What is RFC 1918

1. RFC 1918 (Request for Comment 1918) is a standard established by the Internet Engineering Task Force (IETF) that defines specific IP address ranges to be used exclusively within private networks.

2. These addresses are not routable on the public Internet, meaning devices using them cannot be reached directly from outside their local network. Routers on the Internet are configured to discard packets with these addresses, ensuring they remain confined to private networks.

3. RFC 1918 helps conserve IPv4 addresses by designating specific IP address ranges for private use within internal networks.

4. Devices using these private addresses can communicate within their local network without requiring globally unique (public) IP addresses, which are limited in number.

5. This means organizations and households can assign the same private IP ranges (such as 10.0.0.0/16, 172.16.0.0/12, or 192.168.0.0/16) to their internal devices, reusing the same addresses across different networks without conflict.

Purpose and Motivation:

• RFC 1918 was introduced as a solution to IPv4 address exhaustion.
• By allowing organizations to reuse these address blocks internally, it greatly expanded the number of devices that could be connected to networks without requiring globally unique (public) IP addresses.

These addresses enhance security by isolating internal network devices from direct Internet exposure.