rfc1228.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

Carpenter & Wijnen                                             [Page 12]

RFC 1228                        SNMP-DPI                        May 1991


GET-NEXT

   When the SNMP agent receives a PDU containing an SNMP GET-NEXT
   request for a variable for which a sub-agent may be authoritative, it
   passes an SNMP DPI GET-NEXT packet to the sub-agent.

   Such a packet contains the standard SNMP DPI header plus GET-NEXT-
   specific data.  These data take the form of two null terminated
   strings.  The first string represents the object ID in dotted ASN.1
   notation; the second string represents the group ID in dotted ASN.1
   notation.

+----------------------------------------------------------------------+
| Table 6. SNMP DPI GET NEXT packet.  This is the layout of an SNMP    |
|          DPI GET NEXT packet                                         |
+-------------+--------------------------------------------------------+
| OFFSET      | FIELD                                                  |
+-------------+--------------------------------------------------------+
| 0           | packet length to follow (MSB)                          |
+-------------+--------------------------------------------------------+
| 1           | packet length to follow (LSB)                          |
+-------------+--------------------------------------------------------+
| 2           | protocol major version                                 |
+-------------+--------------------------------------------------------+
| 3           | protocol minor version                                 |
+-------------+--------------------------------------------------------+
| 4           | protocol release                                       |
+-------------+--------------------------------------------------------+
| 5           | packet type = SNMP_DPI_GET_NEXT                        |
+-------------+--------------------------------------------------------+
| 6           | null terminated object ID                              |
+-------------+--------------------------------------------------------+
| 6 + len     | null terminated group ID                               |
+-------------+--------------------------------------------------------+
| NOTE:  len=strlen(object ID)+1                                       |
+----------------------------------------------------------------------+
+----------------------------------------------------------------------+














Carpenter & Wijnen                                             [Page 13]

RFC 1228                        SNMP-DPI                        May 1991


SET

   When the SNMP agent receives a PDU containing an SNMP SET request for
   a variable that a sub-agent registered with the agent, it passes an
   SNMP DPI SET packet to the sub-agent.

   Such a packet contains the standard SNMP DPI header plus SET specific
   data, which is basically a null terminated string representing the
   object ID in ASN.1 notation, with the type, value length and value to
   be set.  The permitted types for the type field are defined in Table
   12 on page 19.  Integer values are sent as 4-byte elements in network
   byte order (most significant byte first, least significant byte
   last).

+----------------------------------------------------------------------+
| Table 7. SNMP DPI SET packet.  This is the layout of an SNMP DPI SET |
|          packet                                                      |
+-------------+--------------------------------------------------------+
| OFFSET      | FIELD                                                  |
+-------------+--------------------------------------------------------+
| 0           | packet length to follow (MSB)                          |
+-------------+--------------------------------------------------------+
| 1           | packet length to follow (LSB)                          |
+-------------+--------------------------------------------------------+
| 2           | protocol major version                                 |
+-------------+--------------------------------------------------------+
| 3           | protocol minor version                                 |
+-------------+--------------------------------------------------------+
| 4           | protocol release                                       |
+-------------+--------------------------------------------------------+
| 5           | packet type = SNMP_DPI_SET                             |
+-------------+--------------------------------------------------------+
| 6           | null terminated object ID                              |
+-------------+--------------------------------------------------------+
| 6 + len     | SNMP Variable Type Value                               |
+-------------+--------------------------------------------------------+
| 6 + len + 1 | Length of value (MSB)                                  |
+-------------+--------------------------------------------------------+
| 6 + len + 2 | Length of value (LSB)                                  |
+-------------+--------------------------------------------------------+
| 6 + len + 3 | Value                                                  |
+-------------+--------------------------------------------------------+
| NOTE:  len=strlen(object ID)+1                                       |
+----------------------------------------------------------------------+
+----------------------------------------------------------------------+






Carpenter & Wijnen                                             [Page 14]

RFC 1228                        SNMP-DPI                        May 1991


RESPONSE

   An SNMP sub-agent must respond to a GET, GET_NEXT or SET request that
   it has received from the agent (unless it fails or has a bug).  To do
   so, it sends an SNMP DPI RESPONSE packet to the agent.

   Such a packet contains the standard SNMP DPI header plus RESPONSE
   specific data, which basically is an error_code plus (if there was no
   error), the name/type/value tuple representing the returned object.
   This is described as by a string representing the object ID in ASN.1
   notation, plus the type, value length and value of the object that
   was manipulated.  The permitted types for the type field are defined
   in Table 12 on page 19.  Integer values are sent as 4-byte elements
   in network byte order (most significant byte first, least significant
   byte last).




































