IEEE8021-CFM-V2-MIB

InterfaceIndexA unique value, greater than zero, for each interface or interface sub-layer in the managed system. It is recommended that values are assigned contiguously starting from 1. The value for each interface sub-layer must remain constant at least from one re-initialization of the entity's network management system to the next re-initialization. (1..2147483647) · Integer32 · hint d

Reference: 12.14.2.1.2:a

This object represents the Bridge Port or aggregated port on which MEPs or MHFs might be configured. Upon a restart of the system, the system SHALL, if necessary, change the value of this variable, and rearrange the ieee8021CfmStackTable, so that it indexes the entry in the interface table with the same value of ifAlias that it indexed before the system restart. If no such entry exists, then the system SHALL delete all entries in the ieee8021CfmStackTable with the interface index.

IEEE8021ServiceSelectorType1 = vlanId2 = isid3 = tesid4 = segid5 = path-tesid6 = group-isid7 = ieeeReservedA value that represents a type (and thereby the format) of a IEEE8021ServiceSelectorValue. The value can be one of the following: ieeeReserved(0) Reserved for definition by IEEE 802.1 recommend to not use zero unless absolutely needed. vlanId(1) 12-Bit identifier as described in IEEE Std 802.1Q. isid(2) 24-Bit identifier as described in IEEE Std 802.1ah. tesid(3) 32 Bit identifier as described below. segid(4) 32 Bit identifier as described below. path-tesid(5) 32 Bit identifier as described below. group-isid(6) 24 Bit identifier as described below. ieeeReserved(7) Reserved for definition by IEEE Std 802.1 To support future extensions, the IEEE8021ServiceSelectorType textual convention SHOULD NOT be subtyped in object type definitions. It MAY be subtyped in compliance statements in order to require only a subset of these address types for a compliant implementation. The tesid is used as a service selector for MAs that are present in Bridges that implement PBB-TE functionality. A selector of this type is interpreted as a 32 bit unsigned value of type IEEE8021PbbTeTSidId. This type is used to index the ieee8021PbbTeTeSiEspTable to find the ESPs which comprise the TE Service Instance named by this TE-SID value. The segid is used as a service selector for MAs that are present in Bridges that implement IPS functionality. A selector of this type is interpreted as a 32 bit unsigned value of type IEEE8021TeipsSegid. This type is used to index the Ieee8021TeipsSegTable to find the SMPs which comprise the Infrastructure Segment named by this segid value. The path-tesid is used as a service selector for SPBM path MAs. A selector of this type is interpreted as a 32 bit unsigned value corresponding to the MA index dot1agCfmMaIndex. This type is used to index the dot1agCfmMepSpbmEspTable to find the ESPs which comprise the SPBM path associated with an SPBM path MA. The group-isid is used as a service selector for SPBM group MAs. A selector of this type is interpreted as a 24 bit unsigned value corresponding to the I-SID associated with an SPBM group MA. Implementations MUST ensure that IEEE8021ServiceSelectorType objects and any dependent objects (e.g., IEEE8021ServiceSelectorValue objects) are consistent. An inconsistentValue error MUST be generated if an attempt to change an IEEE8021ServiceSelectorType object would, for example, lead to an undefined IEEE8021ServiceSelectorValue value. · Integer32

Reference: 12.14.2.1.2:d, 22.1.7

Type of the Service Selector identifier indicated by ieee8021CfmStackServiceSelectorOrNone. See textual convention IEEE8021ServiceSelectorType for details.

IEEE8021ServiceSelectorValueOrNoneAn integer that uniquely identifies a generic MAC Service, or none. Examples of service selectors are a VLAN-ID (IEEE 802.1Q) and an I-SID (IEEE Std 802.1ah). An IEEE8021ServiceSelectorValueOrNone value is always interpreted within the context of an IEEE8021ServiceSelectorType value. Every usage of the IEEE8021ServiceSelectorValueOrNone textual convention is required to specify the IEEE8021ServiceSelectorType object that provides the context. It is suggested that the IEEE8021ServiceSelectorType object be logically registered before the object(s) that use the IEEE8021ServiceSelectorValueOrNone textual convention, if they appear in the same logical row. The value of an IEEE8021ServiceSelectorValueOrNone object must always be consistent with the value of the associated IEEE8021ServiceSelectorType object. Attempts to set an IEEE8021ServiceSelectorValueOrNone object to a value inconsistent with the associated IEEE8021ServiceSelectorType must fail with an inconsistentValue error. The special value of zero is used to indicate that no service selector is present or used. This can be used in any situation where an object or a table entry MUST either refer to a specific service, or not make a selection. Note that a MIB object that is defined using this TEXTUAL-CONVENTION SHOULD clarify the meaning of 'no service' (i.e., the special value 0), as well as the maximum value (i.e., 4094, for a VLAN ID). (0 | 1..4294967295) · Unsigned32 · hint d

Reference: 12.14.2.1.2:d, 22.1.7

Service Selector identifier to which the MP is attached, or 0, if none. See textual convention IEEE8021ServiceSelectorValue for details.

Dot1agCfmMDLevelInteger identifying the Maintenance Domain Level (MD Level). Higher numbers correspond to higher Maintenance Domains, those with the greatest physical reach, with the highest values for customers' CFM PDUs. Lower numbers correspond to lower Maintenance Domains, those with more limited physical reach, with the lowest values for CFM PDUs protecting single Bridges or physical links.Reference: 18.3, 21.4.1 (0..7) · Integer32 · hint d

Reference: 12.14.2.1.2:b

MD Level of the Maintenance Point.

Dot1agCfmMpDirection1 = down2 = upIndicates the direction in which the Maintenance association (MEP or MIP) faces on the Bridge Port: down(1) Sends Continuity Check Messages away from the MAC Relay Entity. up(2) Sends Continuity Check Messages towards the MAC Relay Entity.Reference: 12.14.6.3.2:c · Integer32

Reference: 12.14.2.1.2:c

Direction in which the MP faces on the Bridge Port.

Unsigned32

Reference: 12.14.2.1.3:b

The index of the Maintenance Domain in the ieee8021CfmMdTable to which the MP is associated, or 0, if none.

Unsigned32

Reference: 12.14.2.1.3:c

The index of the MA in the ieee8021CfmMaNetTable and ieee8021CfmMaCompTable to which the MP is associated, or 0, if none.

Dot1agCfmMepIdOrZeroMaintenance association Endpoint Identifier (MEPID): A small integer, unique over a given Maintenance Association, identifying a specific MEP. The special value 0 is allowed to indicate special cases, for example that no MEPID is configured. Whenever an object is defined with this SYNTAX, then the DESCRIPTION clause of such an object MUST specify what the special value of 0 means.Reference: 19.2.1 (0 | 1..8191) · Unsigned32 · hint d

Reference: 12.14.2.1.3:d

If an MEP is configured, the MEPID, else 0

MacAddressRepresents an 802 MAC address represented in the `canonical' order defined by IEEE 802.1a, i.e., as if it were transmitted least significant bit first, even though 802.5 (in contrast to other 802.x protocols) requires MAC addresses to be transmitted most significant bit first. SIZE (6) · OCTET STRING · hint 1x:

Reference: 12.14.2.1.3:e

MAC address of the MP.

