These networks use the 255.255.255.0 subnet mask, or /24 CIDR notation. The starting host address is 192.0.0.0 and the ending address is 223.255.255.0. These networks use the 255.255.0.0 subnet mask, or /16 CIDR notation.Ĭlass C: Allows 2 8 host addresses on the network.

The starting host address is 128.0.0.0 and the ending address is 191.255.0.0. Tip: To work out the last host address, fill the host portion with binary. These networks use the 255.0.0.0 subnet mask, or /8 CIDR notation.Ĭlass B: Allows 2 16 host addresses on the network. Netmask Range of addressesAn IP Subnet Calculator is a tool that may be used. The starting host address is 0.0.0.0 and the ending address is 127.0.0.0. Specific size details are defined in the following class definitions:Ĭlass A: Allows 2 24 host addresses on the network. Network classes define how many addresses are allowed on the network, with class A being the largest and class C being the smallest. The above table uses Class A, B, and C to define network types. This means that the last 8 bits of the IP address are reserved for host IP addresses, thus IP addresses 192.168.0.15 through 192.168.0.255 will be allowed as host IP addresses on the network. The whole point is to represent in bits which bits are the. This means that the first 24 bits of the IP address are reserved for network routing. Because you need more than 5 bits to cover a 32-bit integer such as an IP address. 192.168.0.15 defines the address prefix, and /24 defines the number of bits reserved for the netmask. To understand what CIDR notation means, take the IP address 192.168.0.15 and the /24 CIDR, for example.

CIDR accomplishes the same task as traditional subnet masking. It enables network administrators to group blocks of IP addresses into single routing networks. The following table details how many networks and IP addresses are allowed with each CIDR length and equivalent subnet masks.ĬIDR stands for Classlesss Inter-Domain Routing. CIDR defines which IP addresses, and how many host IP addresses will be allowed on the network. CIDR notation accomplishes the same task as network subnet masking.

5 ip subnet mask