IF-MIB

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Organization: IETF Interfaces MIB Working Group

Last Updated: 2000-06-14

Category: Network Interfaces

Description: Defines managed objects for managing network interfaces, including interface status, error counters, and packet send/receive statistics for every interface on a network node.

IPNetwork Monitor uses several OIDs from this MIB in network discovery and polling the applicable devices. Start monitoring IF-MIB with a free 30-day trial of IPNetwork Monitor.

What Is IF-MIB?

IF-MIB is the foundational, vendor-neutral IETF standards MIB (RFC 2863) defining generic managed objects for network interface sub-layers, superseding the original MIB-II ifTable and used on virtually every SNMP-capable device. It exposes per-interface data including type, MTU, speed, physical address, administrative and operational status, and traffic/error counters for every interface on a node. It is one of the most heavily relied-upon MIBs for monitoring interface hardware/software status: ifOperStatus versus ifAdminStatus reveals whether a link is up or down, while counters expose traffic load, discards, and errors hinting at cabling, driver, or congestion problems. It underlies and is referenced by nearly every other interface-related MIB, such as EtherLike-MIB and IEEE8023-LAG-MIB, through the shared ifIndex. It is deployed universally across routers, switches, servers, and any managed network node that exposes interface status via SNMP, and if-mib is typically the very first MIB an administrator loads when setting up interface-level monitoring.

IPNetwork Monitor allows you to monitor SNMP objects defined in IF-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.

Supported Devices

vendor-neutral, standards-based MIB, not tied to a specific manufacturer
any SNMP-managed network device with interfaces (routers, switches, servers, hosts)

Monitoring Examples

Polling ifTable/ifEntry by ifIndex, an admin compares ifOperStatus against ifAdminStatus for a given ifDescr to detect an interface that is administratively up but operationally down, signaling a cable or link fault. ifSpeed together with ifType (e.g., ethernetCsmacd) contextualizes whether observed throughput is nearing capacity, and a change in ifNumber or a recent ifTableLastChange indicates an interface was added, removed, or renumbered.

What Can Be Monitored

interface admin/operational status
interface speed and MTU
interface type and physical address
total interface count
interface table change timestamp
interface description/index mapping

Imported Objects

From IANAifType-MIB

IANAifType

From SNMPv2-CONF

MODULE-COMPLIANCE
NOTIFICATION-GROUP
OBJECT-GROUP

From SNMPv2-MIB

snmpTraps

OBJECT-IDENTITY

From SNMPv2-SMI

Counter32
Counter64
Gauge32
Integer32
MODULE-IDENTITY
NOTIFICATION-TYPE
OBJECT-TYPE
TimeTicks
mib-2

From SNMPv2-TC

AutonomousType
DisplayString
PhysAddress
RowStatus
TEXTUAL-CONVENTION
TestAndIncr
TimeStamp
TruthValue

How to Use in IPNetwork Monitor

Example using ifNumber OID:

Select a device implementing IF-MIB as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and type ifNumber into the Find box to locate it in the OID tree, then select it and click OK. It reports the total number of network interfaces present on the device, regardless of their current operational state. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is an Integer32-type OID, Value bounds is the most useful condition here — trigger an alert if the interface count changes unexpectedly, which can indicate a module was added, removed, or failed to initialize. Click Finish to create the monitor; you can adjust any parameter later.