IEEE8021PbbComponentIdentifierThe component identifier is used to distinguish between the multiple virtual Bridge instances within a PB or PBB. Each virtual Bridge instance is called a component. In simple situations where there is only a single component the default value is 1. The component is identified by a component identifier unique within the BEB and by a MAC address unique within the PBBN. Each component is associated with a Backbone Edge Bridge (BEB) Configuration managed object.Reference: 12.3 l) (1..4294967295) · Unsigned32 · hint d

Reference: 12.3 l)

The bridge component within the system to which the information in this ieee8021CfmDefaultMdEntry applies. If the system is not a Bridge, or if only one component is present in the Bridge, then this variable (index) MUST be equal to 1.

IEEE8021ServiceSelectorType1 = vlanId2 = isid3 = tesid4 = segid5 = path-tesid6 = group-isid7 = ieeeReservedA value that represents a type (and thereby the format) of a IEEE8021ServiceSelectorValue. The value can be one of the following: ieeeReserved(0) Reserved for definition by IEEE 802.1 recommend to not use zero unless absolutely needed. vlanId(1) 12-Bit identifier as described in IEEE Std 802.1Q. isid(2) 24-Bit identifier as described in IEEE Std 802.1ah. tesid(3) 32 Bit identifier as described below. segid(4) 32 Bit identifier as described below. path-tesid(5) 32 Bit identifier as described below. group-isid(6) 24 Bit identifier as described below. ieeeReserved(7) Reserved for definition by IEEE Std 802.1 To support future extensions, the IEEE8021ServiceSelectorType textual convention SHOULD NOT be subtyped in object type definitions. It MAY be subtyped in compliance statements in order to require only a subset of these address types for a compliant implementation. The tesid is used as a service selector for MAs that are present in Bridges that implement PBB-TE functionality. A selector of this type is interpreted as a 32 bit unsigned value of type IEEE8021PbbTeTSidId. This type is used to index the ieee8021PbbTeTeSiEspTable to find the ESPs which comprise the TE Service Instance named by this TE-SID value. The segid is used as a service selector for MAs that are present in Bridges that implement IPS functionality. A selector of this type is interpreted as a 32 bit unsigned value of type IEEE8021TeipsSegid. This type is used to index the Ieee8021TeipsSegTable to find the SMPs which comprise the Infrastructure Segment named by this segid value. The path-tesid is used as a service selector for SPBM path MAs. A selector of this type is interpreted as a 32 bit unsigned value corresponding to the MA index dot1agCfmMaIndex. This type is used to index the dot1agCfmMepSpbmEspTable to find the ESPs which comprise the SPBM path associated with an SPBM path MA. The group-isid is used as a service selector for SPBM group MAs. A selector of this type is interpreted as a 24 bit unsigned value corresponding to the I-SID associated with an SPBM group MA. Implementations MUST ensure that IEEE8021ServiceSelectorType objects and any dependent objects (e.g., IEEE8021ServiceSelectorValue objects) are consistent. An inconsistentValue error MUST be generated if an attempt to change an IEEE8021ServiceSelectorType object would, for example, lead to an undefined IEEE8021ServiceSelectorValue value. · Integer32

Type of the Primary Service Selector identifier indicated by ieee8021CfmDefaultMdPrimarySelector. See textual convention IEEE8021ServiceSelectorType for details.

IEEE8021ServiceSelectorValueAn integer that uniquely identifies a generic MAC Service. Examples of service selectors are a VLAN-ID (IEEE 802.1Q) and an I-SID (IEEE Std 802.1ah). An IEEE8021ServiceSelectorValue value is always interpreted within the context of an IEEE8021ServiceSelectorType value. Every usage of the IEEE8021ServiceSelectorValue textual convention is required to specify the IEEE8021ServiceSelectorType object that provides the context. It is suggested that the IEEE8021ServiceSelectorType object be logically registered before the object(s) that use the IEEE8021ServiceSelectorValue textual convention, if they appear in the same logical row. The value of an IEEE8021ServiceSelectorValue object must always be consistent with the value of the associated IEEE8021ServiceSelectorType object. Attempts to set an IEEE8021ServiceSelectorValue object to a value inconsistent with the associated IEEE8021ServiceSelectorType must fail with an inconsistentValue error. Note that a MIB object that is defined using this TEXTUAL-CONVENTION SHOULD clarify the maximum value (i.e., 4094, for a VLAN ID). (1..4294967295) · Unsigned32 · hint d

Primary Service Selector identifier of a Service Instance with no MA configured. See IEEE8021ServiceSelectorValue for details.

TruthValue1 = true2 = falseRepresents a boolean value. · Integer32

Reference: 12.14.3.1.3:b

State of this Default MD Level table entry. True if there is no entry in the Maintenance Association table defining an MA for the same VLAN ID and MD Level as this table's entry, and on which MA an Up MEP is defined, else false.

Dot1agCfmMDLevelOrNoneInteger identifying the Maintenance Domain Level (MD Level). Higher numbers correspond to higher Maintenance Domains, those with the greatest physical reach, with the highest values for customers' CFM packets. Lower numbers correspond to lower Maintenance Domains, those with more limited physical reach, with the lowest values for CFM PDUs protecting single Bridges or physical links. The value (-1) is reserved to indicate that no MA Level has been assigned.Reference: 18.3, 12.14.3.1.3:c (-1 | 0..7) · Integer32 · hint d

Reference: 12.14.3.1.3:c, 12.14.3.2.2:b

A value indicating the MD Level at which MHFs are to be created, and Sender ID TLV transmission by those MHFs is to be controlled, for the VLAN to which this entry's objects apply. If this object has the value -1, the MD Level for MHF creation for this VLAN is controlled by ieee8021CfmDefaultMdDefLevel.

Dot1agCfmMhfCreation1 = defMHFnone2 = defMHFdefault3 = defMHFexplicit4 = defMHFdeferIndicates if the Management Entity can create MHFs. The valid values are: defMHFnone(1) No MHFs can be created for this VID. defMHFdefault(2) MHFs can be created on this VID on any Bridge port through which this VID can pass. defMHFexplicit(3) MHFs can be created for this VID only on Bridge ports through which this VID can pass, and only if a MEP is created at some lower MD Level. defMHFdefer(4) The creation of MHFs is determined by the corresponding Maintenance Domain variable (dot1agCfmMaCompMhfCreation).Reference: 12.14.5.1.3:c, 22.2.3 · Integer32

Reference: 12.14.3.1.3:d

A value indicating if the Management entity can create MHFs (MIP Half Function) for this VID at this MD Level. If this object has the value defMHFdefer, MHF creation for this VLAN is controlled by ieee8021CfmDefaultMdDefMhfCreation. The value of this variable is meaningless if the values of ieee8021CfmDefaultMdStatus is false.

Dot1agCfmIdPermission1 = sendIdNone2 = sendIdChassis3 = sendIdManage4 = sendIdChassisManage5 = sendIdDeferIndicates what, if anything, is to be included in the Sender ID TLV transmitted in CCMs, LBMs, LTMs, and LTRs. The valid values are: sendIdNone(1) The Sender ID TLV is not to be sent. sendIdChassis(2) The Chassis ID Length, Chassis ID Subtype, and Chassis ID fields of the Sender ID TLV are to be sent. sendIdManage(3) The Management Address Length and Management Address of the Sender ID TLV are to be sent. sendIdChassisManage(4) The Chassis ID Length, Chassis ID Subtype, Chassis ID, Management Address Length and Management Address fields are all to be sent. sendIdDefer(5) The contents of the Sender ID TLV are determined by the corresponding Maintenance Domain variable (dot1agCfmMaCompIdPermission).Reference: 12.14.6.1.3:d, 21.5.3 · Integer32

Reference: 12.14.3.1.3:e

Enumerated value indicating what, if anything, is to be included in the Sender ID TLV (21.5.3) transmitted by MHFs created by the Default Maintenance Domain. If this object has the value sendIdDefer, Sender ID TLV transmission for this VLAN is controlled by ieee8021CfmDefaultMdDefIdPermission. The value of this variable is meaningless if the values of ieee8021CfmDefaultMdStatus is false.

