Which subnet does the following ip belong to

So, let's get started. IP version 4 is 32 bits long. So, the maximum number of IPv4 addresses is 4,,, addresses i. It consists of four octets each of which can contain one to three digits ranging from 0 to separated by a single dot.

Here, each number is the decimal representation base for an 8 digit binary number base Some bits of the IP address represents the network and the remaining bits represent the host. The IP address can be further be divided into two parts:. Network ID: It identifies which network you are on. The number of networks in any class is given by the formula:.

Host ID: It identifies your machine on the network. The number of hosts in any class is given by the formula:. This second method is used with CIDR. For example, The network subnetting scheme in this section allows for eight subnets, and the network might appear as:. Notice that each of the routers in Figure 2 is attached to four subnetworks, one subnetwork is common to both routers.

Also, each router has an IP address for each subnetwork to which it is attached. Each subnetwork could potentially support up to 30 host addresses. This brings up an interesting point. The more host bits you use for a subnet mask, the more subnets you have available. However, the more subnets available, the less host addresses available per subnet.

For example, a Class C network of If you use a mask of Since you now have four bits to make subnets with, you only have four bits left for host addresses. So in this case you can have up to 16 subnets, each of which can have up to 16 host addresses 14 of which can be assigned to devices. Take a look at how a Class B network might be subnetted. If you have network Extending the mask to anything beyond You can quickly see that you have the ability to create a lot more subnets than with the Class C network.

You use five bits from the original host bits for subnets. This allows you to have 32 subnets 2 5. After using the five bits for subnetting, you are left with 11 bits for host addresses. This allows each subnet so have host addresses 2 11 , of which could be assigned to devices. Note : In the past, there were limitations to the use of a subnet 0 all subnet bits are set to zero and all ones subnet all subnet bits set to one. Some devices would not allow the use of these subnets.

Cisco Systems devices allow the use of these subnets when the ip subnet zero command is configured. Now that you have an understanding of subnetting, put this knowledge to use. Your task is to determine if these devices are on the same subnet or different subnets.

You can use the address and mask of each device in order to determine to which subnet each address belongs. Looking at the address bits that have a corresponding mask bit set to one, and setting all the other address bits to zero this is equivalent to performing a logical "AND" between the mask and address , shows you to which subnet this address belongs.

In this case, DeviceA belongs to subnet Given the Class C network of Looking at the network shown in Figure 3 , you can see that you are required to create five subnets. The largest subnet must support 28 host addresses. Is this possible with a Class C network? And if so, then how? You can start by looking at the subnet requirement. In order to create the five needed subnets you would need to use three bits from the Class C host bits. Two bits would only allow you four subnets 2 2. Since you need three subnet bits, that leaves you with five bits for the host portion of the address.

How many hosts does this support? The device called a gateway or default gateway connects local devices to other networks. This means that when a local device wants to send information to a device at an IP address on another network, it first sends its packets to the gateway, which then forwards the data on to its destination outside of the local network.

A subnet mask is a bit number created by setting host bits to all 0s and setting network bits to all 1s. In this way, the subnet mask separates the IP address into the network and host addresses. Neither can be assigned to hosts, as they are reserved for these special purposes. The IP address, subnet mask and gateway or router comprise an underlying structure—the Internet Protocol—that most networks use to facilitate inter-device communication.

When organizations need additional subnetworking, subnetting divides the host element of the IP address further into a subnet. The goal of subnet masks are simply to enable the subnetting process. A bit IP address uniquely identifies a single device on an IP network. The 32 binary bits are divided into the host and network sections by the subnet mask but they are also broken into four 8-bit octets. Because binary is challenging, we convert each octet so they are expressed in dot decimal.

This results in the characteristic dotted decimal format for IP addresses—for example, Remember, again, that binary host addresses with all ones or all zeros are invalid, so you can't use addresses with the last octet of 0, 63, 64, , , , , or You can see how it works by looking at two host addresses, If you used the default Class C subnet mask of However, if you use the subnet mask of The result of this comparison tells the computer whether the destination is a local host or a remote host.

If the result of this process determines the destination to be a local host, then the computer will send the packet on the local subnet. It's then the responsibility of the router to forward the packet to the correct subnet. Incorrect Subnet Mask: If a network uses a subnet mask other than the default mask for its address class, and a client is still configured with the default subnet mask for the address class, communication will fail to some nearby networks but not to distant ones.

As an example, if you create four subnets such as in the subnetting example but use the incorrect subnet mask of In this situation, packets destined for hosts on different physical networks that are part of the same Class C address won't be sent to a default gateway for delivery. A common symptom of this issue is when a computer can communicate with hosts that are on its local network and can talk to all remote networks except those networks that are nearby and have the same class A, B, or C address.

Incorrect IP Address: If you put computers with IP addresses that should be on separate subnets on a local network with each other, they won't be able to communicate. They'll try to send packets to each other through a router that can't forward them correctly. A symptom of this problem is a computer that can talk to hosts on remote networks, but can't communicate with some or all computers on their local network.

To correct this problem, make sure all computers on the same physical network have IP addresses on the same IP subnet. If you run out of IP addresses on a single network segment, there are solutions that go beyond the scope of this article.

Incorrect Default Gateway: A computer configured with an incorrect default gateway can communicate with hosts on its own network segment. But it will fail to communicate with hosts on some or all remote networks. A host can communicate with some remote networks but not others if the following conditions are true:. Internet--The global collection of networks that are connected together and share a common range of IP addresses.

Network--There are two uses of the term network in this article. One is a group of computers on a single physical network segment. The other is an IP network address range that is allocated by a system administrator. Octet--An 8-bit number, 4 of which comprise a bit IP address.

They have a range of that correspond to the decimal values Wide area network WAN --A large network that is a collection of smaller networks separated by routers. The Internet is an example of a large WAN. Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services. Privacy policy. Skip to main content.