Network Working Group S. Waldbusser Request for Comments: 1271 Carnegie Mellon University November 1991 Remote Network Monitoring Management Information Base Status of this Memo This memo is an extension to the SNMP MIB. This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited. Table of Contents 1. Abstract .............................................. 2 2. The Network Management Framework....................... 2 3. Objects ............................................... 2 3.1 Format of Definitions ................................ 3 4. Overview .............................................. 3 4.1 Remote Network Management Goals ...................... 3 4.2 Textual Conventions .................................. 5 4.3 Structure of MIB ..................................... 5 4.3.1 The Statistics Group ............................... 6 4.3.2 The History Group .................................. 6 4.3.3 The Alarm Group .................................... 6 4.3.4 The Host Group ..................................... 6 4.3.5 The HostTopN Group ................................. 6 4.3.6 The Matrix Group ................................... 7 4.3.7 The Filter Group ................................... 7 4.3.8 The Packet Capture Group ........................... 7 4.3.9 The Event Group .................................... 7 5. Control of Remote Network Monitoring Devices .......... 7 5.1 Resource Sharing Among Multiple Management Stations .. 8 5.2 Row Addition Among Multiple Management Stations ...... 9 6. Definitions ........................................... 10 7. Acknowledgments ....................................... 80 8. References ............................................ 80 Security Considerations................................... 81 Author's Address.......................................... 81 Remote Network Monitoring Working Group [Page 1] RFC 1271 Remote Network Monitoring MIB November 1991 1. Abstract This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP-based internets. In particular, it defines objects for managing remote network monitoring devices. 2. The Network Management Framework The Internet-standard Network Management Framework consists of three components. They are: RFC 1155 which defines the SMI, the mechanisms used for describing and naming objects for the purpose of management. RFC 1212 defines a more concise description mechanism, which is wholly consistent with the SMI. RFC 1156 which defines MIB-I, the core set of managed objects for the Internet suite of protocols. RFC 1213, defines MIB-II, an evolution of MIB-I based on implementation experience and new operational requirements. RFC 1157 which defines the SNMP, the protocol used for network access to managed objects. The Framework permits new objects to be defined for the purpose of experimentation and evaluation. 3. Objects Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the subset of Abstract Syntax Notation One (ASN.1) [7] defined in the SMI. In particular, each object has a name, a syntax, and an encoding. The name is an object identifier, an administratively assigned name, which specifies an object type. The object type together with an object instance serves to uniquely identify a specific instantiation of the object. For human convenience, we often use a textual string, termed the OBJECT DESCRIPTOR, to also refer to the object type. The syntax of an object type defines the abstract data structure corresponding to that object type. The ASN.1 language is used for this purpose. However, the SMI [3] purposely restricts the ASN.1 constructs which may be used. These restrictions are explicitly made for simplicity. The encoding of an object type is simply how that object type Remote Network Monitoring Working Group [Page 2] RFC 1271 Remote Network Monitoring MIB November 1991 is represented using the object type's syntax. Implicitly tied to the notion of an object type's syntax and encoding is how the object type is represented when being transmitted on the network. The SMI specifies the use of the basic encoding rules of ASN.1 [8], subject to the additional requirements imposed by the SNMP. 3.1. Format of Definitions Section 6 contains the specification of all object types contained in this MIB module. The object types are defined using the conventions defined in the SMI, as amended by the extensions specified in [9,10]. 4. Overview Remote network monitoring devices are instruments that exist for the purpose of managing a network. Often these remote probes are stand-alone devices and devote significant internal resources for the sole purpose of managing a network. An organization may employ many of these devices, one per network segment, to manage its internet. In addition, these devices may be used for a network management service provider to access a client network, often geographically remote. While many of the objects in this document are suitable for the management of any type of network, there are some which are specific to managing Ethernet networks. The design of this MIB allows similar objects to be defined for other network types. It is intended that future versions of this document will define extensions for other network types