The 4.10 branch continued to mature Cisco’s support for IPv6 inside the tunnel, allowing administrators to push IPv6 routes to clients more reliably in dual-stack environments.

The represents the apex of the mature, reliable 4.x branch. It offers exceptional stability, wide OS coverage, and enterprise-grade security features like Always-On VPN, HostScan posture, and Umbrella roaming. However, its lack of TLS 1.3, pending EoL in 2025, and incompatibility with newer operating systems (macOS Sonoma, Windows on ARM) signals that it is a legacy champion—not a future-proof solution.