Types of IPv4 Address Allocations
Not all IPv4 addresses are equal in terms of how they can be transferred and used. Understanding the distinction between Legacy, PI, and PA addresses is essential.
Legacy Addresses
Legacy IPv4 addresses were allocated before the RIR system was established (pre-1997 for most regions):
- Not subject to RIR membership fees (in most cases)
- Fewer transfer restrictions
- May not have formal registration under a specific RIR policy
- Often command premium prices due to flexibility
- Transfer process may differ from standard RIR procedures
Provider Independent (PI) Addresses
PI addresses are assigned directly to end users by an RIR:
- Holder must maintain RIR membership or have a sponsoring LIR
- Can be announced from any network
- Transferable under RIR policy with standard procedures
- Subject to the RIR transfer waiting period
Provider Aggregatable (PA) Addresses
PA addresses are allocated to LIRs/ISPs for assignment to their customers:
- Originally intended to be returned when changing providers
- Transfer involves the LIR that holds the allocation
- May require additional steps compared to PI transfers
- Often available in larger blocks
Which Should You Buy?
For maximum flexibility, Legacy addresses are preferred but typically more expensive. PI addresses offer a good balance of transferability and cost. PA addresses can be excellent value if you understand the additional transfer requirements.
On our marketplace, each listing clearly shows the IP status so you can make an informed decision.