such as Token Ring and FDDI. 4.1. Remote Network Management Goals o Offline Operation There are sometimes conditions when a management station will not be in constant contact with its remote monitoring devices. This is sometimes by design in an attempt to lower communications costs (especially when communicating over a WAN or dialup link), or by accident as network failures affect the communications between the management station and the probe. For this reason, this MIB allows a probe to be configured to perform diagnostics and to collect statistics continuously, even when communication with the management station may not be possible or Remote Network Monitoring Working Group [Page 3] RFC 1271 Remote Network Monitoring MIB November 1991 efficient. The probe may then attempt to notify the management station when an exceptional condition occurs. Thus, even in circumstances where communication between management station and probe is not continuous, fault, performance, and configuration information may be continuously accumulated and communicated to the management station conveniently and efficiently. o Preemptive Monitoring Given the resources available on the monitor, it is potentially helpful for it continuously to run diagnostics and to log network performance. The monitor is always available at the onset of any failure. It can notify the management station of the failure and can store historical statistical information about the failure. This historical information can be played back by the management station in an attempt to perform further diagnosis into the cause of the problem. o Problem Detection and Reporting The monitor can be configured to recognize conditions, most notably error conditions, and continuously to check for them. When one of these conditions occurs, the event may be logged, and management stations may be notified in a number of ways. o Value Added Data Because a remote monitoring device represents a network resource dedicated exclusively to network management functions, and because it is located directly on the monitored portion of the network, the remote network monitoring device has the opportunity to add significant value to the data it collects. For instance, by highlighting those hosts on the network that generate the most traffic or errors, the probe can give the management station precisely the information it needs to solve a class of problems. o Multiple Managers An organization may have multiple management stations for different units of the organization, for different functions (e.g. engineering and operations), and in an attempt to provide disaster recovery. Because environments with multiple management stations are common, the remote network monitoring device has to Remote Network Monitoring Working Group [Page 4] RFC 1271 Remote Network Monitoring MIB November 1991 deal with more than own management station, potentially using its resources concurrently. 4.2. Textual Conventions Two new data types are introduced as a textual convention in this MIB document. These textual conventions enhance the readability of the specification and can ease comparison with other specifications if appropriate. It should be noted that the introduction of the these textual conventions has no effect on either the syntax nor the semantics of any managed objects. The use of these is merely an artifact of the explanatory method used. Objects defined in terms of one of these methods are always encoded by means of the rules that define the primitive type. Hence, no changes to the SMI or the SNMP are necessary to accommodate these textual conventions which are adopted merely for the convenience of readers and writers in pursuit of the elusive goal of clear, concise, and unambiguous MIB documents. The new data types are: OwnerString and EntryStatus. 4.3. Structure of MIB The objects are arranged into the following groups: - statistics - history - alarm - host - hostTopN - matrix - filter - packet capture - event These groups are the basic unit of conformance. If a remote monitoring device implements a group, then it must implement all objects in that group. For example, a managed agent that implements the host group must implement the hostControlTable, the hostTable and the hostTimeTable. Remote Network Monitoring Working Group [Page 5] RFC 1271 Remote Network Monitoring MIB November 1991 All groups in this MIB are optional. Implementations of this MIB must also implement the system and interfaces group of MIB-II [6]. MIB-II may also mandate the implementation of additional groups. These groups are defined to provide a means of assigning object identifiers, and to provide a method for managed agents to know which objects they must implement. 