Carpenter & Wijnen                                             [Page 15]

RFC 1228                        SNMP-DPI                        May 1991


+----------------------------------------------------------------------+
| Table 8. SNMP DPI RESPONSE packet.  This is the layout of an SNMP    |
|          DPI RESPONSE packet                                         |
+-------------+--------------------------------------------------------+
| OFFSET      | FIELD                                                  |
+-------------+--------------------------------------------------------+
| 0           | packet length to follow (MSB)                          |
+-------------+--------------------------------------------------------+
| 1           | packet length to follow (LSB)                          |
+-------------+--------------------------------------------------------+
| 2           | protocol major version                                 |
+-------------+--------------------------------------------------------+
| 3           | protocol minor version                                 |
+-------------+--------------------------------------------------------+
| 4           | protocol release                                       |
+-------------+--------------------------------------------------------+
| 5           | packet type = SNMP_DPI_RESPONSE                        |
+-------------+--------------------------------------------------------+
| 6           | SNMP error code                                        |
+-------------+--------------------------------------------------------+
| 7           | null terminated object ID                              |
+-------------+--------------------------------------------------------+
| 7 + len     | SNMP Variable Type Value                               |
+-------------+--------------------------------------------------------+
| 7 + len + 1 | Length of value (MSB)                                  |
+-------------+--------------------------------------------------------+
| 7 + len + 2 | Length of value (LSB)                                  |
+-------------+--------------------------------------------------------+
| 7 + len + 3 | Value                                                  |
+-------------+--------------------------------------------------------+
| NOTE:  len=strlen(object ID)+1                                       |
+----------------------------------------------------------------------+
+----------------------------------------------------------------------+

TRAP

   An SNMP sub-agent can request the agent to generate a TRAP by sending
   an SNMP DPI TRAP packet to the agent.

   Such a packet contains the standard SNMP DPI header plus TRAP
   specific data, which is basically the generic and specific trap code,
   plus a name/type/value tuple.  The tuple is described by a string
   representing the object ID in ASN.1 notation, plus the type, value
   length and value of the object that is being sent in the trap.  The
   permitted types for the type field are defined in Table 12 on page
   19.  Integer values are sent as 4-byte elements in network byte order
   (most significant byte first, least significant byte last).




Carpenter & Wijnen                                             [Page 16]

RFC 1228                        SNMP-DPI                        May 1991


+----------------------------------------------------------------------+
| Table 9. SNMP DPI TRAP packet.  This is the layout of an SNMP DPI    |
|          TRAP packet                                                 |
+-------------+--------------------------------------------------------+
| OFFSET      | FIELD                                                  |
+-------------+--------------------------------------------------------+
| 0           | packet length to follow (MSB)                          |
+-------------+--------------------------------------------------------+
| 1           | packet length to follow (LSB)                          |
+-------------+--------------------------------------------------------+
| 2           | protocol major version                                 |
+-------------+--------------------------------------------------------+
| 3           | protocol minor version                                 |
+-------------+--------------------------------------------------------+
| 4           | protocol release                                       |
+-------------+--------------------------------------------------------+
| 5           | packet type - SNMP_DPI_TRAP                            |
+-------------+--------------------------------------------------------+
| 6           | SNMP generic trap code                                 |
+-------------+--------------------------------------------------------+
| 7           | SNMP specific trap code                                |
+-------------+--------------------------------------------------------+
| 8           | null terminated object ID                              |
+-------------+--------------------------------------------------------+
| 8 + len     | SNMP Variable Type Value                               |
+-------------+--------------------------------------------------------+
| 8 + len + 1 | Length of value (MSB)                                  |
+-------------+--------------------------------------------------------+
| 8 + len + 2 | Length of value (LSB)                                  |
+-------------+--------------------------------------------------------+
| 8 + len + 3 | Value                                                  |
+-------------+--------------------------------------------------------+
| NOTE:  len=strlen(object ID)+1                                       |
+----------------------------------------------------------------------+
+----------------------------------------------------------------------+
















Carpenter & Wijnen                                             [Page 17]

RFC 1228                        SNMP-DPI                        May 1991


CONSTANTS AND VALUES

   This section describes the constants that have been defined for this
   version of the SNMP DPI Protocol.

PROTOCOL VERSION AND RELEASE VALUES

+----------------------------------------------------------------------+
| Table 10. Protocol version and release values                        |
+-----------------------------------+----------------------------------+
| FIELD                             | VALUE                            |
+-----------------------------------+----------------------------------+
| protocol major version            | 2 (SNMP DPI protocol)            |
+-----------------------------------+----------------------------------+
| protocol minor version            | 1 (version 1)                    |
+-----------------------------------+----------------------------------+
| protocol release                  | 0 (release 0)                    |
+-----------------------------------+----------------------------------+
+----------------------------------------------------------------------+

Any other values are currently undefined.

PACKET TYPE VALUES

   The packet type field can have the following values:

+----------------------------------------------------------------------+
| Table 11. Valid values for the packet type field                     |
+-------+--------------------------------------------------------------+
| VALUE | PACKET TYPE                                                  |
+-------+--------------------------------------------------------------+
| 1     | SNMP_DPI_GET                                                 |
+-------+--------------------------------------------------------------+
| 2     | SNMP_DPI_GET_NEXT                                            |
+-------+--------------------------------------------------------------+
| 3     | SNMP_DPI_SET                                                 |
+-------+--------------------------------------------------------------+
| 4     | SNMP_DPI_TRAP                                                |
+-------+--------------------------------------------------------------+
| 5     | SNMP_DPI_RESPONSE                                            |
+-------+--------------------------------------------------------------+
| 6     | SNMP_DPI_REGISTER                                            |
+-------+--------------------------------------------------------------+
+----------------------------------------------------------------------+