IEEE8021PbbComponentIdentifierThe component identifier is used to distinguish between the multiple virtual Bridge instances within a PB or PBB. Each virtual Bridge instance is called a component. In simple situations where there is only a single component the default value is 1. The component is identified by a component identifier unique within the BEB and by a MAC address unique within the PBBN. Each component is associated with a Backbone Edge Bridge (BEB) Configuration managed object.Reference: 12.3 l) (1..4294967295) · Unsigned32 · hint d

Reference: 12.3 l)

The bridge component within the system to which the information in this ieee8021CfmVlanEntry applies. If the system is not a Bridge, or if only one component is present in the Bridge, then this variable (index) MUST be equal to 1.

IEEE8021ServiceSelectorValueAn integer that uniquely identifies a generic MAC Service. Examples of service selectors are a VLAN-ID (IEEE 802.1Q) and an I-SID (IEEE Std 802.1ah). An IEEE8021ServiceSelectorValue value is always interpreted within the context of an IEEE8021ServiceSelectorType value. Every usage of the IEEE8021ServiceSelectorValue textual convention is required to specify the IEEE8021ServiceSelectorType object that provides the context. It is suggested that the IEEE8021ServiceSelectorType object be logically registered before the object(s) that use the IEEE8021ServiceSelectorValue textual convention, if they appear in the same logical row. The value of an IEEE8021ServiceSelectorValue object must always be consistent with the value of the associated IEEE8021ServiceSelectorType object. Attempts to set an IEEE8021ServiceSelectorValue object to a value inconsistent with the associated IEEE8021ServiceSelectorType must fail with an inconsistentValue error. Note that a MIB object that is defined using this TEXTUAL-CONVENTION SHOULD clarify the maximum value (i.e., 4094, for a VLAN ID). (1..4294967295) · Unsigned32 · hint d

This is a service ID belonging to a service that is associated with more than one Service Selector identifiers, and this is not the Primary Service ID of the service. The type of this Service Selector is the same as the primary Service Selector's type defined by ieee8021CfmMaCompPrimarySelectorType in the ieee8021CfmMaCompTable.

IEEE8021ServiceSelectorValueAn integer that uniquely identifies a generic MAC Service. Examples of service selectors are a VLAN-ID (IEEE 802.1Q) and an I-SID (IEEE Std 802.1ah). An IEEE8021ServiceSelectorValue value is always interpreted within the context of an IEEE8021ServiceSelectorType value. Every usage of the IEEE8021ServiceSelectorValue textual convention is required to specify the IEEE8021ServiceSelectorType object that provides the context. It is suggested that the IEEE8021ServiceSelectorType object be logically registered before the object(s) that use the IEEE8021ServiceSelectorValue textual convention, if they appear in the same logical row. The value of an IEEE8021ServiceSelectorValue object must always be consistent with the value of the associated IEEE8021ServiceSelectorType object. Attempts to set an IEEE8021ServiceSelectorValue object to a value inconsistent with the associated IEEE8021ServiceSelectorType must fail with an inconsistentValue error. Note that a MIB object that is defined using this TEXTUAL-CONVENTION SHOULD clarify the maximum value (i.e., 4094, for a VLAN ID). (1..4294967295) · Unsigned32 · hint d

This is the Primary Service selector for a Service that is associated with more than one Service Selector identifiers. This value MUST not equal the value of ieee8021CfmVlanSelector. The type of this Service Selector is the same as the primary Service Selector's type defined by ieee8021CfmMaCompPrimarySelectorType in the ieee8021CfmMaCompTable.

