+----------------------------------------------+ |addrs bits pref class* mask | +----------------------------------------------+ | 1 0 /32 255.255.255.255 | | 2 1 /31 255.255.255.254 | | 4 2 /30 255.255.255.252 | | 8 3 /29 255.255.255.248 | | 16 4 /28 255.255.255.240 | | 32 5 /27 255.255.255.224 | | 64 6 /26 255.255.255.192 | | 128 7 /25 255.255.255.128 | | 256 8 /24 1C 255.255.255 | | 512 9 /23 2C 255.255.254 | | 1K 10 /22 4C 255.255.252 | | 2K 11 /21 8C 255.255.248 | | 4K 12 /20 16C 255.255.240 | | 8K 13 /19 32C 255.255.224 | | 16K 14 /18 64C 255.255.192 | | 32K 15 /17 128C 255.255.128 | | 64K 16 /16 1B 255.255 | | 128K 17 /15 2B 255.254 | | 256K 18 /14 4B 255.252 | | 512K 19 /13 8B 255.248 | | 1M 20 /12 16B 255.240 | | 2M 21 /11 32B 255.224 | | 4M 22 /10 64B 255.192 | | 8M 23 /9 128B 255.128 | | 16M 24 /8 1A 255 | | 32M 25 /7 2A 254 | | 64M 26 /6 4A 252 | | 128M 27 /5 8A 248 | | 256M 28 /4 16A 240 | | 512M 29 /3 32A 224 | |1024M 30 /2 64A 192 | +----------------------------------------------+ The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private internets: 10.0.0.0 - 10.255.255.255 (10/8 prefix) 172.16.0.0 - 172.31.255.255 (172.16/12 prefix) 192.168.0.0 - 192.168.255.255 (192.168/16 prefix) |