A set of numbers that tells a router which parts of an IP address must be read. In a subnet mask, a binary digit of says "read", and says "don't read". Subnet masks save routers from having to process an entire IP address, which makes routing more efficient. Example: a subnet mask of 255.255.255.0, when translated into binary digits, is: 11111111.11111111.11111111.00000000 This tells a router to look at the first three parts of the IP address and ignore the last part.
See Subnet. When a TCP/IP device tries to communicate with another device, the bits of the TCP/IP destination address are "ANDed" with the subnet mask to determine whether the address is a local address (broadcastable) or must be reached through a router.
A string of binary bits, expressed in octal, that screens Internet address values so the router does not have to look at the entire 32 bit address -- it can simply look at the bits selected by the mask. More information
A 32-bit address mask that is used to specify a particular subnet.
The method used for splitting IP networks into a series of subgroups. The mask is a binary pattern that is matched up with the IP address to turn part of the host ID address field into a field for subnets.
A means of dividing larger IP networks into smaller IP "subnets".
A grouping of bits that determines which bits of the IP address will be used to define a subnetwork. The subnet mask is configured using the NMMGR utility and specified in the same format as an IP address.
Used to mask all or part of an IP address used in a subnet address.
a numeric value that helps a networked host or router understand how to interpret the destination IP address on packets the machine receives
a parameter used in combination with an IP address to inform the clients/servers the size of the local subnet
a special bit pattern that identifies
A set of 4 octets that tells a host what part of an IP address to use for identifying networks and what part to use for identifying hosts.
Your Subnet Mask tells your computer (or other networking device) how many computers are on it's local network. This helps your computer direct traffic locally and out to the Internet. Your Subnet Mask is often given to you with a IP Address, Gateway Address and DNS Addresses. This set of information tells your computer how to find things on the Internet.
A bit template that identifies to the TCP/IP protocol code the bits of the host address that are to be used for routing for specific subnetworks.
A 32-bit value expressed as four decimal numbers from 0 to 255, separated by periods (for example, 255.255.0.0). This number allows TCP/IP to determine the network ID portion of an IP address.
A number used to identify a subnetwork so that an IP address can be shared on a LAN (Local Area Network). | français
Once a packet has arrived at an organization's gateway or connection point with its unique network address, it can be routed within the organization's internal gateways using the host address. The router knows which bits to look at (and which not to look at) by looking at a subnet mask. A mask is simply a screen of numbers that tells you which numbers to look at underneath, specifically an IP address. Using a mask saves the router having to handle the entire 32 bit address; it can simply look at the bits selected by the mask.
Subnetting allocates a portion of the host part of a Class A, B or C Internet address for use as a subnet. A subnet mask is a 32-bit value used to distinguish the combined network and subnet parts of the Internet address from the remaining host part. Bits in a subnet mask set to 1 correspond to the bits in the network portion of the Internet address. Bits in a subnet mask set to 0 correspond to the bits in the host portion of the Internet address. A subnet mask may be specified when a server is initially started up.
An IP address that represents the size of a network. Also see IP address.
A TCP/IP configuration parameter that extracts network and host configuration from an IP address. tag files Files that contain information about files on a Gopher server. This information is sent to clients and it typically contains the file name, host name, and port number.
Under TCP/IP, 32-bit values that allow the recipient of IP packets to distinguish the network ID portion of the IP address from the network ID portion of the IP address from the host ID.
A mask used to separate the network portion of an IP address from the host portion. See network classes.
A value used with an IP address to identify a sub-network. This value is expressed in a form similar to an IP address. For example, 255.255.0.0.
This is used to recognize the sections of an IP address that concur with the different parts. Also known as the "subnet mask".
A 32-bit number to specify which part of an address is the network number, and which part is the host address. When written in binary notation, each bit written as 1 corresponds to 1 bit of network address information. One subnet mask applies to all IP devices on an individual IP network.
A template or filter imposed on an Internet address for the purpose of separating the members of a particular subnetwork. The "1" bits in the subnet mask indicate the significant bit positions in the subnet address; the "0" bits indicate bit positions that are ignored.
The subnet mask specifies the network number portion of an IP address. Your device will compute the subnet mask automatically based on the IP Address that you entered. You do not need to change the computer subnet mask unless you are instructed to do so.
A bit mask that separates the portions of an IP address significant to the network from the bits significant to the subnet. For a class C address, a standard subnet mask is 255.255.255.0, which masks the first three bytes of the address, and leaves the last byte available to identify machines on the subnet.
A 32-bit value that allows the recipient of IP packets to distinguish the network ID portion of the IP address from the host ID.
A 32-bit address mask used in IP to specify a particular subnet. The subnet mask that should currently be used at the Univesrity of Helsinki is 255.255.255.0. This identifies the first three octets as the subnet and the last octet as the host number. For example, with the address 126.96.36.199 and the subnet mask 255.255.255.0, the subnet is 128.135.12. Glossary
A 32-bit address mask used to indicate the number bits of an IP address that are being used to create a subnetwork (or subnet).