RowStatus1 = active2 = notInService3 = notReady4 = createAndGo5 = createAndWait6 = destroyThe RowStatus textual convention is used to manage the creation and deletion of conceptual rows, and is used as the value of the SYNTAX clause for the status column of a conceptual row (as described in Section 7.7.1 of [2].) The status column has six defined values: - `active', which indicates that the conceptual row is available for use by the managed device; - `notInService', which indicates that the conceptual row exists in the agent, but is unavailable for use by the managed device (see NOTE below); 'notInService' has no implication regarding the internal consistency of the row, availability of resources, or consistency with the current state of the managed device; - `notReady', which indicates that the conceptual row exists in the agent, but is missing information necessary in order to be available for use by the managed device (i.e., one or more required columns in the conceptual row have not been instanciated); - `createAndGo', which is supplied by a management station wishing to create a new instance of a conceptual row and to have its status automatically set to active, making it available for use by the managed device; - `createAndWait', which is supplied by a management station wishing to create a new instance of a conceptual row (but not make it available for use by the managed device); and, - `destroy', which is supplied by a management station wishing to delete all of the instances associated with an existing conceptual row. Whereas five of the six values (all except `notReady') may be specified in a management protocol set operation, only three values will be returned in response to a management protocol retrieval operation: `notReady', `notInService' or `active'. That is, when queried, an existing conceptual row has only three states: it is either available for use by the managed device (the status column has value `active'); it is not available for use by the managed device, though the agent has sufficient information to attempt to make it so (the status column has value `notInService'); or, it is not available for use by the managed device, and an attempt to make it so would fail because the agent has insufficient information (the state column has value `notReady'). NOTE WELL This textual convention may be used for a MIB table, irrespective of whether the values of that table's conceptual rows are able to be modified while it is active, or whether its conceptual rows must be taken out of service in order to be modified. That is, it is the responsibility of the DESCRIPTION clause of the status column to specify whether the status column must not be `active' in order for the value of some other column of the same conceptual row to be modified. If such a specification is made, affected columns may be changed by an SNMP set PDU if the RowStatus would not be equal to `active' either immediately before or after processing the PDU. In other words, if the PDU also contained a varbind that would change the RowStatus value, the column in question may be changed if the RowStatus was not equal to `active' as the PDU was received, or if the varbind sets the status to a value other than 'active'. Also note that whenever any elements of a row exist, the RowStatus column must also exist. To summarize the effect of having a conceptual row with a status column having a SYNTAX clause value of RowStatus, consider the following state diagram: STATE +--------------+-----------+-------------+------------- | A | B | C | D | |status col.|status column| |status column | is | is |status column ACTION |does not exist| notReady | notInService| is active --------------+--------------+-----------+-------------+------------- set status |noError ->D|inconsist- |inconsistent-|inconsistent- column to | or | entValue| Value| Value createAndGo |inconsistent- | | | | Value| | | --------------+--------------+-----------+-------------+------------- set status |noError see 1|inconsist- |inconsistent-|inconsistent- column to | or | entValue| Value| Value createAndWait |wrongValue | | | --------------+--------------+-----------+-------------+------------- set status |inconsistent- |inconsist- |noError |noError column to | Value| entValue| | active | | | | | | or | | | | | | | |see 2 ->D|see 8 ->D| ->D --------------+--------------+-----------+-------------+------------- set status |inconsistent- |inconsist- |noError |noError ->C column to | Value| entValue| | notInService | | | | | | or | | or | | | | | |see 3 ->C| ->C|see 6 --------------+--------------+-----------+-------------+------------- set status |noError |noError |noError |noError ->A column to | | | | or destroy | ->A| ->A| ->A|see 7 --------------+--------------+-----------+-------------+------------- set any other |see 4 |noError |noError |see 5 column to some| | | | value | | see 1| ->C| ->D --------------+--------------+-----------+-------------+------------- (1) goto B or C, depending on information available to the agent. (2) if other variable bindings included in the same PDU, provide values for all columns which are missing but required, and all columns have acceptable values, then return noError and goto D. (3) if other variable bindings included in the same PDU, provide legal values for all columns which are missing but required, then return noError and goto C. (4) at the discretion of the agent, the return value may be either: inconsistentName: because the agent does not choose to create such an instance when the corresponding RowStatus instance does not exist, or inconsistentValue: if the supplied value is inconsistent with the state of some other MIB object's value, or noError: because the agent chooses to create the instance. If noError is returned, then the instance of the status column must also be created, and the new state is B or C, depending on the information available to the agent. If inconsistentName or inconsistentValue is returned, the row remains in state A. (5) depending on the MIB definition for the column/table, either noError or inconsistentValue may be returned. (6) the return value can indicate one of the following errors: wrongValue: because the agent does not support notInService (e.g., an agent which does not support createAndWait), or inconsistentValue: because the agent is unable to take the row out of service at this time, perhaps because it is in use and cannot be de-activated. (7) the return value can indicate the following error: inconsistentValue: because the agent is unable to remove the row at this time, perhaps because it is in use and cannot be de-activated. (8) the transition to D can fail, e.g., if the values of the conceptual row are inconsistent, then the error code would be inconsistentValue. NOTE: Other processing of (this and other varbinds of) the set request may result in a response other than noError being returned, e.g., wrongValue, noCreation, etc. Conceptual Row Creation There are four potential interactions when creating a conceptual row: selecting an instance-identifier which is not in use; creating the conceptual row; initializing any objects for which the agent does not supply a default; and, making the conceptual row available for use by the managed device. Interaction 1: Selecting an Instance-Identifier The algorithm used to select an instance-identifier varies for each conceptual row. In some cases, the instance- identifier is semantically significant, e.g., the destination address of a route, and a management station selects the instance-identifier according to the semantics. In other cases, the instance-identifier is used solely to distinguish conceptual rows, and a management station without specific knowledge of the conceptual row might examine the instances present in order to determine an unused instance-identifier. (This approach may be used, but it is often highly sub-optimal; however, it is also a questionable practice for a naive management station to attempt conceptual row creation.) Alternately, the MIB module which defines the conceptual row might provide one or more objects which provide assistance in determining an unused instance-identifier. For example, if the conceptual row is indexed by an integer-value, then an object having an integer-valued SYNTAX clause might be defined for such a purpose, allowing a management station to issue a management protocol retrieval operation. In order to avoid unnecessary collisions between competing management stations, `adjacent' retrievals of this object should be different. Finally, the management station could select a pseudo-random number to use as the index. In the event that this index was already in use and an inconsistentValue was returned in response to the management protocol set operation, the management station should simply select a new pseudo-random number and retry the operation. A MIB designer should choose between the two latter algorithms based on the size of the table (and therefore the efficiency of each algorithm). For tables in which a large number of entries are expected, it is recommended that a MIB object be defined that returns an acceptable index for creation. For tables with small numbers of entries, it is recommended that the latter pseudo-random index mechanism be used. Interaction 2: Creating the Conceptual Row Once an unused instance-identifier has been selected, the management station determines if it wishes to create and activate the conceptual row in one transaction or in a negotiated set of interactions. Interaction 2a: Creating and Activating the Conceptual Row The management station must first determine the column requirements, i.e., it must determine those columns for which it must or must not provide values. Depending on the complexity of the table and the management station's knowledge of the agent's capabilities, this determination can be made locally by the management station. Alternately, the management station issues a management protocol get operation to examine all columns in the conceptual row that it wishes to create. In response, for each column, there are three possible outcomes: - a value is returned, indicating that some other management station has already created this conceptual row. We return to interaction 1. - the exception `noSuchInstance' is returned, indicating that the agent implements the object-type associated with this column, and that this column in at least one conceptual row would be accessible in the MIB view used by the retrieval were it to exist. For those columns to which the agent provides read-create access, the `noSuchInstance' exception tells the management station that it should supply a value for this column when the conceptual row is to be created. - the exception `noSuchObject' is returned, indicating that the agent does not implement the object-type associated with this column or that there is no conceptual row for which this column would be accessible in the MIB view used by the retrieval. As such, the management station can not issue any management protocol set operations to create an instance of this column. Once the column requirements have been determined, a management protocol set operation is accordingly issued. This operation also sets the new instance of the status column to `createAndGo'. When the agent processes the set operation, it verifies that it has sufficient information to make the conceptual row available for use by the managed device. The information available to the agent is provided by two sources: the management protocol set operation which creates the conceptual row, and, implementation-specific defaults supplied by the agent (note that an agent must provide implementation-specific defaults for at least those objects which it implements as read-only). If there is sufficient information available, then the conceptual row is created, a `noError' response is returned, the status column is set to `active', and no further interactions are necessary (i.e., interactions 3 and 4 are skipped). If there is insufficient information, then the conceptual row is not created, and the set operation fails with an error of `inconsistentValue'. On this error, the management station can issue a management protocol retrieval operation to determine if this was because it failed to specify a value for a required column, or, because the selected instance of the status column already existed. In the latter case, we return to interaction 1. In the former case, the management station can re-issue the set operation with the additional information, or begin interaction 2 again using `createAndWait' in order to negotiate creation of the conceptual row. NOTE WELL Regardless of the method used to determine the column requirements, it is possible that the management station might deem a column necessary when, in fact, the agent will not allow that particular columnar instance to be created or written. In this case, the management protocol set operation will fail with an error such as `noCreation' or `notWritable'. In this case, the management station decides whether it needs to be able to set a value for that particular columnar instance. If not, the management station re-issues the management protocol set operation, but without setting a value for that particular columnar instance; otherwise, the management station aborts the row creation algorithm. Interaction 2b: Negotiating the Creation of the Conceptual Row The management station issues a management protocol set operation which sets the desired instance of the status column to `createAndWait'. If the agent is unwilling to process a request of this sort, the set operation fails with an error of `wrongValue'. (As a consequence, such an agent must be prepared to accept a single management protocol set operation, i.e., interaction 2a above, containing all of the columns indicated by its column requirements.) Otherwise, the conceptual row is created, a `noError' response is returned, and the status column is immediately set to either `notInService' or `notReady', depending on whether it has sufficient information to (attempt to) make the conceptual row available for use by the managed device. If there is sufficient information available, then the status column is set to `notInService'; otherwise, if there is insufficient information, then the status column is set to `notReady'. Regardless, we proceed to interaction 3. Interaction 3: Initializing non-defaulted Objects The management station must now determine the column requirements. It issues a management protocol get operation to examine all columns in the created conceptual row. In the response, for each column, there are three possible outcomes: - a value is returned, indicating that the agent implements the object-type associated with this column and had sufficient information to provide a value. For those columns to which the agent provides read-create access (and for which the agent allows their values to be changed after their creation), a value return tells the management station that it may issue additional management protocol set operations, if it desires, in order to change the value associated with this column. - the exception `noSuchInstance' is returned, indicating that the agent implements the object-type associated with this column, and that this column in at least one conceptual row would be accessible in the MIB view used by the retrieval were it to exist. However, the agent does not have sufficient information to provide a value, and until a value is provided, the conceptual row may not be made available for use by the managed device. For those columns to which the agent provides read-create access, the `noSuchInstance' exception tells the management station that it must issue additional management protocol set operations, in order to provide a value associated with this column. - the exception `noSuchObject' is returned, indicating that the agent does not implement the object-type associated with this column or that there is no conceptual row for which this column would be accessible in the MIB view used by the retrieval. As such, the management station can not issue any management protocol set operations to create an instance of this column. If the value associated with the status column is `notReady', then the management station must first deal with all `noSuchInstance' columns, if any. Having done so, the value of the status column becomes `notInService', and we proceed to interaction 4. Interaction 4: Making the Conceptual Row Available Once the management station is satisfied with the values associated with the columns of the conceptual row, it issues a management protocol set operation to set the status column to `active'. If the agent has sufficient information to make the conceptual row available for use by the managed device, the management protocol set operation succeeds (a `noError' response is returned). Otherwise, the management protocol set operation fails with an error of `inconsistentValue'. NOTE WELL A conceptual row having a status column with value `notInService' or `notReady' is unavailable to the managed device. As such, it is possible for the managed device to create its own instances during the time between the management protocol set operation which sets the status column to `createAndWait' and the management protocol set operation which sets the status column to `active'. In this case, when the management protocol set operation is issued to set the status column to `active', the values held in the agent supersede those used by the managed device. If the management station is prevented from setting the status column to `active' (e.g., due to management station or network failure) the conceptual row will be left in the `notInService' or `notReady' state, consuming resources indefinitely. The agent must detect conceptual rows that have been in either state for an abnormally long period of time and remove them. It is the responsibility of the DESCRIPTION clause of the status column to indicate what an abnormally long period of time would be. This period of time should be long enough to allow for human response time (including `think time') between the creation of the conceptual row and the setting of the status to `active'. In the absence of such information in the DESCRIPTION clause, it is suggested that this period be approximately 5 minutes in length. This removal action applies not only to newly-created rows, but also to previously active rows which are set to, and left in, the notInService state for a prolonged period exceeding that which is considered normal for such a conceptual row. Conceptual Row Suspension When a conceptual row is `active', the management station may issue a management protocol set operation which sets the instance of the status column to `notInService'. If the agent is unwilling to do so, the set operation fails with an error of `wrongValue' or `inconsistentValue'. Otherwise, the conceptual row is taken out of service, and a `noError' response is returned. It is the responsibility of the DESCRIPTION clause of the status column to indicate under what circumstances the status column should be taken out of service (e.g., in order for the value of some other column of the same conceptual row to be modified). Conceptual Row Deletion For deletion of conceptual rows, a management protocol set operation is issued which sets the instance of the status column to `destroy'. This request may be made regardless of the current value of the status column (e.g., it is possible to delete conceptual rows which are either `notReady', `notInService' or `active'.) If the operation succeeds, then all instances associated with the conceptual row are immediately removed. · Integer32