OIDs

OID symbolic	OID numeric	Type	Access	Description
INT ifAdminStatus	1.3.6.1.2.1.2.2.1.7	INTEGER	read-write	The desired state of the interface. The testing(3) state indicates that no operational packets can be passed. When a managed system initializes, all interfaces start with ifAdminStatus in the down(2) state. As a result of either explicit management action or per configuration information retained by the managed system, ifAdminStatus is then changed to either the up(1) or testing(3) states (or remains in the down(2) state).
STR ifAlias	1.3.6.1.2.1.31.1.1.1.18	DisplayString	read-write	This object is an 'alias' name for the interface as specified by a network manager, and provides a non-volatile 'handle' for the interface. On the first instantiation of an interface, the value of ifAlias associated with that interface is the zero-length string. As and when a value is written into an instance of ifAlias through a network management set operation, then the agent must retain the supplied value in the ifAlias instance associated with the same interface for as long as that interface remains instantiated, including across all re- initializations/reboots of the network management system, including those which result in a change of the interface's ifIndex value. An example of the value which a network manager might store in this object for a WAN interface is the (Telco's) circuit number/identifier of the interface. Some agents may support write-access only for interfaces having particular values of ifType. An agent which supports write access to this object is required to keep the value in non-volatile storage, but it may limit the length of new values depending on how much storage is already occupied by the current values for other interfaces.
ifCompliance	1.3.6.1.2.1.31.2.2.1			A compliance statement defined in a previous version of this MIB module, for SNMP entities which have network interfaces.
ifCompliance2	1.3.6.1.2.1.31.2.2.2			A compliance statement defined in a previous version of this MIB module, for SNMP entities which have network interfaces.
ifCompliance3	1.3.6.1.2.1.31.2.2.3			The compliance statement for SNMP entities which have network interfaces.
ifCompliances	1.3.6.1.2.1.31.2.2
ifConformance	1.3.6.1.2.1.31.2
T/F ifConnectorPresent	1.3.6.1.2.1.31.1.1.1.17	TruthValue	read-only	This object has the value 'true(1)' if the interface sublayer has a physical connector and the value 'false(2)' otherwise.
ifCounterDiscontinuityGroup	1.3.6.1.2.1.31.2.1.13			A collection of objects providing information specific to interface counter discontinuities.
TIM ifCounterDiscontinuityTime	1.3.6.1.2.1.31.1.1.1.19	TimeStamp	read-only	The value of sysUpTime on the most recent occasion at which any one or more of this interface's counters suffered a discontinuity. The relevant counters are the specific instances associated with this interface of any Counter32 or Counter64 object contained in the ifTable or ifXTable. If no such discontinuities have occurred since the last re- initialization of the local management subsystem, then this object contains a zero value.
STR ifDescr	1.3.6.1.2.1.2.2.1.2	DisplayString	read-only	A textual string containing information about the interface. This string should include the name of the manufacturer, the product name and the version of the interface hardware/software.
ifEntry	1.3.6.1.2.1.2.2.1		not-accessible	An entry containing management information applicable to a particular interface.
ifFixedLengthGroup	1.3.6.1.2.1.31.2.1.2			A collection of objects providing information specific to non-high speed (non-high speed interfaces transmit and receive at speeds less than or equal to 20,000,000 bits/second) character-oriented or fixed-length-transmission network interfaces.
ifGeneralGroup	1.3.6.1.2.1.31.2.1.1			A collection of objects deprecated in favour of ifGeneralInformationGroup.
ifGeneralInformationGroup	1.3.6.1.2.1.31.2.1.10			A collection of objects providing information applicable to all network interfaces.
ifGroups	1.3.6.1.2.1.31.2.1
ifHCFixedLengthGroup	1.3.6.1.2.1.31.2.1.3			A collection of objects providing information specific to high speed (greater than 20,000,000 bits/second) character- oriented or fixed-length-transmission network interfaces.
