Subnet Calculator - Cisco. 2020-06-03 subnetcalc 2.4.16-1 MIGRATED to testing (Debian testing watch) 2020-06-01 Accepted subnetcalc 2.4.16-1 (source) into unstable (Thomas Dreibholz) (signed by: Adrian Bunk)2019-09-06 subnetcalc 2.4.13-1 MIGRATED to testing (Debian testing watch).
Use this Subnet Calculator to determine the properties of a network subnet. The query can be in a number of forms including network CIDR addresses and IP with network mask.
What is this Subnet Lookup?
When working with networks it is often required to quickly calculate the network boundaries of a subnet from a CIDR address or subnet with network mask. CIDR notation format is a way to express IP addresses and their associated routing prefix. It appends a slash character to the address and the decimal number of leading bits of the routing prefix, e.g., 192.168.2.0/24 for IPv4, and 2001:db8::/32 for IPv6.
Format of the Subnet to Lookup
Enter the subnet to lookup using one of the following formats.
IPv6 Subnet Lookup
Todoist business registration. Lookup IPv6 subnets using the same format. Simply enter the IPv6 address and include a CIDR notation.
Here are some examples:
2a01:7e00::f03c:91ff:fe70:d437/64
API for the Subnet Calculator
In addition to the web form on this page there is another way to quickly lookup a subnet details. Output is simple and of content type text.
The API is simple to use and aims to be a quick reference tool. Like all our IP Tools there is a limit of 50 queries per day or you can Remove limits with a Full Membership.
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This calculator returns a variety of information regarding Internet Protocol version 4 (IPv4) and IPv6 subnets including possible network addresses, usable host ranges, subnet mask, and IP class, among others.
IPv4 Subnet Calculator
IPv6 Subnet Calculator
![SubnetCalc SubnetCalc](/uploads/1/1/1/6/111696227/511657160.png)
A subnet is division of an IP network (internet protocol suite), where an IP network is a set of communications protocols used on the Internet and other similar networks. It is commonly known as TCP/IP (Transmission Control Protocol/Internet Protocol).
The act of dividing a network into at least two separate networks is called subnetting, and routers are devices that allow traffic exchange between subnetworks, serving as a physical boundary. IPv4 is the most common network addressing architecture used, though the use of IPv6 has been growing since 2006.
Ipv6 Subnet Calc
An IP address is comprised of a network number (routing prefix) and a rest field (host identifier). A rest field is an identifier that is specific to a given host or network interface. A routing prefix is often expressed using Classless Inter-Domain Routing (CIDR) notation for both IPv4 and IPV6. CIDR is a method used to create unique identifiers for networks, as well as individual devices. For IPv4, networks can also be characterized using a subnet mask, which are sometimes expressed in dot-decimal notation, as shown in the 'Subnet' field in the calculator. All hosts on a subnetwork have the same network prefix, unlike the host identifier which is a unique local identification. In IPv4, these subnet masks are used to differentiate the network number and host identifier. In IPv6, the network prefix performs a similar function as the subnet mask in IPv4, with the prefix length representing the number of bits in the address.
Prior to the introduction of CIDR, IPv4 network prefixes could be directly obtained from the IP address based on the class (A, B, or C, which vary based on the range of IP addresses they include) of the address and the network mask. Since CIDRs introduction however, assigning an IP address to a network interface requires both an address and its network mask.
Below is a table providing typical subnets for IPv4.
Subnetcalc Mac
Prefix size | Network mask | Usable hosts per subnet |
/1 | 128.0.0.0 | 2,147,483,646 |
/2 | 192.0.0.0 | 1,073,741,822 |
/3 | 224.0.0.0 | 536,870,910 |
/4 | 240.0.0.0 | 268,435,454 |
/5 | 248.0.0.0 | 134,217,726 |
/6 | 252.0.0.0 | 67,108,862 |
/7 | 254.0.0.0 | 33,554,430 |
Class A | ||
/8 | 255.0.0.0 | 16,777,214 |
/9 | 255.128.0.0 | 8,388,606 |
/10 | 255.192.0.0 | 4,194,302 |
/11 | 255.224.0.0 | 2,097,150 |
/12 | 255.240.0.0 | 1,048,574 |
/13 | 255.248.0.0 | 524,286 |
/14 | 255.252.0.0 | 262,142 |
/15 | 255.254.0.0 | 131,070 |
Class B | ||
/16 | 255.255.0.0 | 65,534 |
/17 | 255.255.128.0 | 32,766 |
/18 | 255.255.192.0 | 16,382 |
/19 | 255.255.224.0 | 8,190 |
/20 | 255.255.240.0 | 4,094 |
/21 | 255.255.248.0 | 2,046 |
/22 | 255.255.252.0 | 1,022 |
/23 | 255.255.254.0 | 510 |
Class C | ||
/24 | 255.255.255.0 | 254 |
/25 | 255.255.255.128 | 126 |
/26 | 255.255.255.192 | 62 |
/27 | 255.255.255.224 | 30 |
/28 | 255.255.255.240 | 14 |
/29 | 255.255.255.248 | 6 |
/30 | 255.255.255.252 | 2 |
/31 | 255.255.255.254 | 0 |
/32 | 255.255.255.255 | 0 |