These hosts might be used as routers between subnets, or might simply have more than one LAN interface for purposes of improving throughput. In this case, count each interface. This separation is normally undertaken through a an IP router. A. Simply put, because that's what our address allocation sources require. They need forecasts from us, so we need forecasts from you.
Modern routers can only hold so many routes to different networks.
This implies that routes be aggregated as much as possible. That's why your forecasts need to be accurate. A. Because Class C space is virtually exhausted. If we don't get network allocations within Class C space, we haven't got it to offer to our customers. There's a lot of room for misunderstanding when we're asked this question.