IP Subnet Calculator

A step-by-step guide to use IPTP Networks’ IPv4 Subnet Calculator

Choose the preferred Network class, which is determined by its first bits, by clicking either three options:

• Class A (8 bits), B (16 bits) and C (24 bits)
• Select the target Subnet from the dropbox according to the Network class you chose
• Enter the IP address. An example IP address is already in place and can be used immediately

Hit the Calculate button to view the result list of all the network and IP address values.

The necessary data IPv4 Subnet Calculator needs to calculate:

• Network class:Network is divided into Class A, Class B and Class C. Class A network uses the first 8 bits of the IP address as its “network part.”, while Class B uses the first 16 bits and Class C uses the first 24 bits
• Subnet:Subnet includes two parts: The subnet mask, followed by the CIDR notation
• IP address:IPv4 address uses a 32-bit address and can support 232 IP addresses. IPv4 has 4 groups of numbers – called octets. Each octet ranges between 0 and 255 and is separated by dots (.)

IPv4 Subnet Calculator tool will use that information to calculate and display comprehensive information about:

• Network Address:The first part of the subnet mask and is the same with the first part of the IP address.
• Broadcast Address:The last address on the subnet. It is used to send data (broadcast) to every host on that subnet.
• Total Number of Hosts:Total number of addresses available on the network.
• Usable Host IP Range:It refers to the range of IP addresses that can be assigned to hosts. The range starts with the address right after the network address and ends at one address before the broadcast address.
• Number of Usable Hosts:The addresses that can be assigned to hosts. The total number of addresses without the first address (the network address) and the last address (the broadcast address).
• Wildcard Mask:Wildcard masks refers to the inverted bits of the subnet mask to be used with routing protocols (OSPF) and access control lists (ACLs).
• Binary Subnet Mask:Subnet mask in binary format.
• IP Class:IP addresses are categorized into five classes, ranging from Class A to E. Class D is for multicasting and Class E is for future use.
• CIDR Notation:IP address is written with a number of bits (CIDR number), with a forward-slash (/) in between.
• IP Type:Show whether the IP address is public (on the Internet) or private (local networks).
• Binary ID:IP address in binary format, which consists of only 0s and 1s.
• Integer ID:IP address in integer format, which consists of numbers from 0 – 9.
• Hex ID:IP address in hexadecimal format, which starts with the “0x”, and consists of numbers from 0 – 9 and letters from A – F.
• In-addr.arpa:A domain name for reverse DNS lookup. It is the IP addresses in the reverse order. For example, when looking up the IP address of 27.78.101.154, the returned result is 154.101.78.27.in-addr.arpa.
• IPv4 Mapped Address:IPv4 Mapped Address is used to present a 32-bit IPv4 address as a 128-bit IPv6 address. Its format starts with 80 “0” bits, followed by 16 bits set in 1s (“FFFF” in hexadecimal), and ends with the original 32-bit IPv4 address written in hexadecimal format.
• 6to4 Prefix:6to4 is an IPv4 to IPv6 migration scheme. 6to4 addresses always start with 2002, followed by the original 32-bit IPv4 address written in hexadecimal format. IPv4 Subnet Calculator will also return the data about all the possible networks for that IP address (Network Address, Usable Host Range, Broadcast Address).