Private IPv4 Addressess

IPv4 doesn't provide enough addresses for all devices that need an IP address in the modern world.

The long-term solution is to switch to IPv6.

There are three main short-term solutions:

1. CIDR

2. Private IPv4 addresses

3. NAT

RFC 1918 specifies the following IPv4 address ranges as private:

• 10.0.0.0/8 (10.0.0.0 to 10.255.255.255)

• 172.16.0.0/12 (172.16.0.0 to 172.31.255.255)

• 192.168.0.0/16 (192.168.0.0 to 192.168.255.255)

You are free to use these addresses in your networks. They don't have to be globally unique.