How To Calculate Subnet Mask From Ip Address Pdf

All Class C addresses have a one in the first bit, a one in the second bit and a zero in the third bit. Routing protocols must base their routing decisions on a 32-bit IP address and a prefix length that can be up to 32 bits. Subnet: A separate and identifiable portion of an organization's network, typically arranged on one floor, building or geographical location. Log in Join now Secondary School. By using VLSM, the administrator can subnet the IP subnet in such a way that least number of IP addresses are wasted. It is also intended to be a teaching tool and presents the subnetting results as easy-to-understand binary values. The subnet mask is used to allow computers to determine whether the addresses of other computers they wish to communicate with are on the local network or on a remote network. The functions and classes in this module make it straightforward to handle various tasks related to IP addresses, including checking whether or not two hosts are on the same subnet, iterating over all hosts in a particular subnet, checking whether or not a string represents a valid. Subnet Calculator. 00000011 Subnet Mask: 11111111. IPv6 Subnet Cheat Sheet. That is unambiguous with respect to the IP addresses 16. 144 is the IP address of the host • 255. I just used an old yahoo address and got right in. An IP address is made up of two components, a network address and a host address. I've now changed it to work with bash and included a few other IP/CIDR/Subnet mask related functions. Route Summarization Operation in Cisco Routers. A client uses the self-configured IP address until a DHCP server becomes available. Total Number of ip addresses are = 100 + 2 = 102 Then the number of unmask bits should be 7 : 2^unMaskBits : 2^7 : 128 Number of Subnet Mask bits ( 16 - 7 = 9) Mask : 16 SubnetMask : 25 (16+9) 172. Subnet Mask. This method starts with the decimal value of the relevant subnet mask byte - 192 in this case. You still are using the default mask for your IP network 192. Determining the Subnet Mask. Subnet masks can be 0, 128, 192, 224, 240, 248, 252, 254 and 255. Simplified IP Subnetting without a Subnet Calculator learn how to subnet in your head without a subnet calculator. 0; Twenty-four bits (three octets) reserved for network identity; Eight bits (one octet) reserved for nodes; Subnet identity based on subnet mask (first address): 192. Learn fundamentals of IP address and Subnet mask. 0 and will end at 172. Let's take an IP address of 10. entire planet. How does a host initiate requests for DHCP?. Each octet is converted to decimal and separated by a period (dot). 13 points How to calculate. The Broadcast Address is obtained doing a binary OR between the Subnet Address and the inverted Subnet Mask (see "Binary Operators"). convert IP addresses and subnet masks from their decimal form to the binary for m because the locations of the 1s and If we use the sample IP address from before, 172. An IP address has two components, the network address and the host address. Each section of the subnet mask can contain a number from 0 to 255, just like an IP address. Subnetting Basics Identifying Subnet Bits in a Class C IP AddressExample: 192. Knowing how to calculate network and broadcast addresses if you have the IP address and subnet mask is essential to setting up a network. For your computer to determine the network and subnet portion of an IP address it must "AND" the IP address with the subnet mask. Default subnet masks Every IP address must be accompanied by a subnet mask. Binary AND determines a network range. 248 has exactly 6 valid host IP addresses. Both of these parts are calculated by the IP address and the number of mask bits. Let's do calculation for IP address 112. 0, then the network address is 192. Ipcalc actually does a lot more - it takes an IP address and netmask and provides the resulting broadcast, network, Cisco wildcard mask, and host range. In addition to the sc0 interface IP address, the switch can obtain the subnet mask, broadcast address, default gateway address, and other information. The calculate subnet mask from ip address is designed to perform the same functions. Linux - IP subnet calculation with ipcalc ipcalc is a program to perform simple manipulation of IP addresses and is useful for calculating various network masks given an IP address. ipcalc takes an IP address and netmask and calculates the resulting broadcast, network, Cisco wildcard mask, and host range. • If a binary bit is set to a 0 (or off) in a subnet mask, the corresponding bit in the address identifies the host. 00000000 The first 16 bits of the subnet mask are set to 1. Get details about the defined IP address and subnet mask. If you're dealing with classfull IP addresses, you look at the first octet value of the address. You can use the IP Address Calculator at work or in school to determine quickly how to subnet an IP network address using a given 32-bit mask for IPv4 or 128-bit prefix length for IPv6. mask provided. The broadcast IP address for the subnet 172. Hence, Broadcast Address for Marketing subnet is 192. The ability to calculate subnets is the most important skill for success in the Cisco CCNA. Gain solid understanding of Default Gateway. Subnetting example. CIDR stands for Classless Inter-Domain Routing. If you are going to set up a network, then you have to know how to distribute the devices on that network. Subnet Cheat Sheet. 