ACA Cheat Sheet 2026

The 30 highest-yield ACA facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is a characteristic of a MAC address? → Assigned by the manufacturer
2. Which STP port state actively forwards traffic in a classic 802.1D implementation? → Forwarding
3. In Aruba AirWave, what does the 'Rogue AP' detection feature identify? → Unauthorized access points not managed by the organization
4. What does LLDP (Link Layer Discovery Protocol) help you determine during troubleshooting? → Which devices are directly connected to each network port
5. Which Aruba Central feature helps identify which clients are experiencing poor wireless connectivity? → Client Health
6. Which command on an Aruba CX switch shows the IP routing table? → show ip route
7. What is Aruba's Zero Touch Provisioning (ZTP) feature used for? → Automatically configuring new devices when they connect to the network
8. What does the subnet mask /24 indicate about an IP network? → The first 24 bits are the network portion, leaving 8 bits for hosts (254 usable hosts)
9. What does 'flapping' mean in the context of network interfaces or routing protocol neighbors? → A port or neighbor repeatedly going up and down in rapid succession
10. On Aruba AOS-CX switches, where are QoS policies most commonly applied to enforce traffic prioritization? → On ingress and egress interfaces using QoS profiles
11. Which protocol is used to assign IP addresses automatically? → DHCP
12. Which Aruba tool is used for network configuration management with version control capabilities? → Aruba NetEdit
13. What does Aruba AirWave VisualRF provide to network administrators? → A floor plan-based view of AP placement and wireless coverage
14. What is the purpose of Aruba's Client Match feature? → To intelligently steer clients to the best AP or radio band based on RF conditions
15. What is a DHCP relay agent used for? → To forward DHCP broadcasts across routed network boundaries to a centralized DHCP server
16. In OSPF, what triggers a Shortest Path First (SPF) recalculation? → A change in the link-state database due to a new or changed LSA
17. Which queuing mechanism gives absolute priority to delay-sensitive traffic, ensuring it is always dequeued first? → Strict Priority Queuing (PQ)
18. What is the difference between an access port and a trunk port on an Aruba switch? → Access ports carry one VLAN; trunk ports carry multiple VLANs
19. What DSCP value is assigned to Best Effort (BE) traffic, which receives no special QoS treatment? → DSCP 0
20. Which IEEE standard defines VLAN tagging on trunk links? → IEEE 802.1Q
21. In the context of Aruba routing, what is a VLAN interface (SVI) used for? → To route traffic between VLANs at Layer 3 on a multilayer switch
22. Which Aruba product line provides SD-WAN capabilities for branch office deployments? → Aruba EdgeConnect
23. What does IPsec provide in Aruba VPN deployments? → Encrypted and authenticated tunnels for secure site-to-site or remote access connectivity
24. Which Aruba diagnostic tool performs active tests simulating real user traffic to measure network performance? → Aruba Central Network Tests
25. What key feature does AirWave provide? → Network monitoring and visibility
26. Which Aruba Central feature provides AI-powered insights to identify and resolve network issues? → AI Insights
27. Which type of VLAN is dedicated to carrying voice traffic with priority tagging on Aruba switches? → Voice VLAN
28. What is the valid range of 802.1p Class of Service (CoS) values in an 802.1Q tag? → 0–7
29. What type of routing protocol is OSPF? → Link-state routing protocol
30. What is a native VLAN on an 802.1Q trunk port? → The VLAN whose traffic is sent untagged across the trunk