C64 ifHCInBroadcastPkts	1.3.6.1.2.1.31.1.1.1.9	Counter64	read-only	The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were addressed to a broadcast address at this sub-layer. This object is a 64-bit version of ifInBroadcastPkts. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C64 ifHCInMulticastPkts	1.3.6.1.2.1.31.1.1.1.8	Counter64	read-only	The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were addressed to a multicast address at this sub-layer. For a MAC layer protocol, this includes both Group and Functional addresses. This object is a 64-bit version of ifInMulticastPkts. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C64 ifHCInOctets	1.3.6.1.2.1.31.1.1.1.6	Counter64	read-only	The total number of octets received on the interface, including framing characters. This object is a 64-bit version of ifInOctets. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C64 ifHCInUcastPkts	1.3.6.1.2.1.31.1.1.1.7	Counter64	read-only	The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were not addressed to a multicast or broadcast address at this sub-layer. This object is a 64-bit version of ifInUcastPkts. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C64 ifHCOutBroadcastPkts	1.3.6.1.2.1.31.1.1.1.13	Counter64	read-only	The total number of packets that higher-level protocols requested be transmitted, and which were addressed to a broadcast address at this sub-layer, including those that were discarded or not sent. This object is a 64-bit version of ifOutBroadcastPkts. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C64 ifHCOutMulticastPkts	1.3.6.1.2.1.31.1.1.1.12	Counter64	read-only	The total number of packets that higher-level protocols requested be transmitted, and which were addressed to a multicast address at this sub-layer, including those that were discarded or not sent. For a MAC layer protocol, this includes both Group and Functional addresses. This object is a 64-bit version of ifOutMulticastPkts. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C64 ifHCOutOctets	1.3.6.1.2.1.31.1.1.1.10	Counter64	read-only	The total number of octets transmitted out of the interface, including framing characters. This object is a 64-bit version of ifOutOctets. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C64 ifHCOutUcastPkts	1.3.6.1.2.1.31.1.1.1.11	Counter64	read-only	The total number of packets that higher-level protocols requested be transmitted, and which were not addressed to a multicast or broadcast address at this sub-layer, including those that were discarded or not sent. This object is a 64-bit version of ifOutUcastPkts. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
ifHCPacketGroup	1.3.6.1.2.1.31.2.1.5			A collection of objects providing information specific to high speed (greater than 20,000,000 bits/second but less than or equal to 650,000,000 bits/second) packet-oriented network interfaces.
G32 ifHighSpeed	1.3.6.1.2.1.31.1.1.1.15	Gauge32	read-only	An estimate of the interface's current bandwidth in units of 1,000,000 bits per second. If this object reports a value of `n' then the speed of the interface is somewhere in the range of `n-500,000' to `n+499,999'. For interfaces which do not vary in bandwidth or for those where no accurate estimation can be made, this object should contain the nominal bandwidth. For a sub-layer which has no concept of bandwidth, this object should be zero.
C32 ifInBroadcastPkts	1.3.6.1.2.1.31.1.1.1.3	Counter32	read-only	The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were addressed to a broadcast address at this sub-layer. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
NUM ifIndex	1.3.6.1.2.1.2.2.1.1	InterfaceIndex	read-only	A unique value, greater than zero, for each interface. It is recommended that values are assigned contiguously starting from 1. The value for each interface sub-layer must remain constant at least from one re-initialization of the entity's network management system to the next re- initialization.
C32 ifInDiscards	1.3.6.1.2.1.2.2.1.13	Counter32	read-only	The number of inbound packets which were chosen to be discarded even though no errors had been detected to prevent their being deliverable to a higher-layer protocol. One possible reason for discarding such a packet could be to free up buffer space. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifInErrors	1.3.6.1.2.1.2.2.1.14	Counter32	read-only	For packet-oriented interfaces, the number of inbound packets that contained errors preventing them from being deliverable to a higher-layer protocol. For character- oriented or fixed-length interfaces, the number of inbound transmission units that contained errors preventing them from being deliverable to a higher-layer protocol. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifInMulticastPkts	1.3.6.1.2.1.31.1.1.1.2	Counter32	read-only	The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were addressed to a multicast address at this sub-layer. For a MAC layer protocol, this includes both Group and Functional addresses. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifInNUcastPkts	1.3.6.1.2.1.2.2.1.12	Counter32	read-only	The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were addressed to a multicast or broadcast address at this sub-layer. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime. This object is deprecated in favour of ifInMulticastPkts and ifInBroadcastPkts.
