Definitions of Managed Objects for IEEE 802.3 Medium Attachment Units (MAUs)
obsoleted by
- rfc-4836 — Definitions of Managed Objects for IEEE 802.3 Medium Attachment Units (MAUs)
obsoletes
Extracted elements (26)
A 64-bit counter ifMauHCFalseCarriers was added alongside the existing 32-bit ifMauFalseCarriers because the 32-bit counter can roll over in as little as ~7.4 hours on 100BASE-X links, risking loss of information between polling intervals. Management stations are advised to poll the HC version.
ifMauTypeList (Integer32 bitmask using powers of 2) was deprecated in favor of ifMauTypeListBits (SMIv2 BITS type). The BITS type is the preferred SMIv2 mechanism for encoding sets of capabilities and allows direct bit-level access without arithmetic on Integer32 sums.
The IEEE 802.3 aIdleErrorCount attribute was intentionally excluded from this MIB because it is only useful for 100BASE-T2, which is not widely implemented. Similarly, auto-negotiation selector ability objects (aAutoNegLocalSelectorAbility etc.) were excluded because they are only needed for isoethernet (802.9a) support.
Repeater ports are not represented as interfaces in the Interfaces MIB; only interface MAUs have a corresponding ifIndex. Agents implementing repeater-MAU objects must comply with RFC 2108 (802.3 Repeater MIB) but need not implement IF-MIB entries for repeater ports.
When managing a 10GBASE-W PHY, the ifMauIfIndex value equals the ifIndex of the topmost layer interface (ethernetCsmacd(6)), and the WIS layer is represented separately in ifTable/ifStackTable/ifInvStackTable per the layering model in RFC 3637.
An agent implementing interface-MAU related objects MUST also implement the relevant groups of the ifCompliance3 MODULE-COMPLIANCE statement of the Interfaces MIB. The value of ifMauIfIndex must equal the ifIndex used to instantiate the connected interface.
An agent implementing repeater-MAU related objects MUST also comply with the snmpRptrModCompl compliance statement of the 802.3 Repeater MIB (RFC 2108). The rpMauGroupIndex and rpMauPortIndex values SHALL match rptrPortGroupIndex and rptrPortIndex of the connected port.
For 10 Gb/s MAUs, when multiple reasons for a local fault state can be identified, only the highest-precedence error should be reported, in descending precedence: pxsLinkFault, pmdLinkFault, wisFrameLoss, wisSignalLoss, pcsLinkFault, excessiveBER, dxsLinkFault.
If the MAU type can be changed dynamically, the agent SHALL create ifTable, ifStackTable, and ifInvStackTable entries for the WIS when ifMauDefaultType is changed to a 10GBASE-W variant, and SHALL destroy those WIS-related entries when changed to a non-10GBASE-W type.
It is REQUIRED that an agent implementing interface-MAU related objects will also fully comply with the dot3Compliance2 MODULE-COMPLIANCE statement of the Ethernet-like Interfaces MIB (RFC 3635).
The agent MUST always return other(1) for rpMauJabberState and ifMauJabberState when the MAU type is dot3MauTypeAUI, since jabber detection does not apply to AUI MAUs.
The values remoteJabber(7), remoteLinkLoss(8), and remoteTest(9) SHOULD be used instead of remoteFault(5) for ifMauMediaAvailable where the reason for remote fault is identified in the remote signaling protocol.
When ifMauAutoNegAdminStatus transitions from enabled to disabled, the agent MUST ensure that the operational MAU type (as reported by ifMauType) correctly transitions to the value specified by ifMauDefaultType, rather than continuing to operate at the auto-negotiation-determined value.
When interface-MAU objects are used to manage a 10GBASE-W PHY (ifMauType equals dot3MauType10GigBaseW or any 10GBASE-W variant), the agent MUST also support the Ethernet WAN Interface Sublayer (WIS) MIB (RFC 3637) and follow its interface layering model.
ifMauAutoNegTable provides configuration and status for auto-negotiation on interface MAUs. Objects include admin status, remote signaling detection, config state, capability bits (local/advertised/received), restart control, and remote fault advertised/received.
ifMauDefaultType identifies the administratively-configured MAU type. When auto-negotiation is disabled, it determines the operational type; when auto-negotiation is enabled, it is the type the MAU reverts to if auto-negotiation is later disabled.
ifMauMediaAvailable enumerates link/media availability with 18 states. RFC 3636 added 10 Gb/s-specific states beyond RFC 2668: pmdLinkFault(12), wisFrameLoss(13), wisSignalLoss(14), pcsLinkFault(15), excessiveBER(16), dxsLinkFault(17), pxsLinkFault(18).
ifMauTable provides descriptive and status information about MAUs attached to interfaces. Entries are indexed by ifMauIfIndex and ifMauIndex, and include type, status, media availability, jabber, false carriers (32- and 64-bit), type list bits, default type, and auto-negotiation support flag.
JackType textual convention enumerates 14 physical connector types used by both rpJackTable and ifJackTable: other, rj45, rj45S (shielded), db9, bnc, fAUI, mAUI, fiberSC, fiberMIC, fiberST, telco, mtrj, hssdc, and fiberLC (added in RFC 3636).
rpMauTable provides descriptive and status information about MAUs attached to repeater ports. Each entry is indexed by rpMauGroupIndex, rpMauPortIndex, and rpMauIndex, and contains MAU type, status, media availability, jabber state, and false carrier counters.
The dot3MauType OID arc (mib-2.26.4) defines 40 OBJECT-IDENTITY values for standard IEEE 802.3 MAU types, from dot3MauTypeAUI(1) through dot3MauType10GigBaseSW(40). Ten 10 Gb/s entries (31–40) were added by RFC 3636.
Several objects in this MIB have read-write or read-create access: rpMauStatus, ifMauStatus, ifMauDefaultType, ifMauAutoNegAdminStatus, and ifMauAutoNegRestart. Unauthorized writes could disrupt network connectivity by changing MAU operational mode or forcing auto-negotiation restarts. Implementations should use SNMPv3 with authentication and privacy.
Auto-negotiation configuration state machine (ifMauAutoNegConfig) has five states: other(1), configuring(2), complete(3), disabled(4), parallelDetectFail(5). The parallelDetectFail state maps to a parallel detection failure per IEEE 802.3 clause 28.2.3.1.
MAU administrative state machine has six states: other(1), unknown(2), operational(3), standby(4), shutdown(5), and reset(6). Writing reset(6) triggers a power-cycle equivalent; writing standby(4) to a mixing-type MAU or AUI forces shutdown instead. Transitions are effected by writing rpMauStatus or ifMauStatus.
ifMauHCFalseCarriers is a Counter64 object (64-bit) counting false carrier events during IDLE on 100BASE-X and 1000BASE-X links. It is the high-capacity replacement for ifMauFalseCarriers (Counter32) which can roll over very quickly (minimum ~7.4 hours for 100BASE-X).
ifMauTypeListBits is a BITS object encoding MAU capability as a bit string with 41 named bits (0–40), from bOther(0) through b10GbaseSW(40), covering all standard IEEE 802.3 MAU types at 10 Mb/s, 100 Mb/s, 1000 Mb/s, and 10 Gb/s.