PA or PI? Choosing IPv6 Space of Your Own
Audience: anyone getting IPv6 space of their own for the first time: a homelab, a VPS, a small network, someone learning BGP. If you are bringing space to a cloud provider, the BYOIP guides cover the cloud side once you have it.
Last updated: October 2026
1. The short answer
There are two kinds of IPv6 space you can hold in the RIPE NCC's region:
- PA (Provider Aggregatable) space is assigned to you by an LIR from the LIR's own allocation. An isp6 membership includes a /48 of it: 65,536 /64 subnets, assigned to you in the RIPE Database with your certificate on the record, and yours to announce from any network for as long as your membership runs.
- PI (Provider Independent) space is assigned to you by the RIPE NCC itself, with an LIR as your sponsor. It is registered to you, independent of the sponsor, and it moves with you if you change sponsoring LIR.
Neither is the better product. PA is the quicker one to get and the right size for most first networks. PI is for space that must not depend on one LIR.
2. Side by side
| PA from isp6 | PI sponsored by isp6 | |
|---|---|---|
| Assigned by | isp6, from its RIPE NCC allocation | the RIPE NCC |
| RIPE Database status | ASSIGNED |
ASSIGNED PI |
| Record | assigned to you, with your certificate on it, under isp6's maintainer | registered to you or your organisation, under your own maintainer |
| Size | a /48, or a /44 (sixteen /48s) | a /48 for most; larger only for a single site that needs more /64s than a /48 holds |
| What you provide | your details, a mobile number and a photo ID | the same checks, plus an addressing plan and your network topology |
| Who decides | isp6, once you have joined | RIPE NCC staff, after isp6 has reviewed and filed the application |
| Announce it from | any network: a VPS, colocation, home, a cloud | any network |
| If you change LIR | it stays with isp6 | it moves with you to the new sponsor |
| If you stop paying | the space comes back to isp6, and a block you have announced is retired, never handed to anyone else | the space needs a new sponsor, or the RIPE NCC starts to deregister it |
Neither needs an AS Number of your own to be announced. The network that announces your prefix can originate it from its own AS, as long as your ROA names that AS. A cloud provider does exactly this for BYOIP, and some VPS providers with BGP sessions do the same for customers without an ASN. You need your own AS Number when you want one origin across several upstreams; Your First AS Number covers when, and what the RIPE NCC asks for.
3. Which one fits
A homelab, a VPS or a first BGP setup: PA. A /48 is more space than a home network will use, and once you have joined it is yours to announce. Announcing Your /48 from a VPS with BIRD walks through the first announcement.
Several sites that each announce their own space: PA, a /48 per site. Order a /44 (sixteen /48s) or more /48s as you add sites. /44 or /48? sizes it.
Space that must outlive your choice of LIR: PI. A business that cannot renumber if it changes registry, or that wants its address space in its own name independent of any LIR, should hold PI. It asks more of you up front: an addressing plan, your network topology, and an evaluation by the RIPE NCC.
Moving space you already hold: PI space and AS Numbers can transfer to isp6 as sponsoring LIR. See PI space and AS Numbers.
4. What each costs
isp6 prices both in pounds and euros, and keeps them on the product pages: membership and PA space and PI space and AS Numbers. The two models differ in one way worth knowing before you compare: a membership is one yearly fee whatever space you hold, and extra blocks are paid for once. PI space and an AS Number each carry a setup fee and their own yearly sponsorship fee.
5. Further reading
- RIPE NCC: IPv6 Address Allocation and Assignment Policy
- RIPE NCC: AS Number Assignment Policies
- Planning Your isp6 Allocation
Starting out?
A /48 of PA space comes with an isp6 membership, assigned to you in the RIPE Database once you have joined, and yours to announce from a VPS, a rack at home or a cloud.See what membership includes →
This document is provided for informational purposes. Protocol specifications and cloud provider behaviour are subject to change. Consult the linked RFCs and vendor documentation for authoritative, up-to-date information before making architectural decisions.