10 with a mask 255. Read more Courseware for Intro to Basic Networking. IPv4 Netmask and Subnet Mask Table. Enter IP address and netmask (decimal separated by dots (e. With the help of the network address you can then calculate whether two IP addresses are in the same subnet (simply by comparing the two network addresses). When subnetting, separating the network and host requires a special mechanism called a subnet mask. By giving a second netmask, you can design subnets and supernets. Subnetting made easy If workings things out in binary is too time consuming or that understanding the process in laying things out in 1's and 0's is too tough… try a shortcut! Figure out the magic number from the subnet mask, and find the range of that the IP address resides on. with 8 subnets. The 32 binary bits are broken into four octets (1 octet = 8 bits). • Subnet masks cannot contain all 0s or all 1s in either the host portion or the network portion of the address. IP subnetting is an important skill for any network professional. The bits are applied to the address from left to right. It is also intended to be a teaching tool and presents the subnetting results as easy-to-understand binary values. Subnetting a Class B address is exactly the same as subnetting a class C address, except for the one minor insignificant difference that classes B and C have different default subnet masks. This calculator works with both IPv4 and IPv6 subnets. You have to enter the IP Address and Subnet Mask, and this tool instantly calculates the required information for your use. convert IP addresses and subnet masks from their decimal form to the binary for m because the locations of the 1s and If we use the sample IP address from before, 172. c) Verify the configuration. For example, what happens when you use this mask with a Class B. The same approach applied to a /31 subnet with only two possible addresses in the host identifier would leave no usable addresses for host assignment. The subnet mask for one bit subnetting is 255. Results of the subnet calculation provide the hexadecimal IP address, the wildcard mask, for use with ACL (Access Control Lists), subnet ID, broadcast address, the subnet address range for the resulting subnet network and a subnet bitmap. The ability to calculate subnets is the most important skill for success in the Cisco CCNA. This is so because the default subnet mask for a class A IP address is 8 bits (or, written in dotted decimal notation, 255. 158 /2815810 = 1001 11102Step 2: Examine the host octet by converting it to a binarynumber. 255 are reserved for loopback interfaces – Most systems use 127. The way that we calculate the end is with addition, just raw addition. b) Configure two Cisco Routers and PCs according to your subnetting scheme. and subnet 10. Subnet Masks - How Subnet Masks. x when configuring addresses and networks. It is a tool for calculating the subnets. About a year ago I was looking for a way to get all active ip-addresses on subnet. and you need 1100 hosts. One subnet for 24 hosts. Generates a subnet plan with useful information, such as subnet address, subnet mask, host address range and broadcast address. How to Subset a Class C Address Using the Binary Method It can be helpful to know how to be your own subnet mask calculator. 0 and divide (Great Divide) the from the rest. Just be sure that the last octect is a multiple of 4: i. Hello Again all, I wonder if someone can advise if there is a simple way of getting the Mask Bits and Subnet ID. While doing further calculation, Starting IP address for Next (IT) subnet is next IP to Broadcast Address of Previous (Marketing) subnet. How to calculate subnet mask from ip address manually? - 3273872 1. Classful and classless subnet calculator. You can also use it as a teaching tool to present subnetting results in an easy to understand binary values. 00000011 Subnet Mask: 11111111. In IP subnetting, it is important that we know how to convert IP addresses and subnet masks from their decimal form to the binary form because the locations of the 1s and 0s is extremely important. For example, we can have subnet 16. Create a custom subnet mask for the entire network –Accomplished by moving the Line to the right (increasing the bits that are “on” in the mask. To get 4 addresses out of any block, use a /30 CIDR or 255. We get this information by converting the decimal numbers within the subnet mask to binary. If the client is unable to find the information, it uses APIPA to automatically configure itself with an IP address. Standard syntax for writing IP addresses with a routing prefix. Returns true if the IPEndPoint supplied is on the same subnet as this host: 25. Network Bits Subnet Bits Usable IPs First Usable IP Last Usable IP Broadcast. This method starts with the decimal value of the relevant subnet mask byte - 192 in this case. We are going to subnet it to three different networks with equal host IP addresses; remember we are working on the THIRD octect with the block size of 16. It is also intended to be a teaching tool and presents the subnetting results as easy-to-understand binary values. Enter the information in the IP address field below. Subnet Masks. Note that this combination of IP addresses and subnet masks in the charts are written as two separate values, such as Network Address = 205. A subnet mask, which contains a binary bit pattern of ones and zeros, is applied to an address to extract the. Here's an example:. 