Given an IP CIDR (e.g. 10.20.30.40/20
), explain and illustrate the address,
network, masks, and host address range.
go get -u github.com/pda/cidrinfo
$ cidrinfo 10.20.30.40/20
CIDR: 10.20.30.40/20
IP bits: 32 (IPv4) |-------------- 32 ---------------|
IP address: 10.20.30.40 00001010 00010100 00011110 00101000
Network bits: 20 (..../20) |-------- 20 --------|
Network mask: 255.255.240.0 11111111 11111111 11110000 00000000
Host bits: 12 (32 - 20) |--- 12 ----|
Host mask: 0.0.15.255 00000000 00000000 00001111 11111111
Number of IPs: 4096 (2 ^ 12)
First IP: 10.20.16.0 00001010 00010100 00010000 00000000
Last IP: 10.20.31.255 00001010 00010100 00011111 11111111
$ cidrinfo 2001:0db8:85a3:0000:0000:8a2e:0370:7334/64
CIDR: 2001:0db8:85a3:0000:0000:8a2e:0370:7334/64
IP bits: 128 (IPv6) |-------------------------------------------------------------------- 128 --------------------------------------------------------------------|
IP address: 2001:db8:85a3::8a2e:370:7334 00100000 00000001 00001101 10111000 10000101 10100011 00000000 00000000 00000000 00000000 10001010 00101110 00000011 01110000 01110011 00110100
Network bits: 64 (..../64) |-------------------------------- 64 ---------------------------------|
Network mask: ffff:ffff:ffff:ffff:: 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Host bits: 64 (128 - 64) |-------------------------------- 64 ---------------------------------|
Host mask: ::ffff:ffff:ffff:ffff 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111
Number of IPs: 18446744073709551616 (2 ^ 64)
First IP: 2001:db8:85a3:: 00100000 00000001 00001101 10111000 10000101 10100011 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Last IP: 2001:db8:85a3:0:ffff:ffff:ffff:ffff 00100000 00000001 00001101 10111000 10000101 10100011 00000000 00000000 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111
Made in Australia by Paul Annesley |
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