netmask

listen to the pronunciation of netmask
الإنجليزية - الإنجليزية
A netmask is a set of four number blocks separated by periods Each number is normally represented as the decimal equivalent of an eight-bit binary number, which means that each number may take any value between 0 (all eight bits cleared) and 255 (all eight bits set) Every IP address consist of two parts (the network address and the host number) The netmask is used to determine the size of these two parts The positions of the bits that are set in the netmask are considered to represent the space reserved for the network address, while the bits that are cleared are considered to represent the space set aside for the host number
A netmask is a series of bits designed to "mask" certain portions of an IP address The standard netmask for a class C network is 255 255 255 0 - basically the last octet, 0, says "look here for the machine number, the rest (255) is network number " The primary use for netmasks is in subnetting Back to Top
network mask: the network part of an IP address; cf variable length subnet mask
An addressing scheme that creates a logical grouping of a subset of systems on your network
The network mask
used to divide an organization's network as necessary, creating additional destinations for routing purposes Also called a subnet mask or address mask Computers on the various subnets at a given site all appear to the rest of the Internet to be on a single network
A number that explains which part of an IP address comprises the network address and which part is the host address on that network It can be expressed in dotted-decimal notation or as a number appended to the IP address For example, a 28-bit mask starting from the MSB can be shown as 255 255 255 192 or as /28 appended to the IP address
A netmask is binary number that consists of a string of 1s followed by a string of 0s The line between the 1s and 0s is applied to an IP address of a router to define what addresses are on the subnet, below the router, and which ones need to be passed to the higher net above it Typical netmasks look like 255 255 255 0 meaning "IP addresses that are the same as mine in the last 8 bits are on the local subnet, and I don't have to pass them on to the network above me IP addresses that are different than mine in any of the first 24 bits must be passed on " If routers could talk, of course See subnet, too