Each entry contains one NetworkAddress to`physical' address equivalence.

The Address Translation tables contain theNetworkAddress to `physical' address equivalences.Some interfaces do not use translation tables fordetermining address equivalences (e.g., DDN-X.25has an algorithmic method); if all interfaces areof this type, then the Address Translation tableis empty, i.e., has zero entries.

Information about this entity's relationship witha particular EGP neighbor.

The EGP neighbor table.

A (conceptual) entry for one device contained by thehost.As an example, an instance of the hrDeviceTypeobject might be named hrDeviceType.3

The (conceptual) table of devices contained by thehost.

A (conceptual) entry for one long-term storage devicecontained by the host.The hrDeviceIndex in the indexrepresents the entry in the hrDeviceTable thatcorresponds to the hrDiskStorageEntry. As an example,an instance of the hrDiskStorageCapacity object mightbe named hrDiskStorageCapacity.3

The (conceptual) table of long-term storage devicescontained by the host.In particular, disk devicesaccessed remotely over a network are not includedhere.Note that this table is potentially sparse: a(conceptual) entry exists only if the correspondentvalue of the hrDeviceType object is`hrDeviceDiskStorage'.

A (conceptual) entry for one file system local tothis host or remotely mounted from a file server.File systems that are in only one user's environmenton a multi-user system will not be included in thistable.As an example of how objects in this table are named,an instance of the hrFSMountPoint object might benamed hrFSMountPoint.3

The (conceptual) table of file systems local to thishost or remotely mounted from a file server.Filesystems that are in only one user's environment on amulti-user system will not be included in this table.

A (conceptual) entry for one network device containedby the host.The hrDeviceIndex in the indexrepresents the entry in the hrDeviceTable thatcorresponds to the hrNetworkEntry.As an example of how objects in this table are named,an instance of the hrNetworkIfIndex object might benamed hrNetworkIfIndex.3

The (conceptual) table of network devices containedby the host.Note that this table is potentially sparse: a(conceptual) entry exists only if the correspondentvalue of the hrDeviceType object is`hrDeviceNetwork'.

A (conceptual) entry for one partition.ThehrDeviceIndex in the index represents the entry in thehrDeviceTable that corresponds to thehrPartitionEntry.As an example of how objects in this table are named,an instance of the hrPartitionSize object might benamed hrPartitionSize.3.1

The (conceptual) table of partitions for long-termstorage devices contained by the host.In particular,partitions accessed remotely over a network are notincluded here.

A (conceptual) entry for one printer local to thehost.The hrDeviceIndex in the index represents theentry in the hrDeviceTable that corresponds to thehrPrinterEntry.As an example of how objects in this table are named,an instance of the hrPrinterStatus object might benamed hrPrinterStatus.3

The (conceptual) table of printers local to the host.Note that this table is potentially sparse: a(conceptual) entry exists only if the correspondentvalue of the hrDeviceType object is`hrDevicePrinter'.

A (conceptual) entry for one processor contained bythe host.The hrDeviceIndex in the index representsthe entry in the hrDeviceTable that corresponds to thehrProcessorEntry.As an example of how objects in this table are named,an instance of the hrProcessorFrwID object might benamed hrProcessorFrwID.3

The (conceptual) table of processors contained by thehost.Note that this table is potentially sparse: a(conceptual) entry exists only if the correspondentvalue of the hrDeviceType object is`hrDeviceProcessor'.

A (conceptual) entry for one logical storage area onthe host.As an example, an instance of thehrStorageType object might be named hrStorageType.3

The (conceptual) table of logical storage areas onthe host.An entry shall be placed in the storage table for eachlogical area of storage that is allocated and hasfixed resource limits.The amount of storagerepresented in an entity is the amount actually usableby the requesting entity, and excludes loss due toformatting or file system reference information.These entries are associated with logical storageareas, as might be seen by an application, rather thanphysical storage entities which are typically seen byan operating system.Storage such as tapes andfloppies without file systems on them are typicallynot allocated in chunks by the operating system torequesting applications, and therefore shouldn'tappear in this table.Examples of valid storage forthis table include disk partitions, file systems, ram(for some architectures this is further segmented intoregular memory, extended memory, and so on), backingstore for virtual memory (`swap space').This table is intended to be a useful diagnostic for`out of memory' and `out of buffers' types offailures.In addition, it can be a useful performancemonitoring tool for tracking memory, disk, or bufferusage.

A (conceptual) entry for a piece of softwareinstalled on this host.As an example of how objects in this table are named,an instance of the hrSWInstalledName object might benamed hrSWInstalledName.96

The (conceptual) table of software installed on thishost.

A (conceptual) entry for one piece of softwarerunning on the host Note that because the installedsoftware table only contains information for softwarestored locally on this host, not every piece ofrunning software will be found in the installedsoftware table.This is true of software that wasloaded and run from a non-local source, such as anetwork-mounted file system.As an example of how objects in this table are named,an instance of the hrSWRunName object might be namedhrSWRunName.1287

A (conceptual) entry containing software performancemetrics.As an example, an instance of thehrSWRunPerfCPU object might be namedhrSWRunPerfCPU.1287

The (conceptual) table of running softwareperformance metrics.

The (conceptual) table of software running on thehost.

An interface entry containing objects at thesubnetwork layer and below for a particularinterface.

A list of objects identifying an address for which thesystem will accept packets/frames on the particularinterface identified by the index value ifIndex.

