Network administrators are faced with a great challenge while selecting the Public IP address space to be used on newly provisioned Internet link. The IP address space has to be one of the following – (1) Provider Aggregatable or (2) Provider Independent.
Just to set the platform, PI (Provider Aggregatable) addresses are individually assigned, do not have a specific provider relation and are always routed independently on the global Internet by themselves as a separate block.
PA (Provider Aggregatable) address assignments made by a Provider and come from a large block allocated to a Provider by RIPE.
While designing, an experienced mind can be life saver because the IP address space selection will depend on many factors like –
- Internet failover scenarios (Multihoming)
- Web facing and Internet browsing application requirements
- Internet Link Failover approach.
Below differences between Provider Aggregatable IP Block and Provider Independent IP block will help give insight how both differ –