36. Private Network Address Spaces

• Private network address spaces published in RFC 1918

      ____________________________________________________
      RFC1918 name  IP address range  Number of addresses
      ____________________________________________________
      24-bit block  10.0.0.0          16,777,216
                    10.255.255.255
  
      20-bit block  172.16.0.0        1,048,576
                    172.31.255.255
  
      16-bit block  192.168.0.0       65,536
                    192.168.255.255
  

• If ethernet host cannot obtain IP via DHCP, an address range

                    169.254.0.0
                    169.254.255.255
  

  is randomly assigned. The technique is known as Link-Local address assignment (RFC 3927), however, Microsoft refers to it as Automatic Private IP Addressing (APIPA).