IPv4 Subnetting

packetlife.net by Jeremy Stretch v2.0 IPV4 SUBNETTING Terminology Subnets CIDR /32 255.255.255.255 1 Subnet Mask Addresses Wildcard 0.0.0.0 /31 255.255.255.254 2 0.0.0.1 /30 255.255.255.252 4 0.0.0.3 /29 255.255.255.248 8 0.0.0.7 /28 255.255.255.240 16 0.0.0.15 /27 255.255.255.224 32 0.0.0.31 /26 255.255.255.192 64 0.0.0.63 /25 255.255.255.128 128 0.0.0.127 /24 255.255.255.0 256 0.0.0.255 /23 255.255.254.0 512 0.0.1.255 /22 255.255.252.0 1,024 0.0.3.255 /21 255.255.248.0 2,048 0.0.7.255 /20 255.255.240.0 4,096 0.0.15.255 /19 255.255.224.0 8,192 0.0.31.255 /18 255.255.192.0 16,384 0.0.63.255 /17 255.255.128.0 32,768 0.0.127.255 /16 255.255.0.0 65,536 0.0.255.255 /15 255.254.0.0 131,072 0.1.255.255 /14 255.252.0.0 262,144 0.3.255.255 /13 255.248.0.0 524,288 0.7.255.255 /12 255.240.0.0 1,048,576 0.15.255.255 /11 255.224.0.0 2,097,152 0.31.255.255 /10 255.192.0.0 4,194,304 0.63.255.255 /9 255.128.0.0 8,388,608 0.127.255.255 /8 255.0.0.0 16,777,216 0.255.255.255 /7 254.0.0.0 33,554,432 1.255.255.255 /6 252.0.0.0 67,108,864 3.255.255.255 /5 248.0.0.0 134,217,728 7.255.255.255 /4 240.0.0.0 268,435,456 15.255.255.255 /3 224.0.0.0 536,870,912 31.255.255.255 /2 192.0.0.0 1,073,741,824 63.255.255.255 /1 128.0.0.0 2,147,483,648 127.255.255.255 /0 0.0.0.0 4,294,967,296 255.255.255.255 Decimal to Binary Subnet Mask Wildcard 255 1111 1111 0 0000 0000 254 1111 1110 1 0000 0001 252 1111 1100 3 0000 0011 248 1111 1000 7 0000 0111 240 1111 0000 15 0000 1111 224 1110 0000 31 0001 1111 192 1100 0000 63 0011 1111 128 1000 0000 127 0111 1111 0 0000 0000 255 1111 1111 Subnet Proportion Classful Ranges A 0.0.0.0 – 127.255.255.255 B 128.0.0.0 - 191.255.255.255 C 192.0.0.0 - 223.255.255.255 D 224.0.0.0 - 239.255.255.255 E 240.0.0.0 - 255.255.255.255 Reserved Ranges RFC 1918 10.0.0.0 - 10.255.255.255 Localhost 127.0.0.0 - 127.255.255.255 RFC 1918 172.16.0.0 - 172.31.255.255 RFC 1918 192.168.0.0 - 192.168.255.255 /29 /30 /30 CIDR Classless interdomain routing was developed to provide more granularity than legacy classful addressing; CIDR notation is expressed as /XX /25 /26 /27 /28 VLSM Variable-length subnet masks are an arbitrary length between 0 and 32 bits; CIDR relies on VLSMs to define routes