IPB197: SLAAC and the End of DHCP?

This episode of The IPv6 Buzz explores the technical and operational challenges surrounding IPv6 mostly, a deployment model designed to gradually phase out IPv4 by enabling devices to operate at their highest level of network stack evolution—whether IPv6-only with CLAT (Carrier-Grade NAT64), dual-stack, or IPv4-only. The hosts—Ed Horley, Nick Baraglio, and Tom Coffeen—explain that achieving IPv6 mostly requires running Slack (a local address assignment protocol) to provide a unique IPv6 address to the CLAT function on client devices, since DHCPv6 cannot assign multiple addresses. This creates a key operational friction: enterprises relying on DHCPv6 for IP address tracking, accountability, and security policies find Slack incompatible with their existing workflows, especially when legacy applications or security requirements prevent full IPv6 adoption. The episode highlights a critical gap in the IETF’s standardization process, where enterprise operational realities are underrepresented, leading to solutions like the proposed DHCPv6 address registration extension that remain largely unimplemented. The hosts conclude that Slack is currently a hard requirement for IPv6 mostly, and suggest alternative paths such as adopting zero trust architectures or leveraging streaming telemetry for real-time network visibility to overcome tracking limitations.