Subnets

Network and IP address calculator

Show network, broadcast, first and last address for a given network:

IP/Netmask bits: /

result:

Usable addresses:
Mask:
Network:
First usable:
Last usable:
Broadcast:

The netmask in “bits format” is also known as mask in CIDR format (CIDR=Classless Inter-Domain Routing)

Converters for Network and IP address

Subnet Mask Converter (dotted decimal to bits format)

result: /

Subnet Mask Converter (bits format to dotted decimal)

/

result:

Dec:

Hex:


Number of required addresses to netmask converter

number of addresses needed:

result:

mask: /
dotted dec. mask:
usable amount of addresses:


Convert dotted decimal IP-address or mask to binary and hex

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Hex:


Convert hex IP-address or mask dotted decimal

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dotted decimal:

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Calculate the bit-complement of an IP-address (invert)


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Convert a Network Mask to amount of usable addresses

Mask: /

result:

Usable amount of addr:
Total number of addr:

Netmaks in dotted decimal format:


Convert decimal to binary and hex

Dec:

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Bin:

Hex:

 

Convert binary to decimal and hex

Bin:

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Dec:

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Convert hex to decimal and binary

Hex:

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Dec:

Bin:


Common subnet address ranges

Prefix size Subnet mask Available subnets Usable hosts per subnet Total usable hosts
24 255.255.255.0 1 254 254
25 255.255.255.128 2 126 252
26 255.255.255.192 4 62 248
27 255.255.255.224 8 30 240
28 255.255.255.240 16 14 224
29 255.255.255.248 32 6 192
30 255.255.255.252 64 2 128
31 255.255.255.254 128 2 256

IP Multicast address ranges

All multicast addresses can easily be recognized because they start with the bit pattern “1110”.

224.0.0.0 – 224.0.0.255 Well-known multicast addresses, control channels

224.0.1.0 – 238.255.255.255 Globally-scoped (Internet-wide) multicast addresses

239.0.0.0 – 239.255.255.255 Local multicast addresses

Special and private address ranges

Private address ranges are not routed on the Internet and can be freely allocated in any private network. NAT (network address translation) is required when connecting such a network to the Internet.

Private network addresses (RFC1597/RFC1918 addresses):

10.0.0.0 – 10.255.255.255 A 24-bit block, /8, class A network

172.16.0.0 – 172.31.255.255 A 20-bit block, /12, set of 16 contiguous class B network numbers

192.168.0.0 – 192.168.255.255 A 16-bit block, /16, set of 255 contiguous class C network numbers

Special addresses:

127.0.0.0 – 127.255.255.255 Special address range for the localhost. You can normally not use those addresses for anything else.


127.0.0.1 is generally assigned to the loopback device

0.0.0.0 Special host address commonly reserved for the default route