Going IPv6-Only: From Myths to Modern Network Realities#

Jen Linkova (Google)

• Why: The clearest statement of the "IPv6-only is becoming the default for high-performing networks" argument, from one of the most experienced IPv6-only operators — and it comes with a deep hands-on companion track elsewhere in the program.
• What: Myth-busting (IPv6 is not "IPv4 with longer addresses," and the transition is not indefinitely deferrable), transition-technology realities in complex enterprise networks, and OS behavior with IPv4 fully disabled. Note: the published deck for this talk is largely charts (APNIC regional adoption stats; an addressing-efficiency example where a /19 was downsized to a /22, saving ~7K addresses). The concrete war stories live in the same speaker's tutorial in this program ("Hacia la transición definitiva de redes IPv6 Only"): Neighbor Discovery state-machine failures and unidirectional connectivity from broken multicast/ND filtering, ICMPv6 filtering breaking PMTUD, NAT64 MTU pitfalls (some vendors default NAT64 MTU to 1280; fragment-extension headers dropped by ACLs), IPv6 IPSec without UDP encapsulation, and AP/switch binding tables silently blocking the N+1 address of multi-address IPv6 hosts. The tutorial also covers DHCP option 108 via DHCP-Relay, 464XLAT with Jool on OpenWrt, DHCPv6-PD, and RFC 8950 (IPv4 routes with IPv6 next-hops) tested on MikroTik RouterOS v7.
• How: Systematic troubleshooting discipline (verify/reproduce → localize/isolate → one-variable controlled changes) applied to IPv6 specifics, with pcap-level ND case studies.
• Where applicable: Enterprise, campus, and access networks moving toward IPv6-only or IPv6-mostly; techniques are general, not Google-specific.