What is Subnetting ?

[Asuman]

Hello Friends

I would like to know what is subnetting? I would also like to know are the valid sub net ip address and how can we do it? Does any one have any idea about it? Kindly reply for this issue. Would like to appreciated your views.

Thank you.

[Milton.J]

Subnetting an IP Network can be done for a variety of reasons, including organization, use of different physical media (such as Ethernet, FDDI, WAN, etc.), preservation of address space, and security. The most common reason is to control network traffic. In an Ethernet network, all nodes on a segment see all the packets transmitted by all the other nodes on that segment. Performance can be adversely affected under heavy traffic loads, due to collisions and the resulting retransmissions. A router is used to connect IP networks to minimize the amount of traffic each segment must receive.

[Spyrus]

To get the network and node parts of an address, we apply subnet mask to an IP address. 1 represents to network bit and 0 represents to node bit. To get the network address, we apply an operation among the IP address and the subnet mask is known as Bitwise Logical.

Super-netting is also known as Classes Inter-Domain Routing. The way through which multiple internet addresses of a class are combined together is known as Super-netting. Suppose we have two network addresses. One is 192.168.3.0/18 and other is 192.168.4.0/18. By using Super-netting, we can combine these two addresses into a single address as 192.168.3.0/17. Here seventeen (17) is showing that first 17 bits are representing the network part of address (192.168.3.0/17). There are some protocols which are used Super-netting including BGP and OSPF. Here BGP is known as Border Gateway Protocol and OSPF is known as Open Shortest Path First and it a s routing protocol.

[Shen]

This can be used in the following ways.

• Address—The unique number ID assigned to one host or interface in a network.
• Subnet—A portion of a network sharing a particular subnet address.
• Subnet mask—A 32-bit combination used to describe which portion of an address refers to the subnet and which part refers to the host.
• Interface—A network connection.

If you have already received your legitimate address(es) from the Internet Network Information Center (InterNIC), you are ready to begin. If you do not plan to connect to the Internet, Cisco strongly suggests that you use reserved addresses.

[Steve123]

Subnetting is a network design strategy that segregates a larger network into smaller components. While connected through the larger network, each subnetwork or subnet functions with a unique IP address. All systems that are assigned to a particular subnet will share values that are common for both the subnet and for the network as a whole.