Provider-aggregatable address space (PA) is a block of
IP address
An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...
es assigned by a
regional Internet registry
A regional Internet registry (RIR) is an organization that manages the allocation and registration of Internet number resources within a region of the world. Internet number resources include IP addresses and autonomous system (AS) numbers.
...
to an
Internet service provider
An Internet service provider (ISP) is an organization that provides a myriad of services related to accessing, using, managing, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, no ...
which can be
aggregated into a single route advertisement for improved Internet routing efficiency.
Unlike
provider-independent address space
A provider-independent address space (PI) is a block of IP addresses assigned by a regional Internet registry (RIR) directly to an end-user organization. The user must contract with a local Internet registry (LIR) through an Internet service provi ...
, the end-user of address blocks within a provider-supplied space cannot reuse the addresses if they change up-stream connectivity providers.
References
Network addressing
IP addresses
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