The status of the row. The writable columns in a row can not be changed if the row is active. All columns MUST have a valid value before a row can be activated.

IEEE8021ServiceSelectorType1 = vlanId2 = isid3 = tesid4 = segid5 = path-tesid6 = group-isid7 = ieeeReservedA value that represents a type (and thereby the format) of a IEEE8021ServiceSelectorValue. The value can be one of the following: ieeeReserved(0) Reserved for definition by IEEE 802.1 recommend to not use zero unless absolutely needed. vlanId(1) 12-Bit identifier as described in IEEE Std 802.1Q. isid(2) 24-Bit identifier as described in IEEE Std 802.1ah. tesid(3) 32 Bit identifier as described below. segid(4) 32 Bit identifier as described below. path-tesid(5) 32 Bit identifier as described below. group-isid(6) 24 Bit identifier as described below. ieeeReserved(7) Reserved for definition by IEEE Std 802.1 To support future extensions, the IEEE8021ServiceSelectorType textual convention SHOULD NOT be subtyped in object type definitions. It MAY be subtyped in compliance statements in order to require only a subset of these address types for a compliant implementation. The tesid is used as a service selector for MAs that are present in Bridges that implement PBB-TE functionality. A selector of this type is interpreted as a 32 bit unsigned value of type IEEE8021PbbTeTSidId. This type is used to index the ieee8021PbbTeTeSiEspTable to find the ESPs which comprise the TE Service Instance named by this TE-SID value. The segid is used as a service selector for MAs that are present in Bridges that implement IPS functionality. A selector of this type is interpreted as a 32 bit unsigned value of type IEEE8021TeipsSegid. This type is used to index the Ieee8021TeipsSegTable to find the SMPs which comprise the Infrastructure Segment named by this segid value. The path-tesid is used as a service selector for SPBM path MAs. A selector of this type is interpreted as a 32 bit unsigned value corresponding to the MA index dot1agCfmMaIndex. This type is used to index the dot1agCfmMepSpbmEspTable to find the ESPs which comprise the SPBM path associated with an SPBM path MA. The group-isid is used as a service selector for SPBM group MAs. A selector of this type is interpreted as a 24 bit unsigned value corresponding to the I-SID associated with an SPBM group MA. Implementations MUST ensure that IEEE8021ServiceSelectorType objects and any dependent objects (e.g., IEEE8021ServiceSelectorValue objects) are consistent. An inconsistentValue error MUST be generated if an attempt to change an IEEE8021ServiceSelectorType object would, for example, lead to an undefined IEEE8021ServiceSelectorValue value. · Integer32

Reference: 12.14.4.1.2:a

Type of the Service Selector identifier indicated by ieee8021CfmConfigErrorListSelector. See textual convention IEEE8021ServiceSelectorType for details.

IEEE8021ServiceSelectorValueAn integer that uniquely identifies a generic MAC Service. Examples of service selectors are a VLAN-ID (IEEE 802.1Q) and an I-SID (IEEE Std 802.1ah). An IEEE8021ServiceSelectorValue value is always interpreted within the context of an IEEE8021ServiceSelectorType value. Every usage of the IEEE8021ServiceSelectorValue textual convention is required to specify the IEEE8021ServiceSelectorType object that provides the context. It is suggested that the IEEE8021ServiceSelectorType object be logically registered before the object(s) that use the IEEE8021ServiceSelectorValue textual convention, if they appear in the same logical row. The value of an IEEE8021ServiceSelectorValue object must always be consistent with the value of the associated IEEE8021ServiceSelectorType object. Attempts to set an IEEE8021ServiceSelectorValue object to a value inconsistent with the associated IEEE8021ServiceSelectorType must fail with an inconsistentValue error. Note that a MIB object that is defined using this TEXTUAL-CONVENTION SHOULD clarify the maximum value (i.e., 4094, for a VLAN ID). (1..4294967295) · Unsigned32 · hint d

Reference: 12.14.4.1.2:a

The Service Selector Identifier of the Service with interfaces in error. See IEEE8021ServiceSelectorValue for details.

InterfaceIndexA unique value, greater than zero, for each interface or interface sub-layer in the managed system. It is recommended that values are assigned contiguously starting from 1. The value for each interface sub-layer must remain constant at least from one re-initialization of the entity's network management system to the next re-initialization. (1..2147483647) · Integer32 · hint d

Reference: 12.14.4.1.2:b

This object is the IfIndex of the interface. Upon a restart of the system, the system SHALL, if necessary, change the value of this variable so that it indexes the entry in the interface table with the same value of ifAlias that it indexed before the system restart. If no such entry exists, then the system SHALL delete any entries in ieee8021CfmConfigErrorListTable indexed by that InterfaceIndex value.

