What is a Subnet mask ?

Answer 1

dude seriously stop it, just usse wikipedia, its a network address that distribes what "subnet you're on" used for routers with mutiple subnets.

default subnet mask is 255.255.255.0 on a standard class C network.

Answer 2

A mask used to determine what subnet an IP address belongs to. An IP address has two components, the network address and the host address. For example, the IP address 150.215.017.009 - the first two numbers (150.215) represent the network address, and the second two numbers (017.009) identify a particular host on this network. Subnetting enables the network administrator to further divide the host part of the address into two or more subnets. The subnet mask is the network address plus the bits reserved for identifying the subnetwork. It usually looks like this 255.255.220.0 but can be anything, it depends on the network.

Answer 3

Stupidboy you are not stupid here is your answer

1 The subnet mask is used to determine where the network number in an IP address ends and the node number in an IP address begins. A node is anything on a network that needs an IP address to communicate (a PC, server, router, etc).

2 A mask used to determine what subnet an IP address belongs to. An IP address has two components, the network address and the host address. For example, consider the IP address 150.215.017.009. Assuming this is part of a Class B network, the first two numbers (150.215) represent the Class B network address, and the second two numbers (017.009) identify a particular host on this network.

3 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.

4 A model IP address that tells a computer which parts of the IP address are common to all of the machines on the network.

5 IP network addresses are given in the form (or, if subnetted, ) when viewed in binary notation. Masks determine how much of the address is network, and how much host.

6 A local bit mask (set of flags) that specifies which bits of the IP address specify a particular IP network or a host within a subnetwork. An IP address of 128.66.12.1 with a subnet mask of 255.255.255.0 specifies host 1 on subnet 128.66.12.0. The subnet mask determines the maximum number of hosts on a subnetwork.

6 This feature partitions the network into segments. It is the way a router knows if a packet sent stays on the local network or needs to be passed to a different network.

7 The method used for splitting IP networks into a series of subgroups or subnets. 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.

8 A 32-bit value that is used to distinguish the network ID portion of the IP address from the host ID.

9 A 32-bit binary number IP uses to compare two IP addresses to determine whether the hosts bearing those addresses are on the same network. An administrator divides one network into two or more subnets by assigning a subnet mask.

10 The word subnetwork has two related meanings. In the older and more general meaning, it meant one physical network of an internet.In the Internet Protocol, a subnetwork, usually known as a subnet, is a division of a computer network.

Answer 4

It's a binary structure which separates the NETWORK portion of an IP address from the NODE portion of an IP address.

It's called a MASK... because not unlike a MASK in real life, you use it to cover certain portions of the address and allow other s to show through. (like your eyes and sometimes mouth)...

In binary... you put a one in any BIT of the IP ADDRESS you want to be the network. That Bit pattern is then expressed in HEX or DECIMAL All ones for all 8 bits of the octet would be 255.

If you have (what we call) a Class C address, the one where the first 3 octets are NETWORK designation the mask would be:
255.255.255.0.

That would provide you the maximum number of networks and up to approx 250 nodes on that network.

I could go on for hours explaining the derivation and showing ANDING and how the IP STANDARD actually uses the mask... Feel free to email me if I've not covered the basics in my explanation, that you need.

Answer 5

a subnet mask is used i networks.subnet mask contains two parts.namely network id and host id.first two parts of ur subnet mask is network id and last two parts are host id.suppose if u r having a small office or organisation say about 50 computers u can go for a subnet mask like 255.255.255.0.by this u can vary ur ip address with one range.for example....192.168.5.1, 192.168.5.2, 192.168.5.3 etc
if u go for 255.255.0.0 then u can assign ip addresses in the following range.....192.168.5.1, 192.168.4.3 etc.if u in a class c network go for 255.255.255.0.if u r in a class b network go for 255.255.0.0

Answer 6

a subnet mask is a screen of numbers which tells you which numbers to look at underneath in a binary mask.

Answer 7

a mask worn by network people that live in the subterranean world

Answer 8

ITS MINE

Answer 9

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