Subnetting class b pdf

Subnetting, therefore, involves dividing the network into smaller portions called. Any address whose first octet is in the range 128 to 191 is a class b address. Free class b subnetting tutorial, how to subnet class b network. You can view cidr values that is the equivalent valueof your subnet mask, address. Below is given all possible combination of class b subnetting. Remember, the first two octets of a class b network is used to represent the network and the last two octets are used to represent the host. Subnetting questions and answers updated daily networking. Fourth segment lan segment2 requires the block size of 64 which is different and lower from current block size. Subnetting basics in chapter 3, tcpip, you learned how to define and find the valid host ranges used in a class a, class b, and class c network address by turning the host bits all off and then all on. Subnetting class b network is much more similar to subnetting class c, the only difference is that when subnetting class b, you will be working on the third octect. In case of subnetting too, the terribly first and last ip address of each subnet is used for subnet number and subnet broadcast ip address severally. Understanding ip addressing 8 subnetting in 1985, rfc 950 defined a standard procedure to support the subnet ting, or division, of a single class a, b, or c network number into smaller pieces.

In a class b address, the first two octets are the network portion, so the class b example in figure 1 has a major network address of 128. Subnetting is the practice of dividing a network into two or more smaller networks. The concept of subnetting was introduced into the ip world in. The class of an ip address is determined solely by the value in the first octet. Subnetting lets you borrow bits from the host and use them to allow for more networks. Used with a class b network, the third and fourth octets are used for subnetting with. Addresses with 127 in the first octet are reserved and. Rfc 950 august 1985 internet standard subnetting procedure address space of a network to be divided into subnets of different sizes, typically one subnet of half the address space and a set of small. If i want to convert the following binary number to decimal i would use the following table. When subnetting, separating the network and host requires a special mechanism called a subnet mask. Unmasking the subnet mask for the ccna exam dummies. Introduction to subnetting how to calculate subnets. The default format for a class b ipv4 address is network.

In this example, i choose a class b ipv4 address with a slash 22 subnet mask to demonstrate answering the following questions. Subnetting a class b network can involve some serious thought. In this article, we will learn how to subnet and make subnetting an easy task. For class a, the total numbers of hosts available are 2 24 2 or. Class b addresses are used for networks that have between 256 and 65534 hosts. Free class a subnetting tutorials, ipv4 address subnetting. For each subnet, you should now be able to determine the subnet size, increment, octet and subnet mask from the.

Class b ip addresses can be subnetted the same way as class a addresses, by borrowing bits from host bits. You can view cidr values that is the equivalent valueof your subnet mask, address numbers that can be used with this subnet mask and wildcard masks. To subnet a network is to create logical divisions of the network. Ipv4 subnetting practice for the ccna class b youtube. Ip address classes class a 1 127 network 127 is reserved for loopback and internal testing leading bit pattern 0 00000000. This lesson explains class b subnetting, ip address subnetting, subnet mask, and how to subnet class b network. Determining new subnet mask your example is a class b address. Here we are borrowing 7 bit for network and 9 bit for host27128 and 29512 so each network having 510 host. In case of class a and b ip addresses, each of them provides for a large number of hosts. Turning on borrowed bits and determining decimal value if you turn on 10 bits, you get the following.

This is accomplished by manipulating the 32bits available in an ipv4 address. Number of hosts per subnet range of network ids first octet. Class b has 16384 214 network addresses and 65534 2162 host addresses. In this lesson, well take a look at what subnetting is and why we use it. Seven steps to subnetting seven steps to subnetting v181104. List your subnets subnet size in order from largest to smallest. By default, using classful networking, fourteen bits are used as network bits providing 2 14 16384 networks and 2 161 65534 hosts. Free class b subnetting tutorial, how to subnet class b. Lets say you are subnetting a class b address with the subnet mask 255. In a class c address, the first three octets are the network. In this class b subnetting tutorial part 1, you will learn how to subnet a class b network. Now, lets take a look at subnetting of class b ip address. Write down the starting ip address as the network address for your largest subnet, which is typically the network address.

Class c the first three octets denote the network address, and the last octet is the host portion. Octets 3 and 4 16 bits are for local subnets and hosts. Instead of using current subnets, lets do subnetting again for this segment. The first bytenumberoctet identifies the class that the ip belongs toclassification correct classification is a starting point, for mastering ip subnetting what we know or should cont. How to calculate subnets northampton community college. This subnet is usually used in pointtopoint link connections e. In a 24 cidr subnet there are a total of 256 host ip addresses but the usable host ips are 2562 254. In a 30 cidr subnet there are total of 4 host ips but the usable host ips are 422. We have already discussed how to create a subnetwork from a single network address. As a network administrator, youll have to know it and know it well. In this subnetting cheat sheet page, you can view all you need about subnetting. Todd lammle walks you through clear instructions and simple. If subnetting is a problem, the 16bit block class c networks, or the 20bit block class b networks of private address space can be used.