Subnet
A subnet is a logical subdivision of an IP network, defined by a prefix length (written as a CIDR suffix like /24) that marks how many of the address's bits identify the network versus the individual host. Subnetting lets an organization split one large address block into smaller, independently routable or administrable segments -- separating a guest Wi-Fi network from internal servers, for example. The same math applies to deciding whether an address falls inside a reserved range, such as checking if a router's WAN address sits inside the 100.64.0.0/10 block ISPs use for CGNAT, or inside the private ranges defined by RFC 1918.
By AdminKit team, Netbase JSC · Updated