0, then select Optional Mask from dropdown. The Subnet Calculator tool can be used to determine subnetted IP address ranges given desired input parameters. 0/16 into 4 equal sized subnets. Example: IP Address 192. Answers to Subnetting and Creating Custom Subnet Masks Practice Problems Answers assume Non-RFC 1812 networks (must subtract 2 from the number of Host IDs). I need test data for a IP Subnet calculator I have developed. You are tasked with Subnetting the Address to get the most networks with at least 30 Hosts per Subnet. Need for a IPv6 subnet calculator. xxx) or hostname: 23. IP addresses of this type starts with a number between 128 and 191. The range of IP addresses possible on the network and the broadcast address of that network can also be identified. docx Page 4 of 4 Step 4: Turning on Borrowed Bits and Determining Decimal Value If you turn on 10 bits, you get the following: 11111111. A common subnet mask for a Class C IP address is 255. Subnet mask is a mask used to determine what subnet an IP address belongs to. (/23) used with a Class A address means that there are 15 subnet bits and 9 host bits. 1 (which gets expanded to 192. 1, we will write all numbers in binary form to reveal what a computer really sees in an IP address. Learn what VLSM (Variable Length Subnet Masks) Subnetting is and how it is done step by step including the advantages of VLSM Subnetting and the differences between FLSM Subnetting and VLSM Subnetting. An example will help you understand the subnetting concept. In binary form the mask is: 11111111. docx Page 4 of 4 Step 4: Turning on Borrowed Bits and Determining Decimal Value If you turn on 10 bits, you get the following: 11111111. Not much is the same with IPv6 compared to IPv4. Need for a IPv4 subnet calculator. A subnet mask is used by a router to learn which of the bits in an address refer to the subnet and which bits refer to the host. The network portion of a device’s IP address determines what. The following subnet cheat sheet will not solve all of the subnetting questions on the exam. There was a problem previewing this document. 0/24, the following five IP addresses are reserved:. We now know the IP address: 192. Solved examples with detailed answer description, explanation are given and it would be easy to understand - Page 2. Refer to the following Table CIDR Subnet Table : to find the CIDR equivalent of a decimal subnet mask. Using the binary math required to find the subnet number and broadcast address really does help you understand subnetting to some degree. The subnet mask is what actually will do all of the work of subnetting (read again, subnet mask). Results of the subnet calculation provide the hexadecimal IP address, the wildcard mask, for use with ACL (Access Control Lists), subnet ID, broadcast address, the subnet address range for the resulting subnet network and a subnet bitmap. Binary AND determines a network range. Summary Below is a table specifying the various netmasks that can be used. To use the calculate subnet mask from ip address you need to use the instruction or contact the professionals. Initially the network mask is shown according to IP ADDRESS Class for calculations of classful networks. Understanding Classful Network Mask explains why every Network IP device must belong to a Network Address, and how every Network Address must have Netmask Address. For example, if you IP is 192. For classless supernetting, please use the CIDR Calculator. 0 (also written 150. -> Quick Store: Used to quickly store the information in the storage table. ipaddress provides the capabilities to create, manipulate and operate on IPv4 and IPv6 addresses and networks. ** Inverse mask is calculated by subtracting each subnet mask octet value from 255. Here are some of the powerful features of the CertificationKits CCNA Subnet Calculator: Classful Subnet Calculator – This can create your subnet results based on many different options such as: subnet mask, mask bits, most bits, number of subnets and hosts per subnet and then it gives you the ability to export all this data and more. Class D and Class E addresses also have their specified bit arrangement. and that 172. See MAC Address in action. Subnet mask divides the IP address into a network address and host address, hence to identify which part of IP address is reserved for the network and which part is available for host use. Both of these parts are calculated by the IP address and the number of mask bits. Routing tables used by IP are prepared using routing protocols like OSPF, BGP. Class B Networks. 