wireless Access Points: the protocol used between Aruba access points and controllers to carry management, control, and optionally data traffic. It uses UDP ports 5246 (control) and 5247 (data).

A device that provides wireless connectivity by bridging Wi-Fi clients to the wired network. Aruba APs can operate in controller-managed, Instant, or Central-managed modes depending on the deployment model.

An Aruba access point that runs without a dedicated controller, with one AP elected as the virtual controller to manage the cluster. It is suited to smaller sites and can be converted to controller-managed mode.

The software function in an Aruba Instant deployment where one access point assumes the management role for the cluster, providing a single IP address for configuration and monitoring. It can migrate if the host AP fails.

A group of Aruba Instant access points that share configuration and coordinate wireless services under one virtual controller. Clusters simplify management and enable fast roaming within the group.

An Aruba controller deployment model where one controller acts as master for configuration and management, and other controllers operate as locals to terminate AP tunnels and client traffic. It supports scale and redundancy.

Adaptive Radio Management: an Aruba feature that automatically selects channels and transmit power for access points to reduce interference and optimize coverage. It can also adjust client steering and airtime fairness.

An Aruba security model that assigns a user role to a client based on authentication or device attributes, then applies firewall policies and VLAN assignments to that role. Roles can be derived from 802.1X, MAC, or captive portal.

An IEEE standard for port-based network access control that authenticates supplicants via an authentication server (typically RADIUS) before granting network access. In Wi-Fi, it commonly uses EAP methods over WPA2/WPA3-Enterprise.

Remote Authentication Dial-In User Service: a protocol used to centralize authentication, authorization, and accounting. Aruba controllers and Instant APs forward client credentials to a RADIUS server and receive role or VLAN attributes.

A web page presented to unauthenticated clients that requires them to log in, accept terms, or register before network access is granted. Aruba supports internal and external captive portal modes for guest access.

A network service that provides visitors with temporary, often isolated internet access. Aruba implements it with guest SSIDs, captive portal authentication, and firewall policies that restrict access to internal resources.

Virtual Local Area Network: a logical segmentation of a physical network at Layer 2. Aruba maps SSIDs and user roles to VLANs to separate traffic such as guest, corporate, and management.

Aruba's on-premises network management platform for monitoring, configuration, and reporting across multivendor wired and wireless infrastructure. It provides historical trends, alerts, and compliance reporting.

A cloud-based management platform for Aruba wired, wireless, and SD-WAN devices. It offers configuration, monitoring, AI insights, and guest management through a single dashboard without on-premises servers.

Simple Network Management Protocol: a standard used by management systems to poll devices and receive traps. Aruba controllers and APs expose MIBs for monitoring interface status, client counts, and alarms.

A standard protocol for sending event and error messages from network devices to a central logging server. Aruba controllers and APs can forward logs to syslog for troubleshooting and audit trails.

The sequence an Aruba access point follows at startup: loading firmware, discovering a controller or virtual controller via DHCP options, DNS, or broadcast, then establishing a CAPWAP tunnel and downloading configuration.

A DHCP option used to provide Aruba access points with controller IP addresses during boot, enabling discovery when the AP and controller are on different subnets. It is commonly configured as a vendor-specific option.

An Aruba feature that continuously monitors client RF conditions and steers clients to the best access point and band. It helps resolve sticky client and load-balancing issues without manual intervention.

An Aruba RF optimization feature that uses a periodic planning algorithm to assign channels and transmit power across access points, improving on traditional per-AP ARM decisions in dense deployments.

The latest Wi-Fi security certification that improves on WPA2 with stronger handshakes, protected management frames, and optional 192-bit enterprise mode. It addresses offline dictionary attacks on WPA2-Personal.

A security feature (802.11w) that encrypts certain management frames such as deauthentication and disassociation to prevent spoofing and denial-of-service attacks. It is required for WPA3 and optional for WPA2.

Multi Pre-Shared Key: an Aruba feature that allows each client or device to use a unique pre-shared key on the same SSID, improving security and simplifying key rotation compared with a single shared PSK.

An Aruba access point mode where client data traffic is encapsulated and sent to the controller rather than bridged locally. It centralizes policy enforcement but adds latency and controller load.