Why is 30 the smallest subnet?

What is a 30 IP range?

I am trying to understand how a 30 IP range will be allocated to one organization.

We have 2 different organizations that are using the same server as us. I read that we have to purchase a 30 IP range which is shared between the two organizations.

But I am not able to understand how is it shared between the two organizations. Will each organization get 10 IP addresses from the 30 IP range? Or is it possible to get only 5 IP addresses from the 30 IP range, and 10 IP addresses from the 30 IP range? Thanks in advance. IP address allocation is normally per organization - but not always. It is not unusual to purchase a block of IP addresses from your ISP (eg 10.0/24), which can then be used for multiple organizations.

This is especially common when you have a private cloud with a public facing network, which is the case for many organizations. For example, Google provides free public IP addresses to organizations which sign up for their public cloud offering.

What is 31 or 30 subnet?

A subnet is a logical group of IP addresses that you can think of as one "network".

In this case, it means the network of the 31st and 32nd IP addresses.

When you want to communicate with "the net" you do it from within a subnet. For example, if you want to communicate with IP address 32.4.10.20:

You need to send the packet to the internet. The router (or gateway) between the subnet and "the internet" knows how to route the packet back to you.

The router then forwards the packet to its "next hop", or the next gateway toward the destination. That gateway needs to forward the packet to its next hop until it reaches the destination. The IP address of the last gateway to pass the packet to the final destination is the address for which you need to know the subnet.