4.3.1. The Statistics Group The statistics group contains statistics measured by the probe for each monitored interface on this device. This group currently consists of the etherStatsTable but in the future will contain tables for other media types including Token Ring and FDDI. 4.3.2. The History Group The history group records periodic statistical samples from a network and stores them for later retrieval. This group currently consists of the historyControlTable and the etherHistoryTable. In future versions of the MIB, this group may contain tables for other media types including Token Ring and FDDI. 4.3.3. The Alarm Group The alarm group periodically takes statistical samples from variables in the probe and compares them to previously configured thresholds. If the monitored variable crosses a threshold, an event is generated. A hysteresis mechanism is implemented to limit the generation of alarms. This group consists of the alarmTable and requires the implementation of the event group. 4.3.4. The Host Group The host group contains statistics associated with each host discovered on the network. This group discovers hosts on the network by keeping a list of source and destination MAC Addresses seen in good packets promiscuously received from the network. This group consists of the hostControlTable, the hostTable, and the hostTimeTable. 4.3.5. The HostTopN Group The hostTopN group is used to prepare reports that describe the hosts that top a list ordered by one of their statistics. The available statistics are samples of one of their base statistics over an interval specified by the management station. Thus, these statistics are rate based. The management station also selects how many such Remote Network Monitoring Working Group [Page 6] RFC 1271 Remote Network Monitoring MIB November 1991 hosts are reported. This group consists of the hostTopNControlTable and the hostTopNTable, and requires the implementation of the host group. 4.3.6. The Matrix Group The matrix group stores statistics for conversations between sets of two addresses. As the device detects a new conversation, it creates a new entry in its tables. This group consists of the matrixControlTable, the matrixSDTable and the matrixDSTable. 4.3.7. The Filter Group The filter group allows packets to be matched by a filter equation. These matched packets form a data stream that may be captured or may generate events. This group consists of the filterTable and the channelTable. 4.3.8. The Packet Capture Group The Packet Capture group allows packets to be captured after they flow through a channel. This group consists of the bufferControlTable and the captureBufferTable, and requires the implementation of the filter group. 4.3.9. The Event Group The event group controls the generation and notification of events from this device. This group consists of the eventTable and the logTable. 5. Control of Remote Network Monitoring Devices Due to the complex nature of the available functions in these devices, the functions often need user configuration. In many cases, the function requires parameters to be set up for a data collection operation. The operation can proceed only after these parameters are fully set up. Many functional groups in this MIB have one or more tables in which to set up control parameters, and one or more data tables in which to place the results of the operation. The control tables are typically read-write in nature, while the data tables are typically read-only. Because the parameters in the control table often describe resulting data in the data table, many of the parameters can be modified only when the control entry is invalid. Thus, the method for modifying these parameters is to invalidate the control entry, causing its deletion and the deletion of any associated data entries, and then Remote Network Monitoring Working Group [Page 7] RFC 1271 Remote Network Monitoring MIB November 1991 create a new control entry with the proper parameters. Deleting the control entry also gives a convenient method for reclaiming the resources used by the associated data. Some objects in this MIB provide a mechanism to execute an action on the remote monitoring device. These objects may execute an action as a result of a change in the state of the object. For those objects in this MIB, a request to set an object to the same value as it currently holds would thus cause no action to occur. To facilitate control by multiple managers, resources have to be shared among the managers. These resources are typically the memory and computation resources that a function requires. 5.1. Resource Sharing Among Multiple Management Stations When multiple management stations wish to use functions that compete for a finite amount of resources on a device, a method to facilitate this sharing of resources is required. Potential conflicts include: o Two management stations wish to simultaneously use resources that together would exceed the capability of the device. o A management station uses a significant amount of resources for a long period of time. o A management station uses resources and then crashes, forgetting to free the resources so others may use them. A mechanism is provided for each management station initiated function in this MIB to avoid these conflicts and to help resolve them when they occur. Each function has a label identifying the initiator (owner) of the function. This label is set by the initiator to provide for the following possibilities: o A management station may recognize resources it owns and no longer needs. o A network operator can find the management station that owns the resource and negotiate for it to be freed. o A network operator may