255 is the broadcast IP address of the 172. It has been a while since i post i was really busy with so many stuff, bottom line, i had this strange requirement at work where i had to create a script to calculate the IP address from a subnet, now normally this means we have to create a bunch of scopes or subnets in the DHCP server, which was my case, i had to create more than 4 thousand scopes on Linux DHCP server. address is which. Trademarks: Wiley, For Dummies, the Dummies Man logo, Dummies. Hence the IP Address starts from 192, it indicates it is a Class C address. Unlike IPv4, an IPv6 address has a dedicated subnetting portion. IP Custom Subnet Masks (Page 4 of 4) Subtracting Two From the Number of Hosts Per Subnet and (Possibly) Subnets Per Network. The wildcard mask of /12 is: 255. To quickly calculate the size of the subnet you can use the following trick:. A subnet mask is a way of telling your computer or router what network addresses it can consider local and which are remote. How to determine hosts, networks and subnets; Step 4: Subnetting backwards Tutorial on reverse calculation of the subnet mask. Enter the information in the IP address field below. The subnet mask field can be expressed in bits or as octets. Learn IP Addressing and Subnetting from scratch this course and gain solid understanding of all networking concepts. To better understand how IP addresses and subnet masks work, look at an IP (Internet Protocol) address and see how it is organized. Get details about the defined IP address and subnet mask. Variable Length Subnet Mask Îallows more than one subnet mask in the same network ÖA) more efficient use of organization’s IP address space ÆSubnets may significantly vary in relative size (computer room = 200 hosts, secretary = 4 hosts…) Æconsider a 4 host network with mask 255. Variable Length Subnet Masking "VLSM" is a technique that allows network administrators to divide an IP address space into subnets of different sizes, unlike simple same-size Subnetting. Click once on the field of subnet mask and delete the old subnet mask, then configured the new subnet mask and click on OK tab and then click OK. The instruction is attached to the mask upon receipt. How to Calculate Subnets Subnets and Hosts Borrow 2 bits S S H H H H H H # of subnets = 22 =. Thank you for visiting SubnettingPractice. , Range is 10. By using VLSM, the administrator can subnet the IP subnet in such a way that least number of IP addresses are wasted. It consists of an IP address, a slash, then a number of bits to measure the routing prefix. WMIC is a command-line tool and that can generate information about computer model, its manufacturer, its username and other informations depending on the parameters provided. Now i will explain how to change these addresses if needed. The subnet 192. Random IP addresses from the subnet. UInt32 To IP Address: 21. An IP address is divided into two parts: network and host parts. We knew how to get the IP address, subnet mask and gateway details of Linux server. Accordingly, one may think that the subnet ID is 172. Variable-Length Subnet Masks (VLSM) This page discusses VLSMs and how they can be used to further maximize IPv4 addressing efficiency. A common example of a subnet mask for class C IP addresses is 255. The results will appear in the fields located to your right side. Hi Ianne, Here is one way to calculate it. ipcalc takes an IP address and netmask and calculates the resulting broadcast, network, Cisco wildcard mask, and host range. 0/16 into 4 equal sized subnets. ANDing the mask and addresses shows clearly which subnet the IP-address belongs to: addresses 1 and 3 belong to the subnet starting at (1000 0000) or. VLSM allows an organization to use more than one subnet mask within the same network address space. Docx Page 1 of 2 IP Addressing and Subnetting Reference Table (table to be completed during break-out) Address Class First octet value range First binary bits Number of Default Network Bits Default Subnet Mask Number of non-fixed network bits Number of Networks in the class. # of host bit will be # host bit remaining. So let’s say that the first IP address, 192. The following utility converts the IP (TCP/IP) address to other browser URL addressable forms. A class C address means that you must specify 24 bits for the network identification and 8 bits for the host. Every network address calculator from ip and subnet mask device connected to the public internet is assigned an IP address. IP Subnet Calculator - Networks And CIDR (Mask) Feb 5, 2010. A common subnet mask for a Class C IP address is 255. Online IP Subnet Calculator - description of a subnetting related terms in IP version 4, like a LAN, IP address, subnet mask, CIDR, address ranges, broadcast and so on. If you do not understand what I mean about boundaries please read that post. How to find out subnet mask from range of IP addresses? e. IP addresses, networks, submasks, and CIDR notation can be difficult concepts to understand. Routing protocols must base their routing decisions on a 32-bit IP address and a prefix length that can be up to 32 bits. So this can be assigned to Management. Subnets masks are 32 bit addresses like IP Addresses. Initially the network mask is shown according to IP ADDRESS Class for calculations of classful networks. How to Find the Subnet Number of an IP Address - Duration: A lecture on subnetting, calculating the subnets, and the magic number. Notice that this is less than the 65,534 nodes an unsubnetted class B address would have. 3 However, we would need the routing table or the equivalent if there are any ambiguous subnets, since the routing table provides an order of precedence. I would prefer to be specific with the ACL and only block the IP range that is generating the attack. 