C32 ifInOctets	1.3.6.1.2.1.2.2.1.10	Counter32	read-only	The total number of octets received on the interface, including framing characters. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifInUcastPkts	1.3.6.1.2.1.2.2.1.11	Counter32	read-only	The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were not addressed to a multicast or broadcast address at this sub-layer. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifInUnknownProtos	1.3.6.1.2.1.2.2.1.15	Counter32	read-only	For packet-oriented interfaces, the number of packets received via the interface which were discarded because of an unknown or unsupported protocol. For character-oriented or fixed-length interfaces that support protocol multiplexing the number of transmission units received via the interface which were discarded because of an unknown or unsupported protocol. For any interface that does not support protocol multiplexing, this counter will always be 0. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
TIK ifLastChange	1.3.6.1.2.1.2.2.1.9	TimeTicks	read-only	The value of sysUpTime at the time the interface entered its current operational state. If the current state was entered prior to the last re-initialization of the local network management subsystem, then this object contains a zero value.
INT ifLinkUpDownTrapEnable	1.3.6.1.2.1.31.1.1.1.14	INTEGER	read-write	Indicates whether linkUp/linkDown traps should be generated for this interface. By default, this object should have the value enabled(1) for interfaces which do not operate on 'top' of any other interface (as defined in the ifStackTable), and disabled(2) otherwise.
ifMIB	1.3.6.1.2.1.31			The MIB module to describe generic objects for network interface sub-layers. This MIB is an updated version of MIB-II's ifTable, and incorporates the extensions defined in RFC 1229.
ifMIBObjects	1.3.6.1.2.1.31.1
I32 ifMtu	1.3.6.1.2.1.2.2.1.4	Integer32	read-only	The size of the largest packet which can be sent/received on the interface, specified in octets. For interfaces that are used for transmitting network datagrams, this is the size of the largest network datagram that can be sent on the interface.
STR ifName	1.3.6.1.2.1.31.1.1.1.1	DisplayString	read-only	The textual name of the interface. The value of this object should be the name of the interface as assigned by the local device and should be suitable for use in commands entered at the device's `console'. This might be a text name, such as `le0' or a simple port number, such as `1', depending on the interface naming syntax of the device. If several entries in the ifTable together represent a single interface as named by the device, then each will have the same value of ifName. Note that for an agent which responds to SNMP queries concerning an interface on some other (proxied) device, then the value of ifName for such an interface is the proxied device's local name for it. If there is no local name, or this object is otherwise not applicable, then this object contains a zero-length string.
I32 ifNumberEx	1.3.6.1.2.1.2.1	Integer32	read-only	The number of network interfaces (regardless of their current state) present on this system.
ifOldObjectsGroup	1.3.6.1.2.1.31.2.1.12			The collection of objects deprecated from the original MIB- II interfaces group.
INT ifOperStatus	1.3.6.1.2.1.2.2.1.8	INTEGER	read-only	The current operational state of the interface. The testing(3) state indicates that no operational packets can be passed. If ifAdminStatus is down(2) then ifOperStatus should be down(2). If ifAdminStatus is changed to up(1) then ifOperStatus should change to up(1) if the interface is ready to transmit and receive network traffic; it should change to dormant(5) if the interface is waiting for external actions (such as a serial line waiting for an incoming connection); it should remain in the down(2) state if and only if there is a fault that prevents it from going to the up(1) state; it should remain in the notPresent(6) state if the interface has missing (typically, hardware) components.
C32 ifOutBroadcastPkts	1.3.6.1.2.1.31.1.1.1.5	Counter32	read-only	The total number of packets that higher-level protocols requested be transmitted, and which were addressed to a broadcast address at this sub-layer, including those that were discarded or not sent. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifOutDiscards	1.3.6.1.2.1.2.2.1.19	Counter32	read-only	The number of outbound packets which were chosen to be discarded even though no errors had been detected to prevent their being transmitted. One possible reason for discarding such a packet could be to free up buffer space. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifOutErrors	1.3.6.1.2.1.2.2.1.20	Counter32	read-only	For packet-oriented interfaces, the number of outbound packets that could not be transmitted because of errors. For character-oriented or fixed-length interfaces, the number of outbound transmission units that could not be transmitted because of errors. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifOutMulticastPkts	1.3.6.1.2.1.31.1.1.1.4	Counter32	read-only	The total number of packets that higher-level protocols requested be transmitted, and which were addressed to a multicast address at this sub-layer, including those that were discarded or not sent. For a MAC layer protocol, this includes both Group and Functional addresses. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
C32 ifOutNUcastPkts	1.3.6.1.2.1.2.2.1.18	Counter32	read-only	The total number of packets that higher-level protocols requested be transmitted, and which were addressed to a multicast or broadcast address at this sub-layer, including those that were discarded or not sent. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime. This object is deprecated in favour of ifOutMulticastPkts and ifOutBroadcastPkts.
C32 ifOutOctets	1.3.6.1.2.1.2.2.1.16	Counter32	read-only	The total number of octets transmitted out of the interface, including framing characters. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
G32 ifOutQLen	1.3.6.1.2.1.2.2.1.21	Gauge32	read-only	The length of the output packet queue (in packets).
C32 ifOutUcastPkts	1.3.6.1.2.1.2.2.1.17	Counter32	read-only	The total number of packets that higher-level protocols requested be transmitted, and which were not addressed to a multicast or broadcast address at this sub-layer, including those that were discarded or not sent. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
ifPacketGroup	1.3.6.1.2.1.31.2.1.4			A collection of objects providing information specific to non-high speed (non-high speed interfaces transmit and receive at speeds less than or equal to 20,000,000 bits/second) packet-oriented network interfaces.
PHY ifPhysAddress	1.3.6.1.2.1.2.2.1.6	PhysAddress	read-only	The interface's address at its protocol sub-layer. For example, for an 802.x interface, this object normally contains a MAC address. The interface's media-specific MIB must define the bit and byte ordering and the format of the value of this object. For interfaces which do not have such an address (e.g., a serial line), this object should contain an octet string of zero length.
T/F ifPromiscuousMode	1.3.6.1.2.1.31.1.1.1.16	TruthValue	read-write	This object has a value of false(2) if this interface only accepts packets/frames that are addressed to this station. This object has a value of true(1) when the station accepts all packets/frames transmitted on the media. The value true(1) is only legal on certain types of media. If legal, setting this object to a value of true(1) may require the interface to be reset before becoming effective. The value of ifPromiscuousMode does not affect the reception of broadcast and multicast packets/frames by the interface.
PHY ifRcvAddressAddress	1.3.6.1.2.1.31.1.4.1.1	PhysAddress	not-accessible	An address for which the system will accept packets/frames on this entry's interface.
ifRcvAddressEntry	1.3.6.1.2.1.31.1.4.1		not-accessible	A list of objects identifying an address for which the system will accept packets/frames on the particular interface identified by the index value ifIndex.
ifRcvAddressGroup	1.3.6.1.2.1.31.2.1.7			A collection of objects providing information on the multiple addresses which an interface receives.
ROW ifRcvAddressStatus	1.3.6.1.2.1.31.1.4.1.2	RowStatus	read-create	This object is used to create and delete rows in the ifRcvAddressTable.
ifRcvAddressTable	1.3.6.1.2.1.31.1.4		not-accessible	This table contains an entry for each address (broadcast, multicast, or uni-cast) for which the system will receive packets/frames on a particular interface, except as follows: - for an interface operating in promiscuous mode, entries are only required for those addresses for which the system would receive frames were it not operating in promiscuous mode. - for 802.5 functional addresses, only one entry is required, for the address which has the functional address bit ANDed with the bit mask of all functional addresses for which the interface will accept frames. A system is normally able to use any unicast address which corresponds to an entry in this table as a source address.
INT ifRcvAddressType	1.3.6.1.2.1.31.1.4.1.3	INTEGER	read-create	This object has the value nonVolatile(3) for those entries in the table which are valid and will not be deleted by the next restart of the managed system. Entries having the value volatile(2) are valid and exist, but have not been saved, so that will not exist after the next restart of the managed system. Entries having the value other(1) are valid and exist but are not classified as to whether they will continue to exist after the next restart.
