Address Block             Present Use                       Reference
   ———————————————————————
   0.0.0.0/8            “This” Network                    [RFC1700, page 4]
   10.0.0.0/8           Private-Use Networks                   [RFC1918]
   14.0.0.0/8           Public-Data Networks         [RFC1700, page 181]
   24.0.0.0/8           Cable Television Networks                    –
   39.0.0.0/8           Reserved but subject
                                         to allocation                       [RFC1797]
   127.0.0.0/8          Loopback                       [RFC1700, page 5]
   128.0.0.0/16         Reserved but subject
                                          to allocation                             –
   169.254.0.0/16       Link Local                                   –
   172.16.0.0/12        Private-Use Networks                   [RFC1918]
   191.255.0.0/16       Reserved but subject
                                            to allocation                             –
   192.0.0.0/24         Reserved but subject
                                           to allocation                             –
   192.0.2.0/24         Test-Net
   192.88.99.0/24       6to4 Relay Anycast                     [RFC3068]
   192.168.0.0/16       Private-Use Networks                   [RFC1918]
   198.18.0.0/15        Network Interconnect
                                         Device Benchmark Testing            [RFC2544]
   223.255.255.0/24     Reserved but subject
                                               to allocation                             –
   224.0.0.0/4          Multicast                              [RFC3171]
   240.0.0.0/4          Reserved for Future Use        [RFC1700, page 4]

From RFC3330