255 There is an alternative way of calculating your wildcard mask which follows on from the Subnetting Made Easy post about boundaries. Best Answer: Lets start out by finding the subnet mask. Your network adress: In binary the last octet has to be null : xxxxxxxx. Online IP Subnet Calculator - description of a subnetting related terms in IP version 4, like a LAN, IP address, subnet mask, CIDR, address ranges, broadcast and so on. 0/16 into 4 equal sized subnets. 1 goes to the same network (Network A), like 200. An IP address is made up of two components, a network address and a host address. This IP Subnet calculator helps you to calculate the network mask, wildcard mask, network address, broadcast address, start ip, end ip and total IP count of a subnet from the given IP address and mask. IP addresses: Networks and hosts An IP address is a 32-bit number that uniquely identifies a host (computer or other device, such as a printer or router) on a TCP/IP network. To calculate the Subnets IP Address you need to perform a bit-wise AND operation (1+1=1, 1+0 or 0+1 =0, 0+0=0) on the host IP address and subnet mask. Apply the subnet mask to the assigned IP address space to calculate the network address of the new possible subnets, the broadcast address for each possible subnet, and the range of usable IP addresses in each possible subnet. UInt32 To IP Address: 21. x when configuring addresses and networks. Computers use it to determine the network part and the host part of an IP address. Is Ip Address By Regular Expression: 26. 32/27 we will first find the first usable host IP address by changing the right-most host bit to 1 of the subnet address. To understand the IP subnetwork boundaries, let's look at the IP address and subnet mask for our destination device: 192. The goal is to make sure that each router is in a different netwok. Subnet masks define the number of bits that the network will use to assign IP addresses. How to determine hosts, networks and subnets; Step 4: Subnetting backwards Tutorial on reverse calculation of the subnet mask. 255 are reserved for loopback interfaces – Most systems use 127. 4 shows your present addressing scheme for subnet 172. Subnet mask = 2 bits = 128 + 64 = 192 Range of hosts = 2 6 = 64 TT Range Useable Range Network ID 0 – 63 64 – 127 65 - 126 128 – 191 129 - 190 Broadcast 192 – 255 Address Borrow 3 bits S S S H H H H H # of subnets = 2 3 = 8 Subnet mask = 3 bits = 128 + 64 + 32 = 224 Range of hosts = 2 5 = 32 Range Useable Range Network ID 0 – 31. This number is greater than thedefault PL indicator of /24. The subnet calculator lets you enter a subnet range (CIDR) and see IP address information about that range You can type your range directly in CIDR notation, or use the optional Mask pull-down: 74. How to Calculate Subnets Subnets and Hosts Borrow 2 bits S S H H H H H H # of subnets = 22 =. Linux - IP subnet calculation with ipcalc ipcalc is a program to perform simple manipulation of IP addresses and is useful for calculating various network masks given an IP address. 00000000 or 255. This tip, reposted from SearchNetworking. Each DNS server database stores all computer names in the world. Subnets masks are 32 bit addresses like IP Addresses. Here, our subnet mask is 255. Consequently, we need to extract the first 3 octets of a host's IP address and compare the result against 192. net by Jeremy Stretch v2. ipcalc takes an IP address and netmask and calculates the resulting broadcast, network, Cisco wildcard mask, and host range. In the example, we stated the identifier for a preconfigured network was 192. IPv4 Subnet Calculator (PHP) Network calculator for subnet mask and other classless (CIDR) network information. 44 with a subnet mask of 255. Class C have 24 network bit and 8 host bits. Unfortunately your computer doesn’t think that way. By now you should be able to look at an IP address and tell what class it is. This is arrived by putting all 1s for the host potion of the IP address. To understand this, we must look at the devices' unique IP addresses as well as the associated subnet mask and default gateway. I've been served with a question to find Major Network Mask and I've only given Host IP address and sub-net mask. -Unique address required for each LAN subnet -Unique address required for each WAN subnet Verify how many hosts are needed per subnet Identify and create a subnet mask that accommodates the design -This is where the movement of the line will extend the mask to go beyond its default (moving the mask to the right, bit by bit). IP Calculator. The subnet calculator lets you enter a subnet range (CIDR) and see IP address information about that range You can type your range directly in CIDR notation, or use the optional Mask pull-down: 74. Subnet mask represented in dotted decimal and in hex; The number of bits in the network and host portions; The number of subnets and the number of hosts per subnet. 