OID ifSpecific	1.3.6.1.2.1.2.2.1.22	OBJECT IDENTIFIER	read-only	A reference to MIB definitions specific to the particular media being used to realize the interface. It is recommended that this value point to an instance of a MIB object in the media-specific MIB, i.e., that this object have the semantics associated with the InstancePointer textual convention defined in RFC 2579. In fact, it is recommended that the media-specific MIB specify what value ifSpecific should/can take for values of ifType. If no MIB definitions specific to the particular media are available, the value should be set to the OBJECT IDENTIFIER { 0 0 }.
G32 ifSpeed	1.3.6.1.2.1.2.2.1.5	Gauge32	read-only	An estimate of the interface's current bandwidth in bits per second. For interfaces which do not vary in bandwidth or for those where no accurate estimation can be made, this object should contain the nominal bandwidth. If the bandwidth of the interface is greater than the maximum value reportable by this object then this object should report its maximum value (4,294,967,295) and ifHighSpeed must be used to report the interace's speed. For a sub-layer which has no concept of bandwidth, this object should be zero.
ifStackEntry	1.3.6.1.2.1.31.1.2.1		not-accessible	Information on a particular relationship between two sub- layers, specifying that one sub-layer runs on 'top' of the other sub-layer. Each sub-layer corresponds to a conceptual row in the ifTable.
ifStackGroup	1.3.6.1.2.1.31.2.1.9			The previous collection of objects providing information on the layering of MIB-II interfaces.
ifStackGroup2	1.3.6.1.2.1.31.2.1.11			A collection of objects providing information on the layering of MIB-II interfaces.
NUM ifStackHigherLayer	1.3.6.1.2.1.31.1.2.1.1	InterfaceIndexOrZero	not-accessible	The value of ifIndex corresponding to the higher sub-layer of the relationship, i.e., the sub-layer which runs on 'top' of the sub-layer identified by the corresponding instance of ifStackLowerLayer. If there is no higher sub-layer (below the internetwork layer), then this object has the value 0.
TIK ifStackLastChange	1.3.6.1.2.1.31.1.6	TimeTicks	read-only	The value of sysUpTime at the time of the last change of the (whole) interface stack. A change of the interface stack is defined to be any creation, deletion, or change in value of any instance of ifStackStatus. If the interface stack has been unchanged since the last re-initialization of the local network management subsystem, then this object contains a zero value.
NUM ifStackLowerLayer	1.3.6.1.2.1.31.1.2.1.2	InterfaceIndexOrZero	not-accessible	The value of ifIndex corresponding to the lower sub-layer of the relationship, i.e., the sub-layer which runs 'below' the sub-layer identified by the corresponding instance of ifStackHigherLayer. If there is no lower sub-layer, then this object has the value 0.
ROW ifStackStatus	1.3.6.1.2.1.31.1.2.1.3	RowStatus	read-create	The status of the relationship between two sub-layers. Changing the value of this object from 'active' to 'notInService' or 'destroy' will likely have consequences up and down the interface stack. Thus, write access to this object is likely to be inappropriate for some types of interfaces, and many implementations will choose not to support write-access for any type of interface.
ifStackTable	1.3.6.1.2.1.31.1.2		not-accessible	The table containing information on the relationships between the multiple sub-layers of network interfaces. In particular, it contains information on which sub-layers run 'on top of' which other sub-layers, where each sub-layer corresponds to a conceptual row in the ifTable. For example, when the sub-layer with ifIndex value x runs over the sub-layer with ifIndex value y, then this table contains: ifStackStatus.x.y=active For each ifIndex value, I, which identifies an active interface, there are always at least two instantiated rows in this table associated with I. For one of these rows, I is the value of ifStackHigherLayer; for the other, I is the value of ifStackLowerLayer. (If I is not involved in multiplexing, then these are the only two rows associated with I.) For example, two rows exist even for an interface which has no others stacked on top or below it: ifStackStatus.0.x=active ifStackStatus.x.0=active
ifTable	1.3.6.1.2.1.2.2		not-accessible	A list of interface entries. The number of entries is given by the value of ifNumber.
