Definitions of Managed Objects for IEEE 802.3 Medium Attachment Units (MAUs)
obsoletes
- rfc-3636 — Definitions of Managed Objects for IEEE 802.3 Medium Attachment Units (MAUs)
Extracted elements (25)
Integer-based capability objects (ifMauTypeList, ifMauAutoNegCapability, ifMauAutoNegCapAdvertised, ifMauAutoNegCapReceived) and the JackType TC are deprecated in favor of BITS-based textual conventions (IANAifMauTypeListBits, IANAifMauAutoNegCapBits, IANAifJackType) defined in IANA-MAU-MIB. Bit-string TCs allow IANA to add new capability bits without reissuing this document.
Moving MAU type OBJECT-IDENTITY definitions from MAU-MIB to IANA-MAU-MIB is not strictly compliant with SMIv2 rules governing MIB module revisions (RFC 2578, Section 10), but the deviation is explicitly justified because continued high maintenance costs would result from not making the change. The working group found no existing MIB modules or management applications that would actually be negatively affected.
RFC 4836 splits RFC 3636's single MIB module into two: a stable MAU-MIB and a new IANA-maintained IANA-MAU-MIB. This separation means that when new MAU types, Media Available states, Auto-Negotiation capabilities, or Jack types are defined by IEEE 802.3, only the IANA-maintained module needs updating, leaving the base MAU-MIB module unchanged and reducing the frequency of standards-track updates.
The broadMauBasicTable for 10BROAD36 broadband MAUs is deprecated in this revision. There have been no reported implementations of this table, and it is unlikely there ever will be; IEEE recommends that broadband MAU types should not be used for new installations.
Three IEEE 802.3 managed objects were intentionally excluded from the MAU-MIB: aIdleErrorCount (only useful for 100BaseT2, which is not widely implemented) and the auto-negotiation selector ability attributes (aAutoNegLocalSelectorAbility, aAutoNegAdvertisedSelectorAbility, aAutoNegReceivedSelectorAbility), which are only needed for isoethernet (802.9a) support not covered by this MIB.
MIB modules that currently import MAU type OBJECT-IDENTITY descriptors from MAU-MIB will need to be revised to import those descriptors from IANA-MAU-MIB. Management applications that process OBJECT-IDENTITY definitions to present DESCRIPTION text to users will similarly need to obtain those definitions from IANA-MAU-MIB instead of MAU-MIB.
An agent implementing interface-MAU related objects MUST also implement the relevant groups of the ifCompliance3 MODULE-COMPLIANCE statement of the Interface MIB (RFC 2863); the value of ifMauIfIndex must equal the corresponding ifIndex.
An agent implementing repeater-MAU related objects MUST also comply with the snmpRptrModCompl compliance statement of the 802.3 Repeater MIB (RFC 2108); the values of rpMauGroupIndex and rpMauPortIndex SHALL be the same as rptrPortGroupIndex and rptrPortIndex for the connected port.
An agent implementing the interface-MAU related objects in MAU-MIB is REQUIRED to fully comply with the dot3Compliance2 MODULE-COMPLIANCE statement of the Ethernet-like Interfaces MIB (RFC 3635).
An Expert Review, as defined in RFC 2434, is REQUIRED for addition of new MAU types, Media Available states, Auto-Negotiation capabilities, and/or Jack types to the IANA-maintained IANA-MAU-MIB. When new MAU types require additional managed objects or have side effects on existing objects, a standards-track specification is also REQUIRED.
The agent MUST always return other(1) for rpMauJabberState and ifMauJabberState when the MAU type is dot3MauTypeAUI.
The agent MUST throttle the generation of consecutive rpMauJabberTraps (and ifMauJabberTraps) so that there is at least a five-second gap between them when a MAU is in or re-enters the jabber state.
When ifMauAutoNegAdminStatus transitions from enabled to disabled, the agent MUST ensure that the operational type of the MAU (ifMauType) correctly transitions to the value specified by ifMauDefaultType, rather than continuing at the value determined by the auto-negotiation function.