A number used to mathematically "mask" or hide the IP addresses on the network by eliminating those parts of the address that are alike for all the machines on the network.
A 32-bit number used to separate the network and host sections of an IP address. A subnet mask subdivides an IP network into smaller pieces.
Subnet mask divides an IP address in two parts: network mask and an address of a host in the network. The mask has the same format as IP addresses (e.g. 255.255.255.0), but it is displayed as a 32-bit number with certain number of left-to-right oriented ones and zeros (mask cannot include other values). Number one in a subnet mask represents a bit of the network address and zero stands for a host's address bit. All hosts within a particular subnet must have identical subnet mask and network part of IP address.
This is a 32bit number that is used by routers to separate that network and host portions of an TCP/IP address.
A 32-bit mask used to interpret the network address from the host addresses in an IP address.
See Address Mask. (8/97)
A part of the internet address that designates a subnet.
Also known as a network mask, it is a bitmask used to tell how many bits in an octet(s) identify the subnetwork, and how many bits provide room for host addresses. Subnet masks are usually represented in the same representation for the addresses themselves; in IPv4, dotted decimal notation, four numbers from 0 to 255 separated by periods, e.g. 255.128.0.0.
An IP address consists of two components, namely the network address and the host address which is used to identify each of the PCs on the network. The subnet mask refers to the bits reserved for the network address plus the bits reserved for the host address. Just like an IP address, it is expressed in the "111.222.333.444" format. Bits other than the network address represent the host address. Dividing the IP address 192.168.0.1 by the subnet mask "255.255.255.0" would give the IP address "192.168.0" and the host address "1".
A model IP address that tells a computer which parts of the IP address are common to all of the machines on the network.
A separate IP address, or part of the host IP address, that determines the part of the host IP address that is its subnet. For example, 192.168.40.0 255.255.255.0 (or 192.168.40.0/24) indicates that the first 24 bits of the IP address are its subnet, 192.168.40. In this way, addresses do not need to be divided strictly along network class lines.
A subnet mask is a term used to indicate how much of an IP address is used to identify the network. An IP address has two parts, the first identifies the network and the second identifies the machine or PC on the network. Also see IP Address Network
A series of ones and zeros much like the IP address that tells your system and all attached systems what network your in and what systems are in the same network. Networking
A set of bits that excludes networks from having a system-wide broadcast, instead of restricting the broadcast to a subnetwork.
A 32–bit mask used to identify the bits in an IP address that correspond to the network address and subnet portions of the address.
Portion of a network. Distinguished from other portions by the use of a mask or subnet number. Subnet masks split one network into a set of mini networks or subnets. Subnetting helps to reduce traffic on each subnet. Subnetting also makes the network more manageable. Each subnet functions as if it were an independent network.
An address code that determines the size of the network.
The part of the address mask that identifies an individual network within a larger network.
This is a portion of a network and is distinguished from other portions by the use of a mask or subnet number.
Typically, a subnet may represent all the machines at one geographic location, in one building, or on the same local area network (LAN). Having an organization's network divided into subnets allows it to be connected to the Internet with a single shared network address. Similar in form to an IP address and typically provided by an ISP. An example of a subnet mask value is 255.255.0.0.
A number that a manager enters to tell the switch how to filter incoming packets. For example, a subnet mask of 255.255.0.0 for the address 188.8.131.52 tells the switch to only accept traffic destined for IP addresses that begin with 192.3. All other packets are dropped.
network setting that indicates the size of the network you're on.
A 32-bit quantity indicating bits in an IP address identify the physical network.
32-bit address mask used in IP to indicate the bits of an IP address that are being used for the subnet address. Sometimes referred to simply as mask. See also address mask and IP address.
A number that splits an IP address into a network number and a computer number. This is like splitting a street address into a street name and a house number
The technique used by the IP protocol to filter messages into a particular network segment (subnet). The subnet mask is a binary pattern that is stored in the client machine, server or router and is matched up with the incoming IP address to determine whether to accept or reject the packet.
A mask that is used in the IP protocol to separate the subnet address from the local IP address. The IP protocol performs a bit-wise AND on the IP address and the subnet mask. Each address segment represents one byte, where 255 converts to FF hex. For example, if the IP address is 192.009.150.184 and the subnet mask is 255.255.255.0, the subnet address is 192.009.150.
A 32-bit value that enables the recipient of IP packets to distinguish the network ID and host ID portions of the IP address. Typically, subnet masks use the format 255.x.x.x.
A number that specifies which bits of the Network ID will be used in a bit-wise AND operation with IP addresses that accompany requests.
See: address mask subnet number
Number of bits of the network address used for the host portion of a Class A, Class B, or Class C IP address.
A configuration feature of a router that is used to select the portion of a 32-bit TCP/IP node address that refers to the LAN and to select the portion that refers to the node on the LAN.