曾经以为保留地址下面三类.原来使用中还有很多的.

A类 10.0.0.0--10.255.255.255

B类 172.16.0.0--172.31.255.255

C类 192.168.0.0--192.168.255.255

Address Block                    Name                              RFC
0.0.0.0/8                        "This host on this network"       [RFC1122], section 3.2.1.3
10.0.0.0/8                       Private-Use                       [RFC1918]
100.64.0.0/10                    Shared Address Space              [RFC6598]
127.0.0.0/8                      Loopback                          [RFC1122], section 3.2.1.3
169.254.0.0/16                   Link Local                        [RFC3927]
172.16.0.0/12                    Private-Use                       [RFC1918]
192.0.0.0/24[2]                  IETF Protocol Assignments         [RFC6890], section 2.1
192.0.0.0/29                     IPv4 Service Continuity Prefix    [RFC7335]
192.0.0.8/32                     IPv4 dummy address                [RFC7600]
192.0.0.9/32                     Port Control Protocol Anycast     [RFC-ietf-pcp-anycast-08]
192.0.0.170/32, 192.0.0.171/32   NAT64/DNS64 Discovery             [RFC7050], section 2.2
192.0.2.0/24                     Documentation (TEST-NET-1)        [RFC5737]
192.31.196.0/24                  AS112-v4                          [RFC7535]
192.52.193.0/24                  AMT                               [RFC7450]
192.88.99.0/24                   Deprecated (6to4 Relay Anycast)   [RFC7526]
192.168.0.0/16                   Private-Use                       [RFC1918]
192.175.48.0/24                  Direct Delegation AS112 Service   [RFC7534]
198.18.0.0/15                    Benchmarking                      [RFC2544]
198.51.100.0/24                  Documentation (TEST-NET-2)        [RFC5737]
203.0.113.0/24                   Documentation (TEST-NET-3)        [RFC5737]
240.0.0.0/4                      Reserved                          [RFC1112], section 4
255.255.255.255/32               Limited Broadcast                 [RFC919], section 7

http://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml