Definitions of Managed Objects for SNA NAUs using SMIv2
obsoleted by
- rfc-1666 — Definitions of Managed Objects for SNA NAUs using SMIv2
Extracted elements (26)
Each Admin and Oper table has a companion LastChange TimeStamp object (e.g., snaNodeAdminTableLastChange). A Management Station polls only this scalar; a changed value signals that a full table retrieval is warranted, avoiding unnecessary bulk retrievals of large tables.
The MIB deliberately excludes LU 6.2-specific objects and covers only the generic objects common to all LU types, citing that LU 6.2 specifics warrant a separate module. Similarly, link creation and activation/deactivation of LUs and sessions are out of scope, delegated to the SNA DLC MIB.
The MIB splits configuration and runtime data into parallel Admin and Oper tables. Admin tables hold desired/configured values (read-create) while Oper tables (augmenting Admin) hold actual runtime values (read-only). This separation makes it explicit which values are targets versus current reality, and allows the Agent to be the sole writer to Oper entries.
Link-specific configuration and operation (e.g., SDLC link parameters) are managed through the SNA DLC MIB module, not this MIB. snaNodeLinkAdminSpecific and snaNodeLinkOperSpecific use InstancePointer to reference the sdlcLSAdminTable and sdlcLSOperTable in the DLC MIB.
This MIB module does not support creation of links, activation or deactivation of LUs, or activation of sessions. Only Node (PU) activation/deactivation and session deactivation via AdminState are within scope.
A Management Station may set snaNodeAdminRowStatus to 'destroy (6)' only when snaNodeOperState of that Node instance is 'inactive (1)'. The Agent then deletes the corresponding rows from both snaNodeAdminTable and snaNodeOperTable.
An Agent that does not implement row creation for snaNodeAdminTable, snaNodeLinkAdminTable, or snaLuAdminTable must at minimum support object modification requests (read-write access rather than read-create).
Conformance mandates three unconditionally required groups: snaNodeGroup, snaLuGroup, and snaSessionGroup. snaPu20Group is mandatory only for entities implementing PU type 2.0; snaMgtToolsRtmGroup is mandatory only for entities implementing LU type 2 with RTM.
For LU 6.2, the only valid termination method value for snaLuAdminTerm and snaNodeAdminLuTermDefault is 'unbind (1)'. Setting other values is invalid for LU 6.2 instances.
The Agent automatically deletes rows with RowStatus equal to 'notReady (3)' if they remain in that state for more than a default period of 5 minutes. Additionally, all 'notReady' rows are removed upon the next SNA services initialization.
Upon successful creation of an snaNodeAdminTable row, the Agent automatically creates a corresponding entry in snaNodeOperTable with snaNodeOperState set to 'inactive (1)'. The same pattern applies for snaLuAdminTable rows creating snaLuOperTable entries.
Write operations to most snaNodeAdmin and snaLuAdmin objects do not take effect (i.e., do not change the corresponding Oper object values) until the Node has been re-activated. Exceptions include snaNodeAdminEnablingMethod (may change immediately for demand↔onlyMS transitions) and snaNodeAdminHostDescription.
Four SNMP traps are defined: snaNodeStateChangeTrap (Node OperState changed, carrying snaNodeOperName and snaNodeOperState), snaNodeActFailTrap (ACTPU failure, also carrying snaNodeOperActFailureReason), snaLuStateChangeTrap (LU state change), and snaLuSessnBindFailTrap (BIND request failure).
snaLuAdminTable contains read-create LU configuration indexed by snaNodeAdminIndex and snaLuAdminLuIndex. Fields include LU type (lu0 through lu7 plus lu62), dependency type (dependent/independent), local address (1-byte OCTET STRING), display model (model2A through model5B plus dynamic, valid only for LU type 2), and termination method.
snaLuSessnTable contains read-only LU-LU session operational state; entries are created by the Agent when a session reaches 'pending-bind (2)' and removed when it reaches 'unbound (1)'. Indexed by Node, Link, LU, and session indices.
snaNodeAdminTable contains read-create configuration parameters for SNA Nodes (PU types 1.0, 2.0, 2.1). It includes snaNodeAdminState (desired state), snaNodeAdminRowStatus (row lifecycle), node type, XID format, block number, ID number, enabling method, LU termination default, max LUs, host description, and stop method.
snaNodeLinkAdminTable associates Node instances with link instances via InstancePointer (snaNodeLinkAdminSpecific pointing to sdlcLSAdminTable ifIndex in the SNA DLC MIB) and snaNodeLinkAdminMaxPiu (maximum PIU size in octets). Indexed by snaNodeAdminIndex and snaNodeLinkAdminIndex to support multiple links per Node.
snaNodeOperTable augments snaNodeAdminTable and contains read-only runtime values mirroring Admin objects plus additional operational fields: snaNodeOperState (inactive/active/waiting/stopping), snaNodeOperHostSscpId (PU 2.0 only, up to 6 octets), snaNodeOperStartTime, snaNodeOperLastStateChange, snaNodeOperActFailures, and snaNodeOperActFailureReason.
snaPu20StatsTable provides read-only PU 2.0 statistics indexed by snaNodeAdminIndex, including Counter32 fields for sent/received bytes and PIUs, sent/received negative responses, and Gauge32 fields for active LUs (snaPu20StatsActLus), inactive LUs (snaPu20StatsInActLus), and BINDed LUs (snaPu20StatsBindLus).
The SNANAU MIB is divided into three object groups: snaNode (Node/PU configuration, monitoring, control), snaLu (LU definition, monitoring, control), and snaMgtTools (optional RTM statistics). Objects within each group are further organized into Admin and Oper tables.
The snanauMIB MODULE-IDENTITY is registered at { mib-2 34 }, placing the SNA NAU MIB within MIB-II's object tree. All SNANAU managed objects are rooted under this OID.
Several objects in the SNANAU MIB have read-create or read-write access; improper use could cause disruption of network services. Implementations should apply the SNMPv2 security mechanisms defined in RFC 1445 to restrict access to sensitive objects such as snaNodeAdminState and RowStatus objects.
Node OperState transitions: inactive→active (AdminState set to active), active→stopping (AdminState set to inactive with normal/immed stop method), active→waiting (activation pending), waiting→inactive (activation failed or aborted), stopping→inactive (shutdown complete). A newly created Admin row causes the Agent to set OperState to 'inactive'.
Session OperState transitions: entry created at 'pending-bind (2)', advances to 'bound (3)' on successful BIND, enters 'pending-unbind (4)' when unbind is in progress, and is removed from the table when it reaches 'unbound (1)'. Setting AdminState to 'unbound' from any state causes transition to 'unbound'.
snaLuAdminLocalAddress is a 1-byte OCTET STRING (SIZE(1)) representing the LU's local address. For dependent LUs the value ranges from 1 to 254; for independent LUs the value is always 0.
The SNA Node ID is split across two DisplayString fields: snaNodeAdminBlockNum (SIZE(3)) holds the first 3 hexadecimal digits, and snaNodeAdminIdNum (SIZE(5)) holds the last 5 hexadecimal digits. snaNodeOperHostSscpId is an OCTET STRING of SIZE(0..6) for the SSCP identifier on PU 2.0 nodes.