All MIBs › SOURCE-ROUTING-MIB
Category: Network Interfaces, Routing Protocols, VLAN and Bridging
Description:
Defines managed objects for source routing bridges used in Token Ring networks.
Imported Objects
From BRIDGE-MIB
| dot1dBridge | MODULE-IDENTITY |
| dot1dSr | OBJECT-IDENTITY |
From RFC-1212
| OBJECT-TYPE |
From RFC1155-SMI
| Counter | |
| Gauge |
What Is SOURCE-ROUTING-MIB?
SOURCE-ROUTING-MIB is a vendor-neutral IETF/IEEE standards MIB (part of the dot1d bridge MIB family, RFC 1525, built on IEEE 802.5 Token Ring source routing) defining managed objects for source-routing transparent bridges. It exposes per-port bridge configuration and topology data: hop count limits, local/target ring segment numbers, bridge number, largest frame size, and spanning tree explorer (STE) mode. Its data is primarily configuration/topology-oriented rather than hardware health telemetry, though counters for specifically-routed and all-paths-explorer frames let an operator gauge traffic load and detect misconfigured bridging loops - a form of software/protocol health monitoring. It builds directly on the IETF Bridge MIB (BRIDGE-MIB, dot1dBridge subtree) and IEEE 802.5 Token Ring standards. Typical deployment is legacy Token Ring source-route bridging/switching equipment, now largely of historical interest. Engineers can download the SOURCE-ROUTING-MIB file directly to load it into their MIB browser.
IPNetwork Monitor allows you to monitor SNMP objects defined in SOURCE-ROUTING-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.
What Can Be Monitored
- hop count per port
- local/target ring segment numbers
- bridge number
- largest frame size
- specifically-routed frame counts
- all-paths-explorer frame counts
Supported Devices
- vendor-neutral, standards-based MIB, not tied to a specific manufacturer
- Token Ring source-routing bridge/switch
Monitoring Examples
dot1dSrPortTable/Entry lists each bridge port's dot1dSrPortHopCount, dot1dSrPortLocalSegment/TargetSegment, and dot1dSrPortBridgeNum, letting an operator verify the source-route path topology is configured correctly. Polling dot1dSrPortSpecInFrames and dot1dSrPortApeInFrames reveals whether explorer frame traffic (used for route discovery) is unusually high, which could indicate a bridging loop or excessive broadcast storm across the Token Ring segment.
OIDs
| OID symbolic | OID numeric | Type | Access | Description |
|---|---|---|---|---|
| dot1dSrPortTable | 1.3.6.1.2.1.17.3.1 | not-accessible | A table that contains information about every port that is associated with this source route bridge. | |
| dot1dSrPortEntry | 1.3.6.1.2.1.17.3.1.1 | not-accessible | A list of information for each port of a source route bridge. | |
| INT dot1dSrPort | 1.3.6.1.2.1.17.3.1.1.1 | INTEGER | read-only | The port number of the port for which this entry contains Source Route management information. |
| INT dot1dSrPortHopCount | 1.3.6.1.2.1.17.3.1.1.2 | INTEGER | read-write | The maximum number of routing descriptors allowed in an All Paths or Spanning Tree Explorer frames. |
| INT dot1dSrPortLocalSegment | 1.3.6.1.2.1.17.3.1.1.3 | INTEGER | read-write | The segment number that uniquely identifies the segment to which this port is connected. Current source routing protocols limit this value to the range: 0 through 4095. (The value 0 is used by some management applications for special test cases.) A value of 65535 signifies that no segment number is assigned to this port. |
| INT dot1dSrPortBridgeNum | 1.3.6.1.2.1.17.3.1.1.4 | INTEGER | read-write | A bridge number uniquely identifies a bridge when more than one bridge is used to span the same two segments. Current source routing protocols limit this value to the range: 0 through 15. A value of 65535 signifies that no bridge number is assigned to this bridge. |
| INT dot1dSrPortTargetSegment | 1.3.6.1.2.1.17.3.1.1.5 | INTEGER | read-write | The segment number that corresponds to the target segment this port is considered to be connected to by the bridge. Current source routing protocols limit this value to the range: 0 through 4095. (The value 0 is used by some management applications for special test cases.) A value of 65535 signifies that no target segment is assigned to this port. |
| INT dot1dSrPortLargestFrame | 1.3.6.1.2.1.17.3.1.1.6 | INTEGER | read-write | The maximum size of the INFO field (LLC and above) that this port can send/receive. It does not include any MAC level (framing) octets. The value of this object is used by this bridge to determine whether a modification of the LargestFrame (LF, see [14]) field of the Routing Control field of the Routing Information Field is necessary. 64 valid values are defined by the IEEE 802.5M SRT Addendum: 516, 635, 754, 873, 993, 1112, 1231, 1350, 1470, 1542, 1615, 1688, 1761, 1833, 1906, 1979, 2052, 2345, 2638, 2932, 3225, 3518, 3812, 4105, 4399, 4865, 5331, 5798, 6264, 6730, 7197, 7663, 8130, 8539, 8949, 9358, 9768, 10178, 10587, 10997, 11407, 12199, 12992, 13785, 14578, 15370, 16163, 16956, 17749, 20730, 23711, 26693, 29674, 32655, 35637, 38618, 41600, 44591, 47583, 50575, 53567, 56559, 59551, and 65535. An illegal value will not be accepted by the bridge. |
| INT dot1dSrPortSTESpanMode | 1.3.6.1.2.1.17.3.1.1.7 | INTEGER | read-write | Determines how this port behaves when presented with a Spanning Tree Explorer frame. The value 'disabled(2)' indicates that the port will not accept or send Spanning Tree Explorer packets; any STE packets received will be silently discarded. The value 'forced(3)' indicates the port will always accept and propagate Spanning Tree Explorer frames. This allows a manually configured Spanning Tree for this class of packet to be configured. Note that unlike transparent bridging, this is not catastrophic to the network if there are loops. The value 'auto-span(1)' can only be returned by a bridge that both implements the Spanning Tree Protocol and has use of the protocol enabled on this port. The behavior of the port for Spanning Tree Explorer frames is determined by the state of dot1dStpPortState. If the port is in the 'forwarding' state, the frame will be accepted or propagated. Otherwise, it will be silently discarded. |
| CTR dot1dSrPortSpecInFrames | 1.3.6.1.2.1.17.3.1.1.8 | Counter | read-only | The number of Specifically Routed frames, also referred to as Source Routed Frames, that have been received from this port's segment. |
| CTR dot1dSrPortSpecOutFrames | 1.3.6.1.2.1.17.3.1.1.9 | Counter | read-only | The number of Specifically Routed frames, also referred to as Source Routed Frames, that this port has transmitted on its segment. |
| CTR dot1dSrPortApeInFrames | 1.3.6.1.2.1.17.3.1.1.10 | Counter | read-only | The number of All Paths Explorer frames, also referred to as All Routes Explorer frames, that have been received by this port from its segment. |
| CTR dot1dSrPortApeOutFrames | 1.3.6.1.2.1.17.3.1.1.11 | Counter | read-only | The number of all Paths Explorer Frames, also referred to as All Routes Explorer frames, that have been transmitted by this port on its segment. |
| CTR dot1dSrPortSteInFrames | 1.3.6.1.2.1.17.3.1.1.12 | Counter | read-only | The number of spanning tree explorer frames that have been received by this port from its segment. |
| CTR dot1dSrPortSteOutFrames | 1.3.6.1.2.1.17.3.1.1.13 | Counter | read-only | The number of spanning tree explorer frames that have been transmitted by this port on its segment. |
| CTR dot1dSrPortSegmentMismatchDiscards | 1.3.6.1.2.1.17.3.1.1.14 | Counter | read-only | The number of explorer frames that have been discarded by this port because the routing descriptor field contained an invalid adjacent segment value. |
| CTR dot1dSrPortDuplicateSegmentDiscards | 1.3.6.1.2.1.17.3.1.1.15 | Counter | read-only | The number of frames that have been discarded by this port because the routing descriptor field contained a duplicate segment identifier. |
| CTR dot1dSrPortHopCountExceededDiscards | 1.3.6.1.2.1.17.3.1.1.16 | Counter | read-only | The number of explorer frames that have been discarded by this port because the Routing Information Field has exceeded the maximum route descriptor length. |
| CTR dot1dSrPortDupLanIdOrTreeErrors | 1.3.6.1.2.1.17.3.1.1.17 | Counter | read-only | The number of duplicate LAN IDs or Tree errors. This helps in detection of problems in networks containing older IBM Source Routing Bridges. |
| CTR dot1dSrPortLanIdMismatches | 1.3.6.1.2.1.17.3.1.1.18 | Counter | read-only | The number of ARE and STE frames that were discarded because the last LAN ID in the routing information field did not equal the LAN-in ID. This error can occur in implementations which do only a LAN-in ID and Bridge Number check instead of a LAN-in ID, Bridge Number, and LAN-out ID check before they forward broadcast frames. |
| INT dot1dSrBridgeLfMode | 1.3.6.1.2.1.17.3.2 | INTEGER | read-write | Indicates whether the bridge operates using older 3 bit length negotiation fields or the newer 6 bit length field in its RIF. |
| dot1dPortPair | 1.3.6.1.2.1.17.10 | |||
| GAU dot1dPortPairTableSize | 1.3.6.1.2.1.17.10.1 | Gauge | read-only | The total number of entries in the Bridge Port Pair Database. |
| dot1dPortPairTable | 1.3.6.1.2.1.17.10.2 | not-accessible | A table that contains information about every port pair database entity associated with this source routing bridge. | |
| dot1dPortPairEntry | 1.3.6.1.2.1.17.10.2.1 | not-accessible | A list of information for each port pair entity of a bridge. | |
| INT dot1dPortPairLowPort | 1.3.6.1.2.1.17.10.2.1.1 | INTEGER | read-write | The port number of the lower numbered port for which this entry contains port pair database information. |
| INT dot1dPortPairHighPort | 1.3.6.1.2.1.17.10.2.1.2 | INTEGER | read-write | The port number of the higher numbered port for which this entry contains port pair database information. |
| INT dot1dPortPairBridgeNum | 1.3.6.1.2.1.17.10.2.1.3 | INTEGER | read-write | A bridge number that uniquely identifies the path provided by this source routing bridge between the segments connected to dot1dPortPairLowPort and dot1dPortPairHighPort. The purpose of bridge number is to disambiguate between multiple paths connecting the same two LANs. |
| INT dot1dPortPairBridgeState | 1.3.6.1.2.1.17.10.2.1.4 | INTEGER | read-write | The state of dot1dPortPairBridgeNum. Writing 'invalid(3)' to this object removes the corresponding entry. |
RFC description
Monitors source route bridging ports, tracking hop counts, frame statistics, and bridging parameters for SR and SRT bridges.
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