IPv6 Address Lookup

What an IPv6 lookup can tell you

The reliable half of the answer comes from registry records. Regional registries publish which organisation holds each IPv6 prefix, so the network owner, the ISP and the autonomous system number are solid facts rather than estimates.

The location half is inferred. Commercial databases estimate where a prefix is used, and for IPv6 they have less to work with than for IPv4: the blocks are newer, enormously larger, and there are fewer measurements mapping them to physical places. Treat country as trustworthy and city as a hint.

IPv6 prefixes, not addresses

One practical difference from IPv4: with IPv6 you are almost always looking at a prefix rather than a single meaningful address. A home connection is typically given a /56 or /64, and individual device addresses inside it rotate every few hours thanks to privacy extensions.

So an IPv6 address seen in a log identifies a connection at a moment in time, not a device permanently. If you are correlating log entries, match on the network prefix — the first four groups — rather than the full address.

Reserved ranges you will meet

An address starting fe80 will never return a useful lookup: it is local to one network segment and has no public registration. The same goes for fc00::/7.

To check your own address instead, use the IPv6 address checker, or the general IP lookup for IPv4 work.