Nokia IPSO 4.0 manual Configuring SNMPv3, GetNextRequest, GetBulkRequest, 262

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Value Field Set	Description
genErr	If the processing of a variable fails for any other reason, the responding entity returns
	genErr and a value in the error-index field that is the index of the problem object in the
	variable-bindings field.
tooBig	If the size of the message that encapsulates the generated response PDU exceeds a
	local limitation or the maximum message size of the request’s source party, then the
	response PDU is discarded and a new response PDU is constructed. The new
	response PDU has an error-status of tooBig, an error-indexof zero, and an empty
	variable-bindings field.

GetNextRequest

The only values that can be returned as the second element in the variable-bindings field to a GetNextRequest when an error-status code occurs are unSpecified or endOfMibView.

GetBulkRequest

The GetBulkRequest minimizes the number of protocol exchanges by letting an SNMPv2 manager request that the response be as large as possible given the constraints on the message size.

The GetBulkRequest PDU has two fields that do not appear in the other PDUs: non-repeaters and max-repetitions. The non-repeaters field specifies the number of variables in the variable- bindings list for which a single-lexicographic successor is to be returned. The max-repetitions field specifies the number of lexicographic successors to be returned for the remaining variables in the variable-bindings list.

If at any point in the process, a lexicographic successor does not exist, the endofMibView value is returned with the name of the last lexicographic successor, or, if there were no successors, the name of the variable in the request.

If the processing of a variable name fails for any reason other than endofMibView, no values are returned. Instead, the responding entity returns a response PDU with an error-status of genErr and a value in the error-index field that is the index of the problem object in the variable- bindings field.

Configuring SNMPv3

IPSO supports the user-based security model (USM) component of SNMPv3 to provide message-level security. With USM (described in RFC 3414), access to the SNMP service is controlled on the basis of user identities. Each user has a name, an authentication pass phrase (used for identifying the user), and an optional privacy pass phrase (used for cryptographically protecting against disclosure of SNMP message payloads).

The system uses the MD5 hashing algorithm to provide authentication and integrity protection and DES to provide encryption (privacy). Nokia recommends that you use both authentication

262 Nokia Network Voyager for IPSO 4.0 Reference Guide