The copied flag indicates that this option is copied into all fragments on fragmentation.
0 = not copied 1 = copied
The option classes are:
0 = control 1 = reserved for future use 2 = debugging and measurement 3 = reserved for future use
[Page 15]
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.
[Page 16]
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 group) parameters. The format for this option is as follows:
精品推荐