In the context of IPv6, the terms “private” and “public” are handled a little differently than in IPv4, due to the structure and abundance of addresses in IPv6.

IPv6 Addresses and Private Segments

1. Unique Local Addresses (ULAs): In IPv6, the equivalent addresses to the “private” addresses in IPv4 are unique local addresses (ULAs). These addresses are intended for use within local networks and are not routable on the Internet. The range for ULAs is fc00::/7, which technically comprises two blocks: fc00::/8 y fd00::/8.
2. Global Addresses: Global addresses in IPv6 are equivalent to public addresses in IPv4. They are designed to be used on the Internet and are globally routable. The segments for these addresses are varied and are assigned by the IANA and managed regionally by entities such as ARIN, RIPE NCC, etc.

The Segment 2001:db::/64

• The segment you mention, 2001:db::/64, does not seem to fall within the range defined for ULAs (fc00::/7). Without more specific context (like the rest of the digits in the address), it's difficult to determine its exact usage just from 2001:db::/64. However, if it is part of the range 2001:db8::/32, this is a block reserved specifically for documentation and examples in technical documentation, per RFC 3849. This block is not intended for use on private networks or the Internet; Its purpose is purely documentary and exemplary.
• Si 2001:db::/64 is intended as an example of notation and is not 2001:db8::/32, it would be incorrect to consider it as a private segment under current IPv6 regulations and structures.

Conclusion

To determine if an IPv6 segment is private (not globally routable) or public, it is important to check if it is within the range fc00::/7 for ULAs.

Any other address that is not in this range and is routable could be considered global (public) or part of a space reserved for other purposes such as documentation.

Segment 2001:db::/64, based on the typical structure of the documentation, does not qualify as private for internal networks or as a block intended for Internet traffic.