TIK ifTableLastChange	1.3.6.1.2.1.31.1.5	TimeTicks	read-only	The value of sysUpTime at the time of the last creation or deletion of an entry in the ifTable. If the number of entries has been unchanged since the last re-initialization of the local network management subsystem, then this object contains a zero value.
OID ifTestCode	1.3.6.1.2.1.31.1.3.1.5	OBJECT IDENTIFIER	read-only	This object contains a code which contains more specific information on the test result, for example an error-code after a failed test. Error codes and other values this object may take are specific to the type of interface and/or test. The value may have the semantics of either the AutonomousType or InstancePointer textual conventions as defined in RFC 2579. The identifier: testCodeUnknown OBJECT IDENTIFIER ::= { 0 0 } is defined for use if no additional result code is available.
ifTestEntry	1.3.6.1.2.1.31.1.3.1		not-accessible	An entry containing objects for invoking tests on an interface.
ifTestGroup	1.3.6.1.2.1.31.2.1.8			A collection of objects providing the ability to invoke tests on an interface.
TES ifTestId	1.3.6.1.2.1.31.1.3.1.1	TestAndIncr	read-write	This object identifies the current invocation of the interface's test.
STR ifTestOwner	1.3.6.1.2.1.31.1.3.1.6	OwnerString	read-write	The entity which currently has the 'ownership' required to invoke a test on this interface.
INT ifTestResult	1.3.6.1.2.1.31.1.3.1.4	INTEGER	read-only	This object contains the result of the most recently requested test, or the value none(1) if no tests have been requested since the last reset. Note that this facility provides no provision for saving the results of one test when starting another, as could be required if used by multiple managers concurrently.
INT ifTestStatus	1.3.6.1.2.1.31.1.3.1.2	INTEGER	read-write	This object indicates whether or not some manager currently has the necessary 'ownership' required to invoke a test on this interface. A write to this object is only successful when it changes its value from 'notInUse(1)' to 'inUse(2)'. After completion of a test, the agent resets the value back to 'notInUse(1)'.
ifTestTable	1.3.6.1.2.1.31.1.3		not-accessible	This table contains one entry per interface. It defines objects which allow a network manager to instruct an agent to test an interface for various faults. Tests for an interface are defined in the media-specific MIB for that interface. After invoking a test, the object ifTestResult can be read to determine the outcome. If an agent can not perform the test, ifTestResult is set to so indicate. The object ifTestCode can be used to provide further test- specific or interface-specific (or even enterprise-specific) information concerning the outcome of the test. Only one test can be in progress on each interface at any one time. If one test is in progress when another test is invoked, the second test is rejected. Some agents may reject a test when a prior test is active on another interface. Before starting a test, a manager-station must first obtain 'ownership' of the entry in the ifTestTable for the interface to be tested. This is accomplished with the ifTestId and ifTestStatus objects as follows: try_again: get (ifTestId, ifTestStatus) while (ifTestStatus != notInUse) /* * Loop while a test is running or some other * manager is configuring a test. / short delay get (ifTestId, ifTestStatus) } / * Is not being used right now -- let's compete * to see who gets it. / lock_value = ifTestId if ( set(ifTestId = lock_value, ifTestStatus = inUse, ifTestOwner = 'my-IP-address') == FAILURE) / * Another manager got the ifTestEntry -- go * try again / goto try_again; / * I have the lock / set up any test parameters. / * This starts the test */ set(ifTestType = test_to_run); wait for test completion by polling ifTestResult when test completes, agent sets ifTestResult agent also sets ifTestStatus = 'notInUse' retrieve any additional test results, and ifTestId if (ifTestId == lock_value+1) results are valid A manager station first retrieves the value of the appropriate ifTestId and ifTestStatus objects, periodically repeating the retrieval if necessary, until the value of ifTestStatus is 'notInUse'. The manager station then tries to set the same ifTestId object to the value it just retrieved, the same ifTestStatus object to 'inUse', and the corresponding ifTestOwner object to a value indicating itself. If the set operation succeeds then the manager has obtained ownership of the ifTestEntry, and the value of the ifTestId object is incremented by the agent (per the semantics of TestAndIncr). Failure of the set operation indicates that some other manager has obtained ownership of the ifTestEntry. Once ownership is obtained, any test parameters can be setup, and then the test is initiated by setting ifTestType. On completion of the test, the agent sets ifTestStatus to 'notInUse'. Once this occurs, the manager can retrieve the results. In the (rare) event that the invocation of tests by two network managers were to overlap, then there would be a possibility that the first test's results might be overwritten by the second test's results prior to the first results being read. This unlikely circumstance can be detected by a network manager retrieving ifTestId at the same time as retrieving the test results, and ensuring that the results are for the desired request. If ifTestType is not set within an abnormally long period of time after ownership is obtained, the agent should time-out the manager, and reset the value of the ifTestStatus object back to 'notInUse'. It is suggested that this time-out period be 5 minutes. In general, a management station must not retransmit a request to invoke a test for which it does not receive a response; instead, it properly inspects an agent's MIB to determine if the invocation was successful. Only if the invocation was unsuccessful, is the invocation request retransmitted. Some tests may require the interface to be taken off-line in order to execute them, or may even require the agent to reboot after completion of the test. In these circumstances, communication with the management station invoking the test may be lost until after completion of the test. An agent is not required to support such tests. However, if such tests are supported, then the agent should make every effort to transmit a response to the request which invoked the test prior to losing communication. When the agent is restored to normal service, the results of the test are properly made available in the appropriate objects. Note that this requires that the ifIndex value assigned to an interface must be unchanged even if the test causes a reboot. An agent must reject any test for which it cannot, perhaps due to resource constraints, make available at least the minimum amount of information after that test completes.
OID ifTestType	1.3.6.1.2.1.31.1.3.1.3	AutonomousType	read-write	A control variable used to start and stop operator- initiated interface tests. Most OBJECT IDENTIFIER values assigned to tests are defined elsewhere, in association with specific types of interface. However, this document assigns a value for a full-duplex loopback test, and defines the special meanings of the subject identifier: noTest OBJECT IDENTIFIER ::= { 0 0 } When the value noTest is written to this object, no action is taken unless a test is in progress, in which case the test is aborted. Writing any other value to this object is only valid when no test is currently in progress, in which case the indicated test is initiated. When read, this object always returns the most recent value that ifTestType was set to. If it has not been set since the last initialization of the network management subsystem on the agent, a value of noTest is returned.
IAN ifType	1.3.6.1.2.1.2.2.1.3	IANAifType	read-only	The type of interface. Additional values for ifType are assigned by the Internet Assigned Numbers Authority (IANA), through updating the syntax of the IANAifType textual convention.
ifVHCPacketGroup	1.3.6.1.2.1.31.2.1.6			A collection of objects providing information specific to higher speed (greater than 650,000,000 bits/second) packet- oriented network interfaces.
ifXEntry	1.3.6.1.2.1.31.1.1.1		not-accessible	An entry containing additional management information applicable to a particular interface.
ifXTable	1.3.6.1.2.1.31.1.1		not-accessible	A list of interface entries. The number of entries is given by the value of ifNumber. This table contains additional objects for the interface table.
interfaces	1.3.6.1.2.1.2
NTF linkDown	1.3.6.1.6.3.1.1.5.3			A linkDown trap signifies that the SNMP entity, acting in an agent role, has detected that the ifOperStatus object for one of its communication links is about to enter the down state from some other state (but not from the notPresent state). This other state is indicated by the included value of ifOperStatus.
NTF linkUp	1.3.6.1.6.3.1.1.5.4			A linkUp trap signifies that the SNMP entity, acting in an agent role, has detected that the ifOperStatus object for one of its communication links left the down state and transitioned into some other state (but not into the notPresent state). This other state is indicated by the included value of ifOperStatus.
linkUpDownNotificationsGroup	1.3.6.1.2.1.31.2.1.14			The notifications which indicate specific changes in the value of ifOperStatus.

RFC description

Defines managed objects for network interfaces as standardized in RFC 2863, covering interface counters, operational status, speed, and administrative parameters for both generic and sub-layer-specific interface management.

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