Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide


NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

Enjoy The TCP/IP Guide? Get the complete PDF!
The TCP/IP Guide

Custom Search






Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Network Configuration and Management Protocols (BOOTP, DHCP, SNMP and RMON)
           9  TCP/IP Network Management Framework and Protocols (SNMP and RMON)
                9  TCP/IP Simple Network Management Protocol (SNMP) Protocol
                     9  SNMP Protocol Messaging and Message Formats

Previous Topic/Section
SNMP Version 1 (SNMPv1) Message Format
Previous Page
Pages in Current Topic/Section
1234
5
6
Next Page
SNMP Version 3 (SNMPv3) Message Format
Next Topic/Section

SNMP Version 2 (SNMPv2) Message Formats
(Page 5 of 6)

SNMPv2 PDU Formats

The format of protocol data units in SNMPv2 is described in RFC 1905, and is similar to that of SNMPv1. The format for all PDUs in SNMPv2 is the same, except for the GetBulkRequest-PDU message. (Oddly, this includes the Trapv2-PDU message, even though the Trap-PDU message in SNMPv1 used a distinct format).

SNMPv2 Common PDU Format

Table 218 and Figure 283 show this common PDU format. Table 219 contains a listing of the different values for the Error Status field and how they are interpreted.


Table 218: SNMP Version 2 (SNMPv2) Common PDU Format

Field Name

Syntax

Size (bytes)

Description

PDU Type

Integer (Enumerated)

4

 

Request ID

Integer

4

Request Identifier: A number used to match requests with replies. It is generated by the device that sends a request and copied into this field in a Response-PDU by the responding SNMP entity.

Error Status

Integer (Enumerated)

4

Error Status: An integer value that is used in a Response-PDU to tell the requesting SNMP entity the result of its request. A value of zero indicates that no error occurred; the other values indicate what sort of error happened.

Note that the first six values (0 to 5) are maintained as used in SNMPv1 for compatibility, but SNMPv2 adds many new error codes that provide more specific indication of the exact nature of an error in a request. The genErr code is still used only when none of specific error types (either the old codes or the new ones) apply.

Since there are so many different Error Status codes, I have listed them separately in
Table 219.

Error Index

Integer

4

Error Index: When Error Status is non-zero, this field contains a pointer that specifies which object generated the error. Always zero in a request.

Variable Bindings

Variable

Variable

Variable Bindings: A set of name-value pairs identifying the MIB objects in the PDU, and in the case of messages other than requests, containing their values. See the general message format topic for more on these bindings.



Table 219: SNMP Version 2 (SNMPv2) PDU Error Status Field Values

Error Status Value

Error Code

Description

0

noError

No error occurred. This code is also used in all request PDUs, since they have no error status to report.

1

tooBig

The size of the Response-PDU would be too large to transport.

2

noSuchName

The name of a requested object was not found.

3

badValue

A value in the request didn't match the structure that the recipient of the request had for the object. For example, an object in the request was specified with an incorrect length or type.

4

readOnly

An attempt was made to set a variable that has an Access value indicating that it is read-only.

5

genErr

An error occurred other than one indicated by a more specific error code in this table.

6

noAccess

Access was denied to the object for security reasons.

7

wrongType

The object type in a variable binding is incorrect for the object.

8

wrongLength

A variable binding specifies a length incorrect for the object.

9

wrongEncoding

A variable binding specifies an encoding incorrect for the object.

10

wrongValue

The value given in a variable binding is not possible for the object.

11

noCreation

A specified variable does not exist and cannot be created.

12

inconsistentValue

A variable binding specifies a value that could be held by the variable but cannot be assigned to it at this time.

13

resourceUnavailable

An attempt to set a variable required a resource that is not available.

14

commitFailed

An attempt to set a particular variable failed.

15

undoFailed

An attempt to set a particular variable as part of a group of variables failed, and the attempt to then undo the setting of other variables was not successful.

16

authorizationError

A problem occurred in authorization.

17

notWritable

The variable cannot be written or created.

18

inconsistentName

The name in a variable binding specifies a variable that does not exist.



Figure 283: SNMP Version 2 (SNMPv2) Common PDU Format

 


Previous Topic/Section
SNMP Version 1 (SNMPv1) Message Format
Previous Page
Pages in Current Topic/Section
1234
5
6
Next Page
SNMP Version 3 (SNMPv3) Message Format
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005

Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.