Dot1agCfmConfigErrorsWhile making the MIP creation evaluation described in 22.2.3, the management entity can encounter errors in the configuration. These are possible errors that can be encountered: CFMleak(0) MA x is associated with a specific VID list, one or more of the VIDs in MA x can pass through the Bridge Port, no Down MEP is configured on any Bridge Port for MA x, and some other MA y, at a higher MD Level than MA x, and associated with at least one of the VID(s) also in MA x, does have a MEP configured on the Bridge Port. conflictingVids(1) MA x is associated with a specific VID list, an Up MEP is configured on MA x on the Bridge Port, and some other MA y, associated with at least one of the VID(s) also in MA x, also has an Up MEP configured on some Bridge Port. ExcessiveLevels(2) The number of different MD Levels at which MIPs are to be created on this port exceeds the Bridge's capabilities (22.3). OverlappedLevels(3) A MEP is created for one VID at one MD Level, but a MEP is configured on another VID at that MD Level or higher, exceeding the Bridge's capabilities.Reference: 12.14.4.1.3:b, 22.2.3, 22.2.4 · BITS

Reference: 12.14.4.1.3:b

A vector of Boolean error conditions from 22.2.4, any of which may be true: 0) CFMleak; 1) ConflictingVids; 2) ExcessiveLevels; 3) OverlappedLevels.

IEEE8021PbbComponentIdentifierThe component identifier is used to distinguish between the multiple virtual Bridge instances within a PB or PBB. Each virtual Bridge instance is called a component. In simple situations where there is only a single component the default value is 1. The component is identified by a component identifier unique within the BEB and by a MAC address unique within the PBBN. Each component is associated with a Backbone Edge Bridge (BEB) Configuration managed object.Reference: 12.3 l) (1..4294967295) · Unsigned32 · hint d

Reference: 12.3 l)

The bridge component within the system to which the information in this ieee8021CfmMaCompEntry applies. If the system is not a Bridge, or if only one component is present in the Bridge, then this variable (index) MUST be equal to 1.

IEEE8021ServiceSelectorType1 = vlanId2 = isid3 = tesid4 = segid5 = path-tesid6 = group-isid7 = ieeeReservedA value that represents a type (and thereby the format) of a IEEE8021ServiceSelectorValue. The value can be one of the following: ieeeReserved(0) Reserved for definition by IEEE 802.1 recommend to not use zero unless absolutely needed. vlanId(1) 12-Bit identifier as described in IEEE Std 802.1Q. isid(2) 24-Bit identifier as described in IEEE Std 802.1ah. tesid(3) 32 Bit identifier as described below. segid(4) 32 Bit identifier as described below. path-tesid(5) 32 Bit identifier as described below. group-isid(6) 24 Bit identifier as described below. ieeeReserved(7) Reserved for definition by IEEE Std 802.1 To support future extensions, the IEEE8021ServiceSelectorType textual convention SHOULD NOT be subtyped in object type definitions. It MAY be subtyped in compliance statements in order to require only a subset of these address types for a compliant implementation. The tesid is used as a service selector for MAs that are present in Bridges that implement PBB-TE functionality. A selector of this type is interpreted as a 32 bit unsigned value of type IEEE8021PbbTeTSidId. This type is used to index the ieee8021PbbTeTeSiEspTable to find the ESPs which comprise the TE Service Instance named by this TE-SID value. The segid is used as a service selector for MAs that are present in Bridges that implement IPS functionality. A selector of this type is interpreted as a 32 bit unsigned value of type IEEE8021TeipsSegid. This type is used to index the Ieee8021TeipsSegTable to find the SMPs which comprise the Infrastructure Segment named by this segid value. The path-tesid is used as a service selector for SPBM path MAs. A selector of this type is interpreted as a 32 bit unsigned value corresponding to the MA index dot1agCfmMaIndex. This type is used to index the dot1agCfmMepSpbmEspTable to find the ESPs which comprise the SPBM path associated with an SPBM path MA. The group-isid is used as a service selector for SPBM group MAs. A selector of this type is interpreted as a 24 bit unsigned value corresponding to the I-SID associated with an SPBM group MA. Implementations MUST ensure that IEEE8021ServiceSelectorType objects and any dependent objects (e.g., IEEE8021ServiceSelectorValue objects) are consistent. An inconsistentValue error MUST be generated if an attempt to change an IEEE8021ServiceSelectorType object would, for example, lead to an undefined IEEE8021ServiceSelectorValue value. · Integer32

Reference: 12.14.6.1.3:b

Type of the Service Selector identifiers indicated by ieee8021CfmMaCompPrimarySelectorOrNone. If the service instance is defined by more than one Service Selector, this parameter also indicates the type of the ieee8021CfmVlanPrimarySelector and ieee8021CfmVlanSelector in the ieee8021CfmVlanTable. In Services instances made of multiple Service Selector identifiers, ensures that the type of the Service selector identifiers is the same. See textual convention Dot1agCfmServiceSelectorType for details.

IEEE8021ServiceSelectorValueOrNoneAn integer that uniquely identifies a generic MAC Service, or none. Examples of service selectors are a VLAN-ID (IEEE 802.1Q) and an I-SID (IEEE Std 802.1ah). An IEEE8021ServiceSelectorValueOrNone value is always interpreted within the context of an IEEE8021ServiceSelectorType value. Every usage of the IEEE8021ServiceSelectorValueOrNone textual convention is required to specify the IEEE8021ServiceSelectorType object that provides the context. It is suggested that the IEEE8021ServiceSelectorType object be logically registered before the object(s) that use the IEEE8021ServiceSelectorValueOrNone textual convention, if they appear in the same logical row. The value of an IEEE8021ServiceSelectorValueOrNone object must always be consistent with the value of the associated IEEE8021ServiceSelectorType object. Attempts to set an IEEE8021ServiceSelectorValueOrNone object to a value inconsistent with the associated IEEE8021ServiceSelectorType must fail with an inconsistentValue error. The special value of zero is used to indicate that no service selector is present or used. This can be used in any situation where an object or a table entry MUST either refer to a specific service, or not make a selection. Note that a MIB object that is defined using this TEXTUAL-CONVENTION SHOULD clarify the meaning of 'no service' (i.e., the special value 0), as well as the maximum value (i.e., 4094, for a VLAN ID). (0 | 1..4294967295) · Unsigned32 · hint d

Reference: 12.14.6.1.3:b

Service Selector identifier to which the MP is attached, or 0, if none. If the MA is associated with more than one Service Selectors Identifiers, the ieee8021CfmVlanTable lists them.

Dot1agCfmMhfCreation1 = defMHFnone2 = defMHFdefault3 = defMHFexplicit4 = defMHFdeferIndicates if the Management Entity can create MHFs. The valid values are: defMHFnone(1) No MHFs can be created for this VID. defMHFdefault(2) MHFs can be created on this VID on any Bridge port through which this VID can pass. defMHFexplicit(3) MHFs can be created for this VID only on Bridge ports through which this VID can pass, and only if a MEP is created at some lower MD Level. defMHFdefer(4) The creation of MHFs is determined by the corresponding Maintenance Domain variable (dot1agCfmMaCompMhfCreation).Reference: 12.14.5.1.3:c, 22.2.3 · Integer32

Reference: 12.14.6.1.3:c

Indicates if the Management entity can create MHFs (MIP Half Function) for this MA.

