IPV4-IPV6过渡技术之6to4隧道

 

IPV4-IPV6过渡技术之6to4隧道

(2012-12-14 14:06:22)

1 、 6to4 tunnel 编址

在 IPV6 全局单播地址中，有一段地址保留给了 6to4 的 tunnel （ IANA 规定， http://www.ietf.org/assignments/ipv6-unicast-address-assignments/ipv6-unicast-address-assignments.xml ），地址范围为 2002::/16 ， 6to4 中用到的位 2002::/48 （融入了 IPV4 的 32bit) 地址网段这是在 6to4tunnel 中要利用到的地址，并且一定是要用此地址网段。 (RFC3056)

 

    The IANA has permanently assigned one 13-bit IPv6 Top Level
    Aggregator (TLA) identifier under the IPv6 Format Prefix 001 [AARCH,
    AGGR] for the 6to4 scheme.Its numeric value is 0x0002, i.e., it is
    2002::/16 when expressed as an IPv6 address prefix.

The subscriber site is then deemed to have the following IPv6 address
    prefix, without any further assignment procedures being necessary:

Prefix length: 48 bits
          Format prefix: 001
          TLA value: 0x0002
          NLA value: V4ADDR

This is illustrated as follows:

      |   3    |      13    |         32            |      16     |               64 bits                 |
     +--- -- +------ ---- +----------- ----- +-------- -- +-------------------------------+
     |FP    |     TLA    | V4ADDR      | SLA ID |         Interface ID              |
     |001|0x0002|                        |               |                                               |
      +--- -- +------ ---- +----------- ----- +-------- -- +-------------------------------+

Thus, this prefix has exactly the same format as normal /48 prefixes
    assigned according to [ AGGR].  It can be abbreviated as
    2002:V4ADDR::/48.  Within the subscriber site it can be used exactly
    like any other valid IPv6 prefix, e.g., for automated address
    assignment and discovery according to the normal mechanisms such as
    [ CONF, DISC], for native IPv6 routing, or for the "6over4" mechanism
    [ 6OVER4].

 

 

2 、 6to4 tunnel 细节；

 

6to4tunnel 不仅适用在两个 ipv6 孤岛穿越 IPV4 核心进行通信的路由器环境中，而且还适用于主机路由器环境、路由器到主机等环境。为了和前面一致，还是使用下图；