Definitions of Managed Objects for IEEE 802.3 Repeater Devices using SMIv2
obsoletes
- rfc-1516 — Definitions of Managed Objects for IEEE 802.3 Repeater Devices
Extracted elements (25)
Counters in this MIB are defined to be identical to those in IEEE Std 802.3 Section 30 so the same hardware instrumentation can implement both the IEEE and IETF management standards without duplication of effort.
Group-level monitoring counters (rptrMonitorGroupTable) are deprecated in this MIB. Management applications are recommended to use repeater-level counters in rptrMonTable, which provides the same aggregate information. Group counters were redundant summations already available via per-port objects.
rptrMonitorPortRunts is intentionally excluded from rptrMonitorPortTotalErrors because runts usually indicate collision fragments, which are a normal network event. TotalErrors sums FCSErrors, AlignmentErrors, FrameTooLongs, ShortEvents, LateEvents, VeryLongEvents, DataRateMismatches, and SymbolErrors only.
The MIB-II 'interfaces' group has NO specific relationship to repeater ports. A repeater is a physical-layer bitwise store-and-forward device with no MAC address and no MAC implementation; it does not process packets based on packet-related information such as checksum or addresses. The 'interfaces' group applies only to the network interfaces used for management traffic.
This MIB is a superset of RFC 1516, which is obsoleted and goes to historic status. All RFC 1516 objects are retained but many are deprecated. Scalar objects under rptrRptrInfo and rptrMonitorRptrInfo always duplicate the first entry of the new multi-repeater tables (rptrInfoTable and rptrMonTable) for backwards compatibility.
A port that is disabled (rptrPortAdminStatus = disabled) when power is lost or when a reset is exerted shall remain disabled when normal operation resumes. Admin status takes precedence over auto-partition and operates functionally between the auto-partition mechanism and the AUI/PMA.
A repeater implementing this MIB must also implement (at least) the 'system' group from MIB-II. The 'system' group is mandatory and applies to the managed entity even if its sole functionality is management of repeaters.
For 100Mb/s ports, rptrMonitorPortReadableOctets can roll over in less than 6 minutes, potentially shorter than a management station's poll cycle. Management stations are advised to also poll rptrMonitorPortUpper32Octets or use rptrMonitorPortHCReadableOctets (Counter64) to avoid loss of information.
If rptrMonitorPortUpper32Octets or rptrMonitorPortHCReadableOctets is implemented, the value MUST be a valid count as defined (upper 32 bits and full 64-bit count respectively). Implementation is not required in systems that do not support 100Mb/s.
When rptrInfoReset (or deprecated rptrReset) is set to reset(2), the agent may delay the reset to allow the SNMP response to be transmitted, but the SNMP response MUST be transmitted. The reset action does not reset management counters and does not affect portAdminStatus parameters.
OptMacAddr is a textual convention for an optional MAC address: either a 6-octet canonical IEEE 802.1a MAC address (OCTET STRING SIZE 6) or a zero-length string when no value is available. Unlike the SNMPv2-TC MacAddress type, a zero-length value is explicitly permitted.
rptrAddrTrackPackage (snmpDot3RptrMgt.3) provides objects for tracking MAC addresses of DTEs attached to repeater ports and for network topology mapping. This functionality is based on technology patented by Hewlett-Packard Company; HP has granted rights to this technology to MIB implementors.
rptrGroupTable (rptrBasicPackage.2.1) contains descriptive and status information for each group of ports, indexed by rptrGroupIndex. Key current fields: rptrGroupObjectID (vendor OID identifying the group hardware), rptrGroupOperStatus (operational/malfunctioning/notPresent/underTest/resetInProgress), and rptrGroupPortCapacity.
