Knowledge base · TOPIC-14

IPv4 works while IPv6 is degraded

Short answer: yes. IPv4 and IPv6 have separate addresses and routes. Applications may race or fall back between them, so a successful page can conceal a failing family.

RFC 8200 specifies IPv6, while Happy Eyeballs describes how applications can reduce delay when one family is impaired. Those protocol facts do not prove that a specific timeout was caused by IPv6. Family-specific DNS, connect, TLS, timing, and route evidence are required.

Avoid treating “IPv6 not detected” as total Internet failure. Conversely, do not infer that AI traffic used IPv6 simply because the interface has an IPv6 address. A safe investigation holds other variables steady, measures each family explicitly, and records unavailable evidence as incomplete rather than invented.

Tivor Open Probe V0.1 does not provide IPv4-versus-IPv6 path comparison. Its local report provides bounded local context, but it does not claim which family explains an application failure. Use the Scanner for its limited browser view and Open Probe for supported local evidence. Related: provider outage versus local network failure.