Chapter 4

Operational considerations

The shared /48 offers ample room for structured deployments, but it must be handled as shared internal-use space and kept away from public routing.

4.1Address-plan hierarchy

A /48 contains 256 /56s and 65,536 /64s. Most residential and small-business deployments can therefore reserve generous, non-overlapping blocks for sites, functions, or growth.

Example blockPossible roleCapacity
2602:f925:ad:0000::/56Primary site256 /64 LANs
2602:f925:ad:0100::/56Branch site256 /64 LANs
2602:f925:ad:1000::/56Infrastructure or lab256 /64 LANs
2602:f925:ad:ff00::/56Reserved future use256 /64 LANs

The table is illustrative. The project does not assign these blocks or reserve them exclusively for any user.

4.2Multi-site thinking

Engineers should apply the same planning discipline used with shared RFC1918-style space: create an organization-wide hierarchy before deploying multiple sites, reserve capacity rather than consuming blocks sequentially, and assume that an unrelated network may independently use the same addresses.

Within one organization

Even modest planning can make the /48 suitable for extensive multi-site use without internal overlap. The risk appears when separately planned organizations later interconnect.

4.3VPNs, acquisitions, and interconnection

When two independently administered networks using this prefix are joined, overlapping routes may require selective renumbering, additional translation, segmentation, or policy routing. This is not unique to this project; it is an inherent consequence of all non-exclusive internal address conventions.

4.4Prevent route leakage

Local controls remain mandatory

Every adopting network should explicitly prevent 2602:f925:ad::/48 and its more-specific routes from being advertised toward an ISP, transit provider, route server, or public peering session.

Origin-side blackholing and RPKI policy are safeguards, not substitutes for correct edge configuration. Recommended practice includes explicit outbound route filters, discard routes where appropriate, configuration review, and route-monitoring alerts.

4.5Prefix-length mapping

NPTv6 is simplest when the internal and external prefixes being mapped have corresponding lengths. A site receiving a /56 can map one internal /56 from the project /48. A /48 external allocation can map the entire internal /48. Smaller delegations require selecting a correspondingly sized internal portion.