• The Netmask/CIDR tool is for network administrators or network engineers or webmasters who need to generate a list of IP Addresses and network Addresses that falls into the category of the input IP and netmask/CIDR. The user need to input an IP along with netmask or CIDR to generate the list of IP Addresses and network addresses.
  • Netmask to IPv4 Conversion CIDR is the short for Classless Inter-Domain Routing, an IP addressing scheme that replaces the older system based on classes A, B, and C. A single IP address can be used to designate many unique IP addresses with CIDR.
  • The DNS Made Easy Subnet mask cheat sheet was designed by sys admins, for sys admins. We hope you find it as useful as we do.
  • Further subnetting separates the host part of an IP address into a subnet and host address if additional subnetwork is needed. This IP subnetting calculator is designed considering the ease of use to the user.

The netmask is used to specify the IP range a 'network' starts and stops at. This range is arbitrary. For example, with the IP address With the netmask of (/24 in cidr notation) the IP range would be -

There are plenty of these netmask references out there, but I prefer myown: hence this Tech Tip. We've never seen anybody use a network largerthan a /4 (256M hosts), so we've truncated the table at that point.

Netmask Quick Reference
# bits # hosts Usable
netmask Cisco mask
/4 268435456 268435454
/5 134217728 134217726
/6 67108864 67108862
/7 33554432 33554430
/8 16777216 16777214 class A network
/9 8388608 8388606
/10 4194304 4194302
/11 2097152 2097150
/12 1048576 1048574
/13 524288 524286
/14 262144 262142
/15 131072 131070
/16 65536 65534 class B network
/17 32768 32766
/18 16384 16382
/19 8192 8190
/20 4096 4094
/21 2048 2046
/22 1024 1022
/23 512 510
/24 256 254 class C network
/25 128 126
/26 64 62
/27 32 30
/28 16 14
/29 8 6
/30 4 2
/31 point to point links only
/32 1 1 single IP address use host notation

All devices on a local network have a unique IP address, but eachaddress is inherently divided into two parts, a shared network part,and a unique host part, and this information is used by the TCP/IP stackfor routing. When sending traffic to a machine with a different networkpart, it must be sent through a router for final delivery.

How To Connect MetaMask Wallet To Binance Smart Chain (BSC)

The dividing line between the network and host parts is determinedby the subnet mask, and it's often seen in It looks like an IP address, and it uses a '1' bit toselect, or 'mask' the network part.

Find out what my netmask is14.04):

In this case, the netmask of represents 29bits of network and 3 bits of host (totalling 32 bits, of course),and this give 8 possible IP addresses in this range. The first andlast of the range are reserved addresses, giving 6 usable addressesthat may be assigned to a device. zero broadcast available available available available available available ones broadcast

When creating ACLs for Cisco routers,one specifies networks using a base IP address and what looks like an invertednetmask: rather than set a one bit for each part of the address that's a network,they set a one bit for each part that's a host. Xbox one fm21.

Many consider this quite annoying, as it's one more thing to have to remember.

First published: 2005/07/17

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.


Networking - How Do I Find My Network IP Address, Netmask ..

IPv4 Subnet Calculator

IPv6 Subnet Calculator

RelatedBandwidth Calculator Binary Calculator

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.

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.

Prefix sizeNetwork maskUsable hosts per subnet
Class A
Class B
Class C