When ifMauDefaultType is changed to a 10GBASE-W variant, the agent SHALL create ifTable, ifStackTable, and ifInvStackTable entries pertaining to the WIS; when changed to a non-10GBASE-W type, the agent shall destroy those WIS-related entries and update ifConnectorPresent and ifHighSpeed accordingly, but SHALL NOT otherwise alter the ifTable entry.
When interface-MAU objects are used to manage a 10GBASE-W PHY (ifMauType equal to 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.
ifMauDefaultType is a read-write AutonomousType object identifying 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 will revert to if auto-negotiation is later disabled. Implementors must ensure ifMauType tracks this value correctly when auto-negotiation is disabled.
ifMauHCFalseCarriers is a 64-bit Counter64 counting false carrier events during IDLE in 100BASE-X and 1000BASE-X links. It is provided because the 32-bit ifMauFalseCarriers counter (which can increment at up to once per 10 µs for 1000BASE-X) rolls over very quickly; management stations are advised to poll the 64-bit version to avoid loss of information.
The ifMauAutoNegTable provides auto-negotiation configuration and status indexed by {ifMauIfIndex, ifMauIndex}. Key objects include ifMauAutoNegAdminStatus (enabled/disabled, read-write), ifMauAutoNegRemoteSignaling (detected/notdetected), ifMauAutoNegCapabilityBits (local caps), ifMauAutoNegCapAdvertisedBits (advertised caps, read-write), ifMauAutoNegCapReceivedBits (remote caps), ifMauAutoNegRestart, and remote fault advertised/received objects for 1000 Mbps MAUs.
The ifMauTable is the basic interface MAU table, indexed by {ifMauIfIndex, ifMauIndex}. Each entry carries ifMauType (operational MAU type), ifMauStatus, ifMauMediaAvailable, ifMauMediaAvailableStateExits, ifMauJabberState, ifMauJabberingStateEnters, ifMauFalseCarriers (Counter32), ifMauDefaultType (read-write administrative type), ifMauAutoNegSupported (TruthValue), ifMauTypeListBits (IANAifMauTypeListBits), and ifMauHCFalseCarriers (Counter64).
The rpJackTable and ifJackTable provide information about external jack connectors attached to MAUs on repeater ports and interfaces respectively. Each entry carries a jack index and an IANAifJackType value identifying the connector type as it appears on the outside of the system.
The rpMauTable is the basic repeater MAU table, indexed by {rpMauGroupIndex, rpMauPortIndex, rpMauIndex}. Each entry carries rpMauType (OID identifying the MAU type), rpMauStatus (admin/operational state), rpMauMediaAvailable, rpMauMediaAvailableStateExits (Counter32), rpMauJabberState, rpMauJabberingStateEnters (Counter32), and rpMauFalseCarriers (Counter32).
This document defines the first version of IANA-MAU-MIB, an IANA-maintained MIB module containing: dot3MauType OBJECT-IDENTITY definitions for all standard IEEE 802.3 MAU types (including EFM and 10GBASE-CX4 additions), IANAifMauTypeListBits TC (capability bitmap), IANAifMauMediaAvailable TC (media availability enumeration), IANAifMauAutoNegCapBits TC (auto-negotiation capability bitmap), and IANAifJackType TC (connector types). New entries require Expert Review.
Several read-write objects in the MAU-MIB—including ifMauStatus, rpMauStatus, ifMauDefaultType, ifMauAutoNegAdminStatus, ifMauAutoNegCapAdvertisedBits, and ifMauAutoNegRestart—can be used to disrupt or reconfigure network interfaces if accessed by unauthorized parties. Implementations should apply SNMP authentication and privacy (e.g., SNMPv3 USM) to control access to these sensitive writable objects.
The ifMauAutoNegConfig object reports auto-negotiation process status with states: other(1), configuring(2), complete(3), disabled(4), and parallelDetectFail(5). The parallelDetectFail state maps to a failure in parallel detection as defined in IEEE 802.3 clause 28.2.3.1.
The MAU administrative/operational status (rpMauStatus/ifMauStatus) has six states: other(1), unknown(2), operational(3), standby(4), shutdown(5), and reset(6). Writing operational, standby, or shutdown transitions the MAU to that state; writing standby to a mixing-type MAU or AUI causes it to enter shutdown instead. Writing reset triggers a power-cycle equivalent of at least half a second.