decide to unilaterally free resources another network operator has reserved. o Upon initialization, a management station may recognize resources it had reserved in the past. With this Remote Network Monitoring Working Group [Page 8] RFC 1271 Remote Network Monitoring MIB November 1991 information it may free the resources if it no longer needs them. Management stations and probes should support any format of the owner string dictated by the local policy of the organization. It is suggested that this name contain one or more of the following: IP address, management station name, network manager's name, location, or phone number. This information will help users to share the resources more effectively. There is often default functionality that the device wishes to set up. The resources associated with this functionality are then owned by the device itself. In this case, the device will set the relevant owner object to a string starting with 'monitor'. Indiscriminate modification of the monitor-owned configuration by network management stations is discouraged. In fact, a network management station should only modify these objects under the direction of the administrator of the probe, often the network administrator. When a network management station wishes to utilize a function in a monitor, it is encouraged to first scan the control table of that function to find an instance with similar parameters to share. This is especially true for those instances owned by the monitor, which can be assumed to change infrequently. If a management station decides to share an instance owned by another management station, it should understand that the management station that owns the instance may indiscriminately modify or delete it. 5.2. Row Addition Among Multiple Management Stations The addition of new rows is achieved using the method described in [9]. In this MIB, rows are often added to a table in order to configure a function. This configuration usually involves parameters that control the operation of the function. The agent must check these parameters to make sure they are appropriate given restrictions defined in this MIB as well as any implementation specific restrictions such as lack of resources. The agent implementor may be confused as to when to check these parameters and when to signal to the management station that the parameters are invalid. There are two opportunities: o When the management station sets each parameter object. o When the management station sets the entry status object to valid. If the latter is chosen, it would be unclear to the management station which of the several parameters was invalid and caused the Remote Network Monitoring Working Group [Page 9] RFC 1271 Remote Network Monitoring MIB November 1991 badValue error to be emitted. Thus, wherever possible, the implementor should choose the former as it will provide more information to the management station. A problem can arise when multiple management stations attempt to set configuration information simultaneously using SNMP. When this involves the addition of a new conceptual row in the same control table, the managers may collide, attempting to create the same entry. To guard against these collisions, each such control entry contains a status object with special semantics that help to arbitrate among the managers. If an attempt is made with the row addition mechanism to create such a status object and that object already exists, an error is returned. When more than one manager simultaneously attempts to create the same conceptual row, only the first will succeed. The others will receive an error. 6. Definitions RFC1271-MIB DEFINITIONS ::= BEGIN IMPORTS Counter FROM RFC1155-SMI DisplayString FROM RFC1158-MIB mib-2 FROM RFC1213-MIB OBJECT-TYPE FROM RFC-1212; -- This MIB module uses the extended OBJECT-TYPE macro as -- defined in [9]. -- Remote Network Monitoring MIB rmon OBJECT IDENTIFIER ::= { mib-2 16 } -- textual conventions OwnerString ::= DisplayString -- This data type is used to model an administratively -- assigned name of the owner of a resource. This -- information is taken from the NVT ASCII character set. -- It is suggested that this name contain one or more -- of the following: -- IP address, management station name, network manager's -- name, location, or phone number. -- In some cases the agent itself will be the owner of -- an entry. In these cases, this string shall be set -- to a string starting with 'monitor'. Remote Network Monitoring Working Group [Page 10] RFC 1271 Remote Network Monitoring MIB November 1991 -- -- SNMP access control is articulated entirely in terms of -- the contents of MIB views; access to a particular SNMP -- object instance depends only upon its presence or -- absence in a particular MIB view and never upon its -- value or the value of related object instances. Thus, -- objects of this type afford resolution of resource -- contention only among cooperating managers; they -- realize no access control function with respect -- to uncooperative parties. -- -- By convention, objects with this syntax are declared -- as having -- -- SIZE (0..127) EntryStatus ::= INTEGER { valid(1), createRequest(2), underCreation(3), invalid(4) } -- The