0 = control
      1 = reserved for future use
      2 = debugging and measurement
      3 = reserved for future use












 

                                                          September 1981
Internet Protocol
Specification



    The following internet options are defined:

      CLASS NUMBER LENGTH DESCRIPTION
      ----- ------ ------ -----------
        0     0      -    End of Option list.  This option occupies only
                          1 octet; it has no length octet.
        0     1      -    No Operation.  This option occupies only 1
                          octet; it has no length octet.
        0     2     11    Security.  Used to carry Security,
                          Compartmentation, User Group (TCC), and
                          Handling Restriction Codes compatible with DOD
                          requirements.
        0     3     var.  Loose Source Routing.  Used to route the
                          internet datagram based on information
                          supplied by the source.
        0     9     var.  Strict Source Routing.  Used to route the
                          internet datagram based on information
                          supplied by the source.
        0     7     var.  Record Route.  Used to trace the route an
                          internet datagram takes.
        0     8      4    Stream ID.  Used to carry the stream
                          identifier.
        2     4     var.  Internet Timestamp.

      

    Specific Option Definitions

      End of Option List

        +--------+
        |00000000|
        +--------+
          Type=0

        This option indicates the end of the option list.  This might
        not coincide with the end of the internet header according to
        the internet header length.  This is used at the end of all
        options, not the end of each option, and need only be used if
        the end of the options would not otherwise coincide with the end
        of the internet header.

        May be copied, introduced, or deleted on fragmentation, or for
        any other reason.







 

September 1981                                                          
                                                       Internet Protocol
                                                           Specification



      No Operation

        +--------+
        |00000001|
        +--------+
          Type=1

        This option may be used between options, for example, to align
        the beginning of a subsequent option on a 32 bit boundary.

        May be copied, introduced, or deleted on fragmentation, or for
        any other reason.

      Security

        This option provides a way for hosts to send security,
        compartmentation, handling restrictions, and TCC (closed user