Definitions of Managed Objects for IEEE 802.3 Medium Attachment Units (MAUs) using SMIv2
obsoleted by
- rfc-2668 — Definitions of Managed Objects for IEEE 802.3 Medium Attachment Units (MAUs)
Extracted elements (26)
The mauRpGrpBasic and mauIfGrpBasic conformance groups are explicitly noted to also serve as the conformance specification for RFC 1515 implementations, enabling backward compatibility verification without requiring a separate compliance statement.
This MIB is designed as a superset of RFC 1515, which is moved to historic status. It retains all RFC 1515 objects and adds support for 100 Mb/s devices, auto-negotiation on interface MAUs, and jack management, allowing a smooth migration path for existing implementations.
An agent implementing repeater-MAU objects must also implement the 802.3 Repeater MIB (RFC 2108). The rpMauGroupIndex and rpMauPortIndex values must match rptrPortGroupIndex and rptrPortIndex for the corresponding repeater port.
An agent implementing the interface-MAU related objects must also implement the 'interfaces' group of MIB-II; the value of ifMauIfIndex must equal the ifIndex value for the connected interface. Repeater ports are not represented as MIB-II interfaces.
Where an IEEE 802.3u-1995 clause 22 MII is present, a logic one in the remote fault bit maps to remoteFault(5) and a logic zero in the link status bit maps to notAvailable(4) in the mediaAvailable object; notAvailable(4) takes precedence over remoteFault(5).
An agent implementing the mauModIfCompl compliance must implement mauIfGrpAutoNeg for MAUs with managed auto-negotiation, and mauBroadBasic for broadband MAUs; these groups are mandatory (not optional) within the interface compliance statement.
The agent must throttle consecutive rpMauJabberTrap (and ifMauJabberTrap) notifications so that there is at least a five-second gap between them to prevent notification flooding.
When ifMauAutoNegAdminStatus transitions from enabled to disabled, the agent must ensure that ifMauType correctly transitions to the value of ifMauDefaultType, rather than continuing to reflect the auto-negotiated value.
ifMauAutoNegCapability and ifMauAutoNegCapAdvertised encode auto-negotiation technology abilities as bitmasks (powers of 2 assigned per capability type: bits 10-11 for 10BASE-T HD/FD, bits 14-20 for 100BASE variants). Capabilities in ifMauAutoNegCapAdvertised that are absent from ifMauAutoNegCapability cannot be enabled.
ifMauAutoNegRemoteSignaling indicates whether the remote end uses auto-negotiation; it is detected(1) only if FLP Bursts were received during the previous link negotiation, otherwise notdetected(2).
ifMauAutoNegRestart is a read-write object; setting it to restart(1) forces link renegotiation. Setting to norestart(2) has no effect. A write has no effect if auto-negotiation signaling is disabled.
ifMauDefaultType is a read-write OBJECT IDENTIFIER identifying the administratively configured MAU type. When auto-negotiation is disabled, this value determines the operational MAU type (ifMauType); when auto-negotiation is re-disabled after being enabled, the MAU must revert to this type.
ifMauTypeList encodes the set of MAU type capabilities as a bitmask Integer32, where bit position n corresponds to a specific MAU type (e.g., bit 9 = 10BASE-T HD, bit 16 = 100BASE-TX FD). If auto-negotiation is present, this object maps to ifMauAutoNegCapability.
rpMauFalseCarriers (and ifMauFalseCarriers) counts false carrier events during IDLE on 100BASE-X links, incrementing at most once per 100 ms after a valid carrier completion. This counter applies only to dot3MauType100BaseT4, 100BaseTX, and 100BaseFX; approximate rollover time is 7.4 hours.
rpMauJabberState (and ifMauJabberState) reports jabber condition with values: other(1), unknown(2), noJabber(3), jabbering(4). Agents must always return other(1) for MAU type dot3MauTypeAUI; for AUI/100BASE-T4/TX/FX, the jabberingStateEnters counter always reads zero.
rpMauJabberTrap and ifMauJabberTrap are NOTIFICATION-TYPEs sent when a managed MAU enters the jabber state. Agents must throttle consecutive jabber traps so there is at least a five-second gap between them.
rpMauMediaAvailable (and ifMauMediaAvailable) reports link/loopback status with values: other(1), unknown(2), available(3), notAvailable(4), remoteFault(5), invalidSignal(6), remoteJabber(7), remoteLinkLoss(8), remoteTest(9). For 100BASE-T4/TX/FX these map to states in IEEE 802.3u link integrity state diagrams.
The broadMauBasicTable covers 10BROAD36 broadband MAUs attached to interfaces, providing xmit/receive split type (single or dual cable), transmit carrier frequency, and translation offset frequency (both in units of MHz/4, i.e., 250 kHz).
The ifMauAutoNegTable provides per-MAU auto-negotiation configuration and status, including admin status (enabled/disabled), remote signaling detection, configuration state (configuring/complete/disabled/parallelDetectFail), local capability, advertised capability, received capability, and restart control.
The JackType TEXTUAL-CONVENTION enumerates physical connector types used by both repeater and interface MAU jack tables: other(1), rj45(2), rj45S(3), db9(4), bnc(5), fAUI(6), mAUI(7), fiberSC(8), fiberMIC(9), fiberST(10), telco(11).
The MAU-MIB module is registered at snmpDot3MauMgt (mib-2 26), with the module identity mauMod at { snmpDot3MauMgt 6 }. It defines managed objects for 10 and 100 Mb/s IEEE 802.3 MAUs based on IEEE Std 802.3u-1995 Section 30.
The rpMauTable (dot3RpMauBasicGroup 1) contains per-MAU status for repeater-attached MAUs, indexed by rpMauGroupIndex, rpMauPortIndex, and rpMauIndex, and includes type, status, media availability, jabber state, and counters.
Twenty MAU type OBJECT-IDENTITIEs are defined under dot3MauType (snmpDot3MauMgt 4), covering AUI, 10BASE-5/2/T/FP/FB/FL/Broad36 and 100BASE-T4/TX/FX/T2 variants with half/full duplex distinctions. New assignments are managed by IANA.
New MAU type OBJECT-IDENTIFIERs under dot3MauType (snmpDot3MauMgt 4) are assigned by IANA. If the MAU type is unknown, the reserved identifier { 0 0 } (unknownMauType) is returned; all conformant ASN.1/BER implementations must generate and recognize this value.
Several writable MIB objects can significantly affect network operation, including enabling/disabling MAUs, changing default MAU type, and modifying auto-negotiation capabilities. Implementers are recommended to require at minimum authentication of request origin before permitting set operations on this MIB.
rpMauStatus (and ifMauStatus) defines MAU administrative states: other(1), unknown(2), operational(3), standby(4), shutdown(5), reset(6). Writing reset(6) causes a power-cycle equivalent reset; setting a mixing-type MAU or AUI to standby(4) causes it to enter shutdown instead.