0 or /18 When trying to find the number of ip addresses in each subnet the formula is (2^n)-2 where n= the number of host bits which are the 0s. This tells you that the IP address issubnetted. Subnetting can improve security and help to balance overall network traffic. But I need the code to get converted to its corresponding notation to ip range as the above example. IP Network Calculator is a simple application to calculate the network parameters allowing to set the IP address and subnet mask. If you're dealing with classfull IP addresses, you look at the first octet value of the address. If we use the sample IP address from before, 172. 128, or as an IP address with the number of bits indicated as being used for the mask, like 205. Retrying Retrying. Seven Steps to Subnetting Seven Steps to Subnetting v181104. Understand IP address classes and why we use them. We have the CIDR notation and subnet masks. A subnet mask hides, or "masks," the network part of a system's IP address and leaves only the host part as the machine identifier. Change IP Address, Subnet Mask & Default Gateway. So, you should calculate the address requirements of each sub-network individually. address is which. Decimal to binary conversion technique. 0 (also written 150. An IP address can be considered to have a network address and a host identifier. Best Answer: Lets start out by finding the subnet mask. Some of the uses of ipcalc. Let us now have a look at how we can subnet a Class C IP address using a simple method. Necessity to accurately calculate subnet mask can be a very tedious task for individuals lacking thorough understanding of IP addressing, subnetting and other networking concepts. SubnetOnline. The subnet mask field can be expressed in bits or as octets. Initially your IP address is displayed, the real IP from which you connect. This free online Subnet Calculator provides a fast and easy way to calculate all aspects of any IP Address and Subnet Mask. For Subnetting, Subnet Masks are used. The subnet mask sets the network's boundaries. Enter IP address and netmask (decimal separated by dots (e. A subnet mask is used to determine where the network ends and the hosts begin. We are going to subnet it to three different networks with equal host IP addresses; remember we are working on the THIRD octect with the block size of 16. /24 network for use at one of its sites. But if for some reason the instructions were not there, you can find the instruction on the Internet. Step 3) Perform the AND operation on the two addresses. Number of mask bits (CIDR notation) #6. Routing updates must carry the prefix length (the subnet mask) along with the 32-bit IP address. how to calculate tcp/ip IPV4 subnet mask and range Subnetting for Dummies 101 made easy. This makes these addresses more readable to humans. The pad, which will define the pad in between the subnet IDs,. In this guide, we will cover some of the basic ideas behind how these systems work together to allow computers to communicate over the internet. For Example, take a pair of IP address and subnet mask 10. Enter IP address value. If we use the sample IP address from before, 172. Q: I am struggling with answering question type 2 for Class A and B addresses. The same rules apply 0-match, 1-ignore. /24 Enter sizes (number of assignable ip addresses) of subnets to divide major network. 2 subnets are used for routing the packet. A subnet mask works like a filter with the mask identifying the IP address bits that represent the network ID with a 1, and the bits that represent the host ID with a 0. Find ranges of IP addresses for each subnet and new mask. ipcalc takes an IP address and netmask and calculates the resulting broadcast, network, Cisco wildcard mask, and host range. IP address tracking. To better understand how IP addresses and subnet masks work, look at an IP (Internet Protocol) address and see how it is organized. Calculator; Network Calculator (IPv4) IP Address Subnet Mask. Variable Length Subnet Masking "VLSM" is a technique that allows network administrators to divide an IP address space into subnets of different sizes, unlike simple same-size Subnetting. IP address of a network. Figure: Defining the IP address ranges for the second and third subnets. 0, 4, 8, 16, 32, etc…. Subnet mask. IP Address: A logical numeric address that is assigned to every single computer, printer, switch, router or any other device that is part of a TCP/IP-based network; Subnet: A separate and identifiable portion of an organization's network, typically arranged on one floor, building or geographical location; Subnet Mask: A 32-bit number used to. Need for a IPv4 subnet calculator. By looking at the address and subnet mask, you can see how many addresses are found in each subnet and what those addresses are. A full IPv6 subnet mask uses the same 8-hex-word format as an IPv6 address, although some tools allow you to specify only 1 hex word.