status of a table entry. -- -- Setting this object to the value invalid(4) has the -- effect of invalidating the corresponding entry. -- That is, it effectively disassociates the mapping -- identified with said entry. -- It is an implementation-specific matter as to whether -- the agent removes an invalidated entry from the table. -- Accordingly, management stations must be prepared to -- receive tabular information from agents that corresponds -- to entries currently not in use. Proper -- interpretation of such entries requires examination -- of the relevant EntryStatus object. -- -- An existing instance of this object cannot be set to -- createRequest(2). This object may only be set to -- createRequest(2) when this instance is created. When -- this object is created, the agent may wish to create -- supplemental object instances to complete a conceptual -- row in this table. Immediately after completing the -- create operation, the agent must set this object to -- underCreation(3). -- -- Entries shall exist in the underCreation(3) state until Remote Network Monitoring Working Group [Page 11] RFC 1271 Remote Network Monitoring MIB November 1991 -- the management station is finished configuring the -- entry and sets this object to valid(1) or aborts, -- setting this object to invalid(4). If the agent -- determines that an entry has been in the -- underCreation(3) state for an abnormally long time, -- it may decide that the management station has -- crashed. If the agent makes this decision, -- it may set this object to invalid(4) to reclaim the -- entry. A prudent agent will understand that the -- management station may need to wait for human input -- and will allow for that possibility in its -- determination of this abnormally long period. statistics OBJECT IDENTIFIER ::= { rmon 1 } history OBJECT IDENTIFIER ::= { rmon 2 } alarm OBJECT IDENTIFIER ::= { rmon 3 } hosts OBJECT IDENTIFIER ::= { rmon 4 } hostTopN OBJECT IDENTIFIER ::= { rmon 5 } matrix OBJECT IDENTIFIER ::= { rmon 6 } filter OBJECT IDENTIFIER ::= { rmon 7 } capture OBJECT IDENTIFIER ::= { rmon 8 } event OBJECT IDENTIFIER ::= { rmon 9 } -- The Statistics Group -- -- Implementation of the Statistics group is optional. -- -- The statistics group contains statistics measured by the -- probe for each monitored interface on this device. These -- statistics take the form of free running counters that -- start from zero when a valid entry is created. -- -- This group currently has statistics defined only for -- Ethernet interfaces. Each etherStatsEntry contains -- statistics for one Ethernet interface. The probe must -- create one etherStats entry for each monitored Ethernet -- interface on the device. etherStatsTable OBJECT-TYPE SYNTAX SEQUENCE OF EtherStatsEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A list of Ethernet statistics entries." ::= { statistics 1 } Remote Network Monitoring Working Group [Page 12] RFC 1271 Remote Network Monitoring MIB November 1991 etherStatsEntry OBJECT-TYPE SYNTAX EtherStatsEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A collection of statistics kept for a particular Ethernet interface." INDEX { etherStatsIndex } ::= { etherStatsTable 1 } EtherStatsEntry ::= SEQUENCE { etherStatsIndex INTEGER (1..65535), etherStatsDataSource OBJECT IDENTIFIER, etherStatsDropEvents Counter, etherStatsOctets Counter, etherStatsPkts Counter, etherStatsBroadcastPkts Counter, etherStatsMulticastPkts Counter, etherStatsCRCAlignErrors Counter, etherStatsUndersizePkts Counter, etherStatsOversizePkts Counter, etherStatsFragments Counter, etherStatsJabbers Counter, etherStatsCollisions Counter, etherStatsPkts64Octets Counter, etherStatsPkts65to127Octets Counter, etherStatsPkts128to255Octets Counter, etherStatsPkts256to511Octets Counter, etherStatsPkts512to1023Octets Counter, etherStatsPkts1024to1518Octets Counter, etherStatsOwner OwnerString, etherStatsStatus INTEGER } etherStatsIndex OBJECT-TYPE SYNTAX INTEGER (1..65535) ACCESS read-only STATUS mandatory DESCRIPTION "The value of this object uniquely identifies this etherStats entry." ::= { etherStatsEntry 1 } etherStatsDataSource OBJECT-TYPE SYNTAX OBJECT IDENTIFIER ACCESS read-write STATUS mandatory DESCRIPTION Remote Network Monitoring Working Group [Page 13] RFC 1271 Remote Network Monitoring MIB November 1991 "This object identifies the source of the data that this etherStats entry is configured to analyze. This source can be any ethernet interface on this device. In order to identify a particular interface, this object shall identify the instance of the ifIndex object, defined in [4,6], for the desired interface. For example, if an entry were to receive data from interface #1, this object would be set to ifIndex.1. The statistics in this group reflect all packets on the local network segment attached to the identified interface. This object may not be modified if the associated etherStatsStatus object is equal to valid(1)." ::= { etherStatsEntry 2 } etherStatsDropEvents OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of events in which packets were dropped by the probe due to lack of resources. Note that this number is not necessarily the number of packets dropped; it