With the Aruba CX switch configuration, what is the first-hop protocol feature that is used for VSX L3 gateway as per Aruba recommendation?

Active Gateway is the recommended and purpose-built first-hop redundancy protocol (FHRP) for Aruba CX switches operating in a VSX (Virtual Switching Extension) environment. It enables both VSX switches to simultaneously process and route traffic for a given VLAN (SVI), creating a true active-active L3 gateway. This is achieved by configuring a shared virtual IP address and a common virtual MAC address on the SVI of both switches. This design eliminates suboptimal traffic paths inherent in traditional active-standby protocols like VRRP.

B. Active-Active VRRP: This is a conceptual term. The specific Aruba feature that provides this active-active gateway functionality within a VSX pair is named "Active Gateway," not "Active-Active VRRP."
C. SVI with vsx-sync: An SVI is the Layer 3 interface, and vsx-sync is a command to synchronize configurations. These are components of the setup, but "Active Gateway" is the name of the protocol feature itself.
D. VRRP: Standard VRRP (Virtual Router Redundancy Protocol) operates in an active-standby model. Using it in a VSX topology would result in one switch being the active gateway, creating inefficient traffic flows.

1. ArubaOS-CX VSX Configuration Guide for 10.12: In the "VSX active gateway" chapter, it states, "Active gateway enables a pair of VSX switches to appear as a single default gateway to downstream devices... Both VSX switches simultaneously route traffic that is sent to the gateway." This document clearly identifies Active Gateway as the solution for VSX L3 gateways.

2. ArubaOS-CX Layer 3 Routing Configuration Guide for 10.12: In the "First Hop Redundancy Protocols" chapter, under the "Active gateway" section, it details, "Active gateway is an Aruba proprietary feature that provides gateway redundancy in a VSX pair... Active gateway is recommended over VRRP for VSX." This explicitly confirms it as the recommended protocol over standard VRRP.

3. ArubaOS-CX Fundamentals Guide, Rev 21.11: In Chapter 6, "Virtual Switching Extension (VSX)," the section "VSX L3 active gateway" explains, "To provide redundancy for the default gateway, Aruba has developed the active gateway feature. It is an FHRP that is active on both VSX switches at the same time." This reinforces that Active Gateway is the specific Aruba feature for this purpose.