rptrInfoTable (rptrAllRptrInfo.1) is the preferred multi-repeater table replacing deprecated scalar rptrRptrInfo objects. Each entry contains rptrInfoRptrType (other/tenMb/onehundredMbClassI/onehundredMbClassII), rptrInfoOperStatus (other/ok/failure), rptrInfoReset, rptrInfoPartitionedPorts (Gauge32), and rptrInfoLastChange (TimeStamp for discontinuity detection).
rptrMonitor100PortTable provides additional 100Mb/s-specific per-port statistics: rptrMonitorPortIsolates (automatic isolations due to false carrier events per fig 27-9), rptrMonitorPortSymbolErrors (invalid data symbols in valid-length packets), rptrMonitorPortUpper32Octets (upper 32 bits of octet count), and rptrMonitorPortHCReadableOctets (Counter64 octet counter).
rptrMonitorPortDataRateMismatches counts frames received where the data rate (frequency) is detectably mismatched from the local transmit frequency, using either of two measurement methods (by activity duration or by octet count). The exact degree of detectable mismatch is vendor-specific.
rptrMonitorPortLateEvents counts CarrierEvents where activity exceeds LateEventThreshold (greater than 480 bit times and less than 565 bit times). Such an event is counted both as a collision (rptrMonitorPortCollisions) and as a lateEvent — it increments two counters simultaneously.
rptrMonitorPortTable provides per-port performance and error statistics indexed by {rptrMonitorPortGroupIndex, rptrMonitorPortIndex}: ReadableFrames, ReadableOctets, FCSErrors, AlignmentErrors, FrameTooLongs, ShortEvents, Runts, Collisions, LateEvents, VeryLongEvents, DataRateMismatches, AutoPartitions, TotalErrors, and LastChange.
rptrMonTable (rptrMonitorAllRptrInfo.1) provides per-repeater aggregate statistics indexed by rptrInfoId: rptrMonTxCollisions (TRANSMIT COLLISION/Jam state entries), rptrMonTotalFrames, rptrMonTotalErrors, and rptrMonTotalOctets. Uses rptrInfoLastChange for counter discontinuity detection.
rptrPortTable (rptrBasicPackage.3.1) contains per-port configuration and status, indexed by {rptrPortGroupIndex, rptrPortIndex}. Fields: rptrPortAdminStatus (enabled/disabled), rptrPortAutoPartitionState (notAutoPartitioned/autoPartitioned), rptrPortOperStatus (operational/notOperational/notPresent), and rptrPortRptrId (repeater membership, 0 = unassigned).
rptrTopNPackage (snmpDot3RptrMgt.4) provides objects for identifying and tracking the ports with the highest activity within the system or within particular repeaters, enabling management applications to focus on the most active network segments.
The SNMP-REPEATER-MIB module is registered as snmpDot3RptrMgt OBJECT IDENTIFIER ::= { mib-2 22 }, with module identity snmpRptrMod at { snmpDot3RptrMgt 5 }. Sub-trees include rptrBasicPackage (.1), rptrMonitorPackage (.2), rptrAddrTrackPackage (.3), and rptrTopNPackage (.4).
Section 7 addresses security considerations for the SNMP Repeater MIB. Read-write objects — particularly rptrPortAdminStatus, rptrInfoReset, and TopN control objects — can disrupt network operation if accessed by unauthorized parties. Implementors should use SNMP authentication and access control mechanisms to restrict write access to these objects.
rptrPortAdminStatus controls a port's auto-partition state machine. Setting to enabled(1) exerts a BEGIN, transitioning rptrPortAutoPartitionState to notAutoPartitioned(1) regardless of prior state. Setting to disabled(2) freezes rptrPortAutoPartitionState until the port is next enabled.
rptrPortAutoPartitionState tracks repeater auto-partition protection. For 10Mb/s (clause 9), conditions are defined in the clause 9 partition state diagram. For 100Mb/s (clause 27), a port partitions on entry to the Partition Wait state of fig 27-8; rptrMonitorPortAutoPartitions increments on each automatic partitioning.