is just the number of times this condition has been detected." ::= { etherStatsEntry 3 } etherStatsOctets OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of octets of data (including those in bad packets) received on the network (excluding framing bits but including FCS octets)." ::= { etherStatsEntry 4 } etherStatsPkts OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets (including error packets) received." ::= { etherStatsEntry 5 } Remote Network Monitoring Working Group [Page 14] RFC 1271 Remote Network Monitoring MIB November 1991 etherStatsBroadcastPkts OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of good packets received that were directed to the broadcast address." ::= { etherStatsEntry 6 } etherStatsMulticastPkts OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of good packets received that were directed to a multicast address. Note that this number does not include packets directed to the broadcast address." ::= { etherStatsEntry 7 } etherStatsCRCAlignErrors OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets received that had a length (excluding framing bits, but including FCS octets) of between 64 and 1518 octets, inclusive, but were not an integral number of octets in length or had a bad Frame Check Sequence (FCS)." ::= { etherStatsEntry 8 } etherStatsUndersizePkts OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets received that were less than 64 octets long (excluding framing bits, but including FCS octets) and were otherwise well formed." ::= { etherStatsEntry 9 } etherStatsOversizePkts OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory Remote Network Monitoring Working Group [Page 15] RFC 1271 Remote Network Monitoring MIB November 1991 DESCRIPTION "The total number of packets received that were longer than 1518 octets (excluding framing bits, but including FCS octets) and were otherwise well formed." ::= { etherStatsEntry 10 } etherStatsFragments OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets received that were not an integral number of octets in length or that had a bad Frame Check Sequence (FCS), and were less than 64 octets in length (excluding framing bits but including FCS octets)." ::= { etherStatsEntry 11 } etherStatsJabbers OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets received that were longer than 1518 octets (excluding framing bits, but including FCS octets), and were not an integral number of octets in length or had a bad Frame Check Sequence (FCS)." ::= { etherStatsEntry 12 } etherStatsCollisions OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The best estimate of the total number of collisions on this Ethernet segment." ::= { etherStatsEntry 13 } etherStatsPkts64Octets OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets (including error packets) received that were 64 octets in length (excluding framing bits but including FCS octets)." Remote Network Monitoring Working Group [Page 16] RFC 1271 Remote Network Monitoring MIB November 1991 ::= { etherStatsEntry 14 } etherStatsPkts65to127Octets OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets (including error packets) received that were between 65 and 127 octets in length inclusive (excluding framing bits but including FCS octets)." ::= { etherStatsEntry 15 } etherStatsPkts128to255Octets OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets (including error packets) received that were between 128 and 255 octets in length inclusive (excluding framing bits but including FCS octets)." ::= { etherStatsEntry 16 } etherStatsPkts256to511Octets OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets (including error packets) received that were between 256 and 511 octets in length inclusive (excluding framing bits but including FCS octets)." ::= { etherStatsEntry 17 } etherStatsPkts512to1023Octets OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets (including error packets) received that were between 512 and 1023 octets in length inclusive (excluding framing bits but including FCS octets)." ::= { etherStatsEntry 18 } Remote Network Monitoring Working Group [Page 17] RFC 1271 Remote Network Monitoring MIB November 1991 etherStatsPkts1024to1518Octets OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of packets (including error packets) received that were between 1024 and 1518 octets in length inclusive (excluding framing bits but including FCS octets)." ::= { etherStatsEntry 19 } etherStatsOwner OBJECT-TYPE SYNTAX OwnerString ACCESS read-write STATUS mandatory DESCRIPTION "The entity that configured this entry and is therefore using the resources assigned to it." ::= { etherStatsEntry 20 } etherStatsStatus OBJECT-TYPE SYNTAX EntryStatus ACCESS read-write STATUS mandatory DESCRIPTION "The status of this etherStats entry." ::= { etherStatsEntry 21 } -- The History Group -- Implementation of the History group is optional. -- -- The history group records periodic statistical samples from -- a network and stores them for later retrieval. The -- historyControl table stores configuration entries that each -- define an interface, polling period, and other parameters. -- Once samples are taken, their data is stored in an entry -- in a media-specific table. Each such