Dot1agCfmIdPermission1 = sendIdNone2 = sendIdChassis3 = sendIdManage4 = sendIdChassisManage5 = sendIdDeferIndicates what, if anything, is to be included in the Sender ID TLV transmitted in CCMs, LBMs, LTMs, and LTRs. The valid values are: sendIdNone(1) The Sender ID TLV is not to be sent. sendIdChassis(2) The Chassis ID Length, Chassis ID Subtype, and Chassis ID fields of the Sender ID TLV are to be sent. sendIdManage(3) The Management Address Length and Management Address of the Sender ID TLV are to be sent. sendIdChassisManage(4) The Chassis ID Length, Chassis ID Subtype, Chassis ID, Management Address Length and Management Address fields are all to be sent. sendIdDefer(5) The contents of the Sender ID TLV are determined by the corresponding Maintenance Domain variable (dot1agCfmMaCompIdPermission).Reference: 12.14.6.1.3:d, 21.5.3 · Integer32

Reference: 12.14.6.1.3:d

Enumerated value indicating what, if anything, is to be included in the Sender ID TLV (21.5.3) transmitted by MPs configured in this MA.

Unsigned32

Reference: 12.14.6.1.3:b

The number of VIDs associated with the MA.

RowStatus1 = active2 = notInService3 = notReady4 = createAndGo5 = createAndWait6 = destroyThe RowStatus textual convention is used to manage the creation and deletion of conceptual rows, and is used as the value of the SYNTAX clause for the status column of a conceptual row (as described in Section 7.7.1 of [2].) The status column has six defined values: - `active', which indicates that the conceptual row is available for use by the managed device; - `notInService', which indicates that the conceptual row exists in the agent, but is unavailable for use by the managed device (see NOTE below); 'notInService' has no implication regarding the internal consistency of the row, availability of resources, or consistency with the current state of the managed device; - `notReady', which indicates that the conceptual row exists in the agent, but is missing information necessary in order to be available for use by the managed device (i.e., one or more required columns in the conceptual row have not been instanciated); - `createAndGo', which is supplied by a management station wishing to create a new instance of a conceptual row and to have its status automatically set to active, making it available for use by the managed device; - `createAndWait', which is supplied by a management station wishing to create a new instance of a conceptual row (but not make it available for use by the managed device); and, - `destroy', which is supplied by a management station wishing to delete all of the instances associated with an existing conceptual row. Whereas five of the six values (all except `notReady') may be specified in a management protocol set operation, only three values will be returned in response to a management protocol retrieval operation: `notReady', `notInService' or `active'. That is, when queried, an existing conceptual row has only three states: it is either available for use by the managed device (the status column has value `active'); it is not available for use by the managed device, though the agent has sufficient information to attempt to make it so (the status column has value `notInService'); or, it is not available for use by the managed device, and an attempt to make it so would fail because the agent has insufficient information (the state column has value `notReady'). NOTE WELL This textual convention may be used for a MIB table, irrespective of whether the values of that table's conceptual rows are able to be modified while it is active, or whether its conceptual rows must be taken out of service in order to be modified. That is, it is the responsibility of the DESCRIPTION clause of the status column to specify whether the status column must not be `active' in order for the value of some other column of the same conceptual row to be modified. If such a specification is made, affected columns may be changed by an SNMP set PDU if the RowStatus would not be equal to `active' either immediately before or after processing the PDU. In other words, if the PDU also contained a varbind that would change the RowStatus value, the column in question may be changed if the RowStatus was not equal to `active' as the PDU was received, or if the varbind sets the status to a value other than 'active'. Also note that whenever any elements of a row exist, the RowStatus column must also exist. To summarize the effect of having a conceptual row with a status column having a SYNTAX clause value of RowStatus, consider the following state diagram: STATE +--------------+-----------+-------------+------------- | A | B | C | D | |status col.|status column| |status column | is | is |status column ACTION |does not exist| notReady | notInService| is active --------------+--------------+-----------+-------------+------------- set status |noError ->D|inconsist- |inconsistent-|inconsistent- column to | or | entValue| Value| Value createAndGo |inconsistent- | | | | Value| | | --------------+--------------+-----------+-------------+------------- set status |noError see 1|inconsist- |inconsistent-|inconsistent- column to | or | entValue| Value| Value createAndWait |wrongValue | | | --------------+--------------+-----------+-------------+------------- set status |inconsistent- |inconsist- |noError |noError column to | Value| entValue| | active | | | | | | or | | | | | | | |see 2 ->D|see 8 ->D| ->D --------------+--------------+-----------+-------------+------------- set status |inconsistent- |inconsist- |noError |noError ->C column to | Value| entValue| | notInService | | | | | | or | | or | | | | | |see 3 ->C| ->C|see 6 --------------+--------------+-----------+-------------+------------- set status |noError |noError |noError |noError ->A column to | | | | or destroy | ->A| ->A| ->A|see 7 --------------+--------------+-----------+-------------+------------- set any other |see 4 |noError |noError |see 5 column to some| | | | value | | see 1| ->C| ->D --------------+--------------+-----------+-------------+------------- (1) goto B or C, depending on information available to the agent. (2) if other variable bindings included in the same PDU, provide values for all columns which are missing but required, and all columns have acceptable values, then return noError and goto D. (3) if other variable bindings included in the same PDU, provide legal values for all columns which are missing but required, then return noError and goto C. (4) at the discretion of the agent, the return value may be either: inconsistentName: because the agent does not choose to create such an instance when the corresponding RowStatus instance does not exist, or inconsistentValue: if the supplied value is inconsistent with the state of some other MIB object's value, or noError: because the agent chooses to create the instance. If noError is returned, then the instance of the status column must also be created, and the new state is B or C, depending on the information available to the agent. If inconsistentName or inconsistentValue is returned, the row remains in state A. (5) depending on the MIB definition for the column/table, either noError or inconsistentValue may be returned. (6) the return value can indicate one of the following errors: wrongValue: because the agent does not support notInService (e.g., an agent which does not support createAndWait), or inconsistentValue: because the agent is unable to take the row out of service at this time, perhaps because it is in use and cannot be de-activated. (7) the return value can indicate the following error: inconsistentValue: because the agent is unable to remove the row at this time, perhaps because it is in use and cannot be de-activated. (8) the transition to D can fail, e.g., if the values of the conceptual row are inconsistent, then the error code would be inconsistentValue. NOTE: Other processing of (this and other varbinds of) the set request may result in a response other than noError being returned, e.g., wrongValue, noCreation, etc. Conceptual Row Creation There are four potential interactions when creating a conceptual row: selecting an instance-identifier which is not in use; creating the conceptual row; initializing any objects for which the agent does not supply a default; and, making the conceptual row available for use by the managed device. Interaction 1: Selecting an Instance-Identifier The algorithm used to select an instance-identifier varies for each conceptual row. In some cases, the instance- identifier is semantically significant, e.g., the destination address of a route, and a management station selects the instance-identifier according to the semantics. In other cases, the instance-identifier is used solely to distinguish conceptual rows, and a management station without specific knowledge of the conceptual row might examine the instances present in order to determine an unused instance-identifier. (This approach may be used, but it is often highly sub-optimal; however, it is also a questionable practice for a naive management station to attempt conceptual row creation.) Alternately, the MIB module which defines the conceptual row might provide one or more objects which provide assistance in determining an unused instance-identifier. For example, if the conceptual row is indexed by an integer-value, then an object having an integer-valued SYNTAX clause might be defined for such a purpose, allowing a management station to issue a management protocol retrieval operation. In order to avoid unnecessary collisions between competing management stations, `adjacent' retrievals of this object should be different. Finally, the management station could select a pseudo-random number to use as the index. In the event that this index was already in use and an inconsistentValue was returned in response to the management protocol set operation, the management station should simply select a new pseudo-random number and retry the operation. A MIB designer should choose between the two latter algorithms based on the size of the table (and therefore the efficiency of each algorithm). For tables in which a large number of entries are expected, it is recommended that a MIB object be defined that returns an acceptable index for creation. For tables with small numbers of entries, it is recommended that the latter pseudo-random index mechanism be used. Interaction 2: Creating the Conceptual Row Once an unused instance-identifier has been selected, the management station