IP addresses are identifiers for network devices (in general, including computers and any other device that can either accept, send or pass through network data). There are several means to indicate a subnet (or network), several IP addresses logically united in single group.
Typical methods to note a host or network IP address(es) are:
- Host IP address: 192.168.1.102
- IP address range: 192.168.1.1-192.168.2.255, meaning that every IP with each octet included within the ranges listed is part of subnet
- IP address range with mask: 192.168.1.*, where asterisk means “any number of valid address digits”
- Network address notation with mask: 192.168.1.0/255.255.255.0, meaning that IP is part of subnet if after applying the mask (logical AND) the result matches network address
- CIDR (Classless Inter-Domain Routing): 192.168.1.0/24, meaning that all addresses with first 24 bits from the specified IP are included into subnet
Similar method of indicating subnets is used in case of IPv6. Note that in typical network 2 addresses are not available for assignment to devices: the last one in the range is broadcast address, and the first one is so called network address.