Aruba ACDA flashcards

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

Design Methodology Phases

Structured sequence from requirements gathering through conceptual, logical, and physical design, then implementation, validation, and optimization. Each phase produces artifacts feeding the next.

Functional Requirements

Statements describing what the network must do for users and applications, such as supporting voice, guest access, or specific throughput per client.

Availability Formula

Availability equals MTBF divided by the sum of MTBF and MTTR. It expresses the fraction of time a system is operational and guides redundancy decisions.

Oversubscription Ratio

Ratio of aggregate edge port bandwidth to the uplink bandwidth serving those ports. Common access-to-distribution values are around 20:1 for endpoint traffic.

Two-Tier Campus Design

Collapsed core topology where core and distribution functions share the same switches. Suitable for smaller campuses with limited scale and simpler policy needs.

PoE Power Budget

Total wattage a switch can deliver to powered devices across all ports. Design must sum device draw and stay within budget, accounting for 802.3af/at/bt classes.

Link Aggregation Group

Bundle of parallel links treated as one logical link using LACP. Members must match in speed, duplex, and VLAN configuration; up to eight active links per group.

MSTP Instances

Multiple Spanning Tree maps groups of VLANs to spanning-tree instances, reducing topology complexity and enabling load sharing across redundant links.

Cat6A Distance Limit

Cat6A twisted-pair cabling supports 10GBASE-T to 100 meters. It is a common choice for access-layer copper runs in campus wiring design.

Distribution Layer Role

Aggregates access switches, enforces routing and policy boundaries, and provides redundancy between access and core. It is where inter-VLAN routing typically occurs.

Cell Edge Signal Target

Design target for received signal strength at the coverage boundary. Common values are about -67 dBm for voice and -72 dBm for data applications.

Non-Overlapping 2.4 GHz Channels

In North America the non-overlapping 2.4 GHz channels are 1, 6, and 11. Using only these minimizes co-channel interference in a reuse plan.

Capacity-Based AP Count

AP quantity derived by dividing expected concurrent clients by a target clients-per-AP figure. Complements coverage-based counting in high-density environments.

Co-Channel Interference

Interference when multiple APs use the same channel in overlapping coverage areas. Managed through channel reuse planning and transmit power tuning.

Band Steering

Feature that encourages dual-band clients to associate on 5 GHz, relieving congestion on 2.4 GHz and improving overall capacity and throughput.

Roaming Overlap

Deliberate overlap between adjacent AP cells, often 15-20 percent, so clients can roam without dropping sessions. Consistent SSID and security are required.

SD-WAN Path Selection

Policy-based routing that steers application traffic across multiple WAN transports based on latency, jitter, loss, and business priority.

Hub-and-Spoke WAN

Topology where branch sites connect to a central hub. It centralizes policy and security but adds latency for branch-to-branch traffic.

MPLS WAN

Private carrier service with label-based forwarding and SLA-backed performance. Often used for latency-sensitive traffic requiring predictable paths.

Branch Bandwidth Sizing

Summing peak application demand per branch and adding headroom, commonly 20-30 percent, to absorb growth and bursty traffic.

WAN QoS Marking

DSCP values set at the edge must be preserved across the WAN. Edge devices map markings to per-hop behavior and shape traffic to contracted rates.

Dual WAN Failover

Design pattern using two independent WAN links, often different carriers or media, so traffic reroutes when the primary path fails.

Defense in Depth

Layering multiple independent security controls, such as firewalls, segmentation, AAA, and monitoring, so no single failure exposes the network.

802.1X NAC

Port-based access control that authenticates users or devices via a supplicant and RADIUS server before granting network access. MAB is a fallback for non-supplicants.

Micro-Segmentation

Dividing the network into fine-grained zones with policy between them, limiting lateral movement if a host is compromised. A core Zero Trust practice.

Guest Network Isolation

Guest traffic is placed on a separate VLAN or tunnel with captive portal authentication and no route to internal subnets, protecting corporate resources.

WPA3-Enterprise

Wireless security mode using 802.1X with RADIUS plus stronger encryption. WPA3 adds SAE for personal mode and forward secrecy protections.

Security Zones

Logical separation of untrusted internet, DMZ, internal user, and management planes. Firewall policy governs traffic between zones.

FCAPS Model

Management framework covering Fault, Configuration, Accounting, Performance, and Security. Used to structure monitoring and operations design.

SNMPv3 Security

Version 3 of SNMP adds authentication and encryption of management traffic. Preferred over v1 and v2c, which send community strings in clear text.

Syslog Severity Levels

Numeric levels 0 through 7, where 0 is emergency and 7 is debug. Centralized logging to a syslog server or SIEM supports correlation and retention.

Flow Telemetry

NetFlow, sFlow, and IPFIX export flow records describing traffic conversations. Used for capacity planning, anomaly detection, and security analysis.