determines if it wishes to create and activate the conceptual row in one transaction or in a negotiated set of interactions. Interaction 2a: Creating and Activating the Conceptual Row The management station must first determine the column requirements, i.e., it must determine those columns for which it must or must not provide values. Depending on the complexity of the table and the management station's knowledge of the agent's capabilities, this determination can be made locally by the management station. Alternately, the management station issues a management protocol get operation to examine all columns in the conceptual row that it wishes to create. In response, for each column, there are three possible outcomes: - a value is returned, indicating that some other management station has already created this conceptual row. We return to interaction 1. - the exception `noSuchInstance' is returned, indicating that the agent implements the object-type associated with this column, and that this column in at least one conceptual row would be accessible in the MIB view used by the retrieval were it to exist. For those columns to which the agent provides read-create access, the `noSuchInstance' exception tells the management station that it should supply a value for this column when the conceptual row is to be created. - the exception `noSuchObject' is returned, indicating that the agent does not implement the object-type associated with this column or that there is no conceptual row for which this column would be accessible in the MIB view used by the retrieval. As such, the management station can not issue any management protocol set operations to create an instance of this column. Once the column requirements have been determined, a management protocol set operation is accordingly issued. This operation also sets the new instance of the status column to `createAndGo'. When the agent processes the set operation, it verifies that it has sufficient information to make the conceptual row available for use by the managed device. The information available to the agent is provided by two sources: the management protocol set operation which creates the conceptual row, and, implementation-specific defaults supplied by the agent (note that an agent must provide implementation-specific defaults for at least those objects which it implements as read-only). If there is sufficient information available, then the conceptual row is created, a `noError' response is returned, the status column is set to `active', and no further interactions are necessary (i.e., interactions 3 and 4 are skipped). If there is insufficient information, then the conceptual row is not created, and the set operation fails with an error of `inconsistentValue'. On this error, the management station can issue a management protocol retrieval operation to determine if this was because it failed to specify a value for a required column, or, because the selected instance of the status column already existed. In the latter case, we return to interaction 1. In the former case, the management station can re-issue the set operation with the additional information, or begin interaction 2 again using `createAndWait' in order to negotiate creation of the conceptual row. NOTE WELL Regardless of the method used to determine the column requirements, it is possible that the management station might deem a column necessary when, in fact, the agent will not allow that particular columnar instance to be created or written. In this case, the management protocol set operation will fail with an error such as `noCreation' or `notWritable'. In this case, the management station decides whether it needs to be able to set a value for that particular columnar instance. If not, the management station re-issues the management protocol set operation, but without setting a value for that particular columnar instance; otherwise, the management station aborts the row creation algorithm. Interaction 2b: Negotiating the Creation of the Conceptual Row The management station issues a management protocol set operation which sets the desired instance of the status column to `createAndWait'. If the agent is unwilling to process a request of this sort, the set operation fails with an error of `wrongValue'. (As a consequence, such an agent must be prepared to accept a single management protocol set operation, i.e., interaction 2a above, containing all of the columns indicated by its column requirements.) Otherwise, the conceptual row is created, a `noError' response is returned, and the status column is immediately set to either `notInService' or `notReady', depending on whether it has sufficient information to (attempt to) make the conceptual row available for use by the managed device. If there is sufficient information available, then the status column is set to `notInService'; otherwise, if there is insufficient information, then the status column is set to `notReady'. Regardless, we proceed to interaction 3. Interaction 3: Initializing non-defaulted Objects The management station must now determine the column requirements. It issues a management protocol get operation to examine all columns in the created conceptual row. In the response, for each column, there are three possible outcomes: - a value is returned, indicating that the agent implements the object-type associated with this column and had sufficient information to provide a value. For those columns to which the agent provides read-create access (and for which the agent allows their values to be changed after their creation), a value return tells the management station that it may issue additional management protocol set operations, if it desires, in order to change the value associated with this column. - the exception `noSuchInstance' is returned, indicating that the agent implements the object-type associated with this column, and that this column in at least one conceptual row would be accessible in the MIB view used by the retrieval were it to exist. However, the agent does not have sufficient information to provide a value, and until a value is provided, the conceptual row may not be made available for use by the managed device. For those columns to which the agent provides read-create access, the `noSuchInstance' exception tells the management station that it must issue additional management protocol set operations, in order to provide a value associated with this column. - the exception `noSuchObject' is returned, indicating that the agent does not implement the object-type associated with this column or that there is no conceptual row for which this column would be accessible in the MIB view used by the retrieval. As such, the management station can not issue any management protocol set operations to create an instance of this column. If the value associated with the status column is `notReady', then the management station must first deal with all `noSuchInstance' columns, if any. Having done so, the value of the status column becomes `notInService', and we proceed to interaction 4. Interaction 4: Making the Conceptual Row Available Once the management station is satisfied with the values associated with the columns of the conceptual row, it issues a management protocol set operation to set the status column to `active'. If the agent has sufficient information to make the conceptual row available for use by the managed device, the management protocol set operation succeeds (a `noError' response is returned). Otherwise, the management protocol set operation fails with an error of `inconsistentValue'. NOTE WELL A conceptual row having a status column with value `notInService' or `notReady' is unavailable to the managed device. As such, it is possible for the managed device to create its own instances during the time between the management protocol set operation which sets the status column to `createAndWait' and the management protocol set operation which sets the status column to `active'. In this case, when the management protocol set operation is issued to set the status column to `active', the values held in the agent supersede those used by the managed device. If the management station is prevented from setting the status column to `active' (e.g., due to management station or network failure) the conceptual row will be left in the `notInService' or `notReady' state, consuming resources indefinitely. The agent must detect conceptual rows that have been in either state for an abnormally long period of time and remove them. It is the responsibility of the DESCRIPTION clause of the status column to indicate what an abnormally long period of time would be. This period of time should be long enough to allow for human response time (including `think time') between the creation of the conceptual row and the setting of the status to `active'. In the absence of such information in the DESCRIPTION clause, it is suggested that this period be approximately 5 minutes in length. This removal action applies not only to newly-created rows, but also to previously active rows which are set to, and left in, the notInService state for a prolonged period exceeding that which is considered normal for such a conceptual row. Conceptual Row Suspension When a conceptual row is `active', the management station may issue a management protocol set operation which sets the instance of the status column to `notInService'. If the agent is unwilling to do so, the set operation fails with an error of `wrongValue' or `inconsistentValue'. Otherwise, the conceptual row is taken out of service, and a `noError' response is returned. It is the responsibility of the DESCRIPTION clause of the status column to indicate under what circumstances the status column should be taken out of service (e.g., in order for the value of some other column of the same conceptual row to be modified). Conceptual Row Deletion For deletion of conceptual rows, a management protocol set operation is issued which sets the instance of the status column to `destroy'. This request may be made regardless of the current value of the status column (e.g., it is possible to delete conceptual rows which are either `notReady', `notInService' or `active'.) If the operation succeeds, then all instances associated with the conceptual row are immediately removed. · Integer32

The status of the row. The writable columns in a row can not be changed if the row is active. All columns MUST have a valid value before a row can be activated.