entry defines one -- sample, and is associated with the historyControlEntry that -- caused the sample to be taken. Currently the only media- -- specific table defined is the etherHistoryTable, for -- Ethernet networks. -- -- If the probe keeps track of the time of day, it should -- start the first sample of the history at a time such that -- when the next hour of the day begins, a sample is -- started at that instant. This tends to make more Remote Network Monitoring Working Group [Page 18] RFC 1271 Remote Network Monitoring MIB November 1991 -- user-friendly reports, and enables comparison of reports -- from different probes that have relatively accurate time -- of day. -- -- The monitor is encouraged to add two history control entries -- per monitored interface upon initialization that describe -- a short term and a long term polling period. Suggested -- parameters are 30 seconds for the short term polling -- period and 30 minutes for the long term period. historyControlTable OBJECT-TYPE SYNTAX SEQUENCE OF HistoryControlEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A list of history control entries." ::= { history 1 } historyControlEntry OBJECT-TYPE SYNTAX HistoryControlEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A list of parameters that set up a periodic sampling of statistics." INDEX { historyControlIndex } ::= { historyControlTable 1 } HistoryControlEntry ::= SEQUENCE { historyControlIndex INTEGER (1..65535), historyControlDataSource OBJECT IDENTIFIER, historyControlBucketsRequested INTEGER (1..65535), historyControlBucketsGranted INTEGER (1..65535), historyControlInterval INTEGER (1..3600), historyControlOwner OwnerString, historyControlStatus INTEGER } historyControlIndex OBJECT-TYPE SYNTAX INTEGER (1..65535) ACCESS read-only STATUS mandatory DESCRIPTION "An index that uniquely identifies an entry in the historyControl table. Each such entry defines a set of samples at a particular interval for an interface on the device." ::= { historyControlEntry 1 } Remote Network Monitoring Working Group [Page 19] RFC 1271 Remote Network Monitoring MIB November 1991 historyControlDataSource OBJECT-TYPE SYNTAX OBJECT IDENTIFIER ACCESS read-write STATUS mandatory DESCRIPTION "This object identifies the source of the data for which historical data was collected and placed in a media-specific table on behalf of this historyControlEntry. This source can be any interface on this device. In order to identify a particular interface, this object shall identify the instance of the ifIndex object, defined in [4,6], for the desired interface. For example, if an entry were to receive data from interface #1, this object would be set to ifIndex.1. The statistics in this group reflect all packets on the local network segment attached to the identified interface. This object may not be modified if the associated historyControlStatus object is equal to valid(1)." ::= { historyControlEntry 2 } historyControlBucketsRequested OBJECT-TYPE SYNTAX INTEGER (1..65535) ACCESS read-write STATUS mandatory DESCRIPTION "The requested number of discrete time intervals over which data is to be saved in the part of the media-specific table associated with this historyControl entry. When this object is created or modified, the probe should set historyControlBucketsGranted as closely to this object as is possible for the particular probe implementation and available resources." DEFVAL { 50 } ::= { historyControlEntry 3 } historyControlBucketsGranted OBJECT-TYPE SYNTAX INTEGER (1..65535) ACCESS read-only STATUS mandatory DESCRIPTION "The number of discrete sampling intervals over which data shall be saved in the part of Remote Network Monitoring Working Group [Page 20] RFC 1271 Remote Network Monitoring MIB November 1991 the media-specific table associated with this historyControl entry. When the associated historyControlBucketsRequested object is created or modified, the probe should set this object as closely to the requested value as is possible for the particular probe implementation and available resources. The probe must not lower this value except as a result of a modification to the associated historyControlBucketsRequested object. There will be times when the actual number of buckets associated with this entry is less than the value of this object. In this case, at the end of each sampling interval, a new bucket will be added to the media-specific table. When the number of buckets reaches the value of this object and a new bucket is to be added to the media-specific table, the oldest bucket associated with this historyControlEntry shall be deleted by the agent so that the new bucket can be added. When the value of this object changes to a value less than the current value, entries are deleted from the media-specific table associated with this historyControlEntry. Enough of the oldest of these entries shall be deleted by the agent so that their number remains less than or equal to the new value of this object. When the value of this object changes to a value greater than the current value, the number of associated media-specific entries may be allowed to grow." ::= { historyControlEntry 4 } historyControlInterval OBJECT-TYPE SYNTAX INTEGER (1..