How does it work to get a block of 5 IP addresses?
Technically, it really is a block of 8 addresses, and 5 of those addresses are usable for customer devices. As with any IP subnet, the first and last IP addresses within the subnet cannot be assigned to specific devices. In a static IP address scenario, the DSL router requires one of the usable addresses. Thus you end up with 5 usable addresses from the block of 8. As an example, table 1 provides a detailed breakdown for subnet 63.224.53.0 with a subnet mask of 255.255.255.248 (a “/29” subnet mask).