This table contains an entry for each address (broadcast,multicast, or uni-cast) for which the system will receivepackets/frames on a particular interface, except as follows:- for an interface operating in promiscuous mode, entriesare only required for those addresses for which the systemwould receive frames were it not operating in promiscuousmode.- for 802.5 functional addresses, only one entry isrequired, for the address which has the functional addressbit ANDed with the bit mask of all functional addresses forwhich the interface will accept frames.A system is normally able to use any unicast address whichcorresponds to an entry in this table as a source address.

Information on a particular relationship between two sub-layers, specifying that one sub-layer runs on 'top' of theother sub-layer.Each sub-layer corresponds to a conceptualrow in the ifTable.

The table containing information on the relationshipsbetween the multiple sub-layers of network interfaces.Inparticular, it contains information on which sub-layers run'on top of' which other sub-layers, where each sub-layercorresponds to a conceptual row in the ifTable.Forexample, when the sub-layer with ifIndex value x runs overthe sub-layer with ifIndex value y, then this tablecontains:ifStackStatus.x.y=activeFor each ifIndex value, I, which identifies an activeinterface, there are always at least two instantiated rowsin this table associated with I.For one of these rows, Iis the value of ifStackHigherLayer; for the other, I is thevalue of ifStackLowerLayer.(If I is not involved inmultiplexing, then these are the only two rows associatedwith I.)For example, two rows exist even for an interface which hasno others stacked on top or below it:ifStackStatus.0.x=activeifStackStatus.x.0=active

A list of interface entries.The number ofentries is given by the value of ifNumber.

An entry containing objects for invoking tests on aninterface.

This table contains one entry per interface.It definesobjects which allow a network manager to instruct an agentto test an interface for various faults.Tests for aninterface are defined in the media-specific MIB for thatinterface.After invoking a test, the object ifTestResultcan be read to determine the outcome.If an agent can notperform the test, ifTestResult is set to so indicate.Theobject ifTestCode can be used to provide further test-specific or interface-specific (or even enterprise-specific)information concerning the outcome of the test.Only onetest can be in progress on each interface at any one time.If one test is in progress when another test is invoked, thesecond test is rejected.Some agents may reject a test whena 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 theinterface to be tested.This is accomplished with theifTestId 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 delayget (ifTestId, ifTestStatus)}/* * Is not being used right now -- let's compete * to see who gets it. */lock_value = ifTestIdif ( 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 ifTestResultwhen test completes, agent sets ifTestResult agent also sets ifTestStatus = 'notInUse'retrieve any additional test results, and ifTestIdif (ifTestId == lock_value+1) results are validA manager station first retrieves the value of theappropriate ifTestId and ifTestStatus objects, periodicallyrepeating the retrieval if necessary, until the value ofifTestStatus is 'notInUse'.The manager station then triesto set the same ifTestId object to the value it justretrieved, the same ifTestStatus object to 'inUse', and thecorresponding ifTestOwner object to a value indicatingitself.If the set operation succeeds then the manager hasobtained ownership of the ifTestEntry, and the value of theifTestId object is incremented by the agent (per thesemantics of TestAndIncr).Failure of the set operationindicates that some other manager has obtained ownership ofthe ifTestEntry.Once ownership is obtained, any test parameters can besetup, 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 theresults.In the (rare) event that the invocation of testsby two network managers were to overlap, then there would bea possibility that the first test's results might beoverwritten by the second test's results prior to the firstresults being read.This unlikely circumstance can bedetected by a network manager retrieving ifTestId at thesame time as retrieving the test results, and ensuring thatthe results are for the desired request.If ifTestType is not set within an abnormally long period oftime after ownership is obtained, the agent should time-outthe manager, and reset the value of the ifTestStatus objectback to 'notInUse'.It is suggested that this time-outperiod be 5 minutes.In general, a management station must not retransmit arequest to invoke a test for which it does not receive aresponse; instead, it properly inspects an agent's MIB todetermine if the invocation was successful.Only if theinvocation was unsuccessful, is the invocation requestretransmitted.Some tests may require the interface to be taken off-line inorder to execute them, or may even require the agent toreboot after completion of the test.In thesecircumstances, communication with the management stationinvoking the test may be lost until after completion of thetest.An agent is not required to support such tests.However, if such tests are supported, then the agent shouldmake every effort to transmit a response to the requestwhich invoked the test prior to losing communication.Whenthe agent is restored to normal service, the results of thetest are properly made available in the appropriate objects.Note that this requires that the ifIndex value assigned toan interface must be unchanged even if the test causes areboot.An agent must reject any test for which it cannot,perhaps due to resource constraints, make available at leastthe minimum amount of information after that testcompletes.

An entry containing additional management informationapplicable to a particular interface.

A list of interface entries.The number of entries isgiven by the value of ifNumber.This table containsadditional objects for the interface table.

The addressing information for one of thisentity's IP addresses.

The table of addressing information relevant tothis entity's IP addresses.

Each entry contains one IpAddress to `physical'address equivalence.

The IP Address Translation table used for mappingfrom IP addresses to physical addresses.

A route to a particular destination.

This entity's IP Routing table.

An entry (conceptual row) in the sysORTable.

The (conceptual) table listing the capabilities ofthe local SNMP application acting as a commandresponder with respect to various MIB modules.SNMP entities having dynamically-configurable supportof MIB modules will have a dynamically-varying numberof conceptual rows.

Information about a particular current TCPconnection.An object of this type is transient,in that it ceases to exist when (or soon after)the connection makes the transition to the CLOSEDstate.

A table containing TCP connection-specificinformation.

Information about a particular current UDPlistener.

A table containing UDP listener information.