The Response-PDU is generated by a SNMPv2 entity only upon receipt of a GetRequest-PDU, GetNextRequest-PDU, GetBulkRequest-PDU, SetRequest-PDU, or InformRequest-PDU, as described elsewhere in this document.
If the error-status field of the Response-PDU is non-zero, the value fields of the variable bindings in the variable binding list are ignored.
If both the error-status field and the error-index field of the Response-PDU are non-zero, then the value of the error-index field is the index of the variable binding (in the variable-binding list of the corresponding request) for which the request failed. The first variable binding in a request's variable-binding list is index one, the second is index two, etc. A compliant SNMPv2 entity acting in a manager role must be able to properly receive and handle a Response-PDU with an error-status field equal to `noSuchName', `badValue', or `readOnly'. (See Section 3.1.2 of [8].)
Upon receipt of a Response-PDU, the receiving SNMPv2 entity presents its contents to the SNMPv2 application which generated the request with the same request-id value.