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. The justification will be considered Acceptable when the customer provides a copy of the CSR and corresponding CAsigned CRT for each domain. Please do not include the key file.
2. Custom Name Server Addresses: In compliance with standard RFCs, name servers must run on 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. Examples of these types of services include SMTP, POP, IMAP4 and NNTP.
4. Virtual Machine Hosting: Providers of virtual machine hosting services require unique IP addresses for each virtual machine that they provide to a customer. Additionally, as a virtual machine functions much like a dedicated server, endusers as well as the customer 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 virtual machine hosting customer may host on their virtual machine hosting 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.