Buildkite has introduced session IP address pinning to enhance security, ensuring sessions originate from the IP address that created them, which is effective for IPv4 but presents challenges for IPv6 and dual-stack connections. IPv6's vast address space and dynamic addressing, where devices change addresses within subnets to avoid tracking, complicate session pinning, leading to frequent re-authentication requests for users. The Happy Eyeballs algorithm, which switches between IPv4 and IPv6 based on response times, further exacerbates this issue. To improve the user experience, Buildkite is considering allowing sessions to pin both IPv4 and IPv6 addresses and pinning an IPv6 /64 subnet rather than a single address, aligning IPv6 behavior with IPv4's seamless IP switching without re-authentication. These potential improvements aim to address the challenges of dual-stack IPv6 connections while maintaining security and enhancing user experience.