1. Web Hosting with SSL – Generally, an SSL certificate will be issued for a specific domain. Because of the limitations of the Apache web server, certificate files are restricted to a per-IP or per-system basis. Therefore, any client that would like to host an SSL encrypted domain on the server will need a unique IP address.
2. Custom Name Server Addresses – In compliance with standard RFCs, each name server must run on two unique IP addresses. In order for resellers and other customers to utilize custom name servers on their own domain, 2 IP addresses are required.
3. Applications Requiring a Unique Port – Some services that clients choose to host require that each instance of the application utilize a specific port on the server. Therefore, to run multiple instances of the service, multiple IP addresses are required. Generally, we will accept justification in the form of a description of the service(s) that are going to be used, the number of addresses that are going to be assigned to each of the clients, and the amount of space that the client has already received from an existing upstream provider. In some cases, we will require additional information. Assignments of space for the purpose of hosting applications that require a unique port are subject to the Slow-Start policy for a request for a /26 block or larger.
4. VPS Hosting – Providers of VPS hosting services require unique IP addresses for each VPS software node that they provide to a customer. Additionally, as a VPS functions much like a dedicated server, end-users and the customer themselves may wish to utilize the service to provide other services that are acceptable justification for additional address space. Any of the services listed above are examples of the services that a VPS customer may host on their VPS server.
5. Network Equipment and IPs used for Addressing – Generally, this type of justification will only apply to co-location customers. Addresses utilized for access and administration of networking devices, such as routers, switches, PDUs, and other equipment, will fall into this category.