This memo defines the second version of the Management Information Base (MIB-II) for use with network management protocols in TCP/IP- based internets. In particular, together with its companion memos which describe the structure of management information (RFC 1155) along with the network management protocol (RFC 1157) for TCP/IP- based internets, these documents provide a simple, workable architecture and system for managing TCP/IP-based internets and in particular the Internet community.
This document on MIB-II incorporates all of the technical content of RFC 1156 on MIB-I and extends it, without loss of compatibilty. However, MIB-I as described in RFC 1156 is full Standard Protocol of the Internet, while the MIB-II described here is Proposed Standard Protocol of the Internet.
This memo defines a mandatory extension to the base MIB (RFC 1156) and is a Proposed Standard for the Internet community. The extensions described here are currently Elective, but when they become a standard, they will have the same status as RFC 1156, that is, Recommended. The Internet Activities Board recommends that all IP and TCP implementations be network manageable. This implies implementation of the Internet MIB (RFC 1156 and the extensions in RFC 1158) and at least one of the two recommended management protocols SNMP (RFC 1157) or CMOT (RFC 1095).
This version of the MIB specification, MIB-II, is an incremental refinement of MIB-I. As such, it has been designed according to two criteria: first, changes have been made in response to new operational requirements in the Internet; and, second, the changes are entirely upwards compatible in order to minimize impact on the network as the managed nodes in the Internet transition from MIB-I to MIB-II.
It is expected that additional MIB groups and variables will be defined over time to accommodate the monitoring and control needs of new or changing components of the Internet.
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Please refer to the latest edition of the "IAB Official Protocol Standards" RFC for current information on the state and status of standard Internet protocols.
Distribution of this memo is unlimited.
Table of Contents
1. Status of this Memo .................................. 1 2. Introduction ......................................... 3 3. Changes from MIB-I ................................... 4 3.1 Deprecated Objects .................................. 4 3.2 Display Strings ..................................... 5 3.3 The System Group .................................... 5 3.4 The Interfaces Group ................................ 5 3.5 The Address Translation Group ....................... 6 3.6 The IP Group ........................................ 7 3.7 The ICMP Group ...................................... 7 3.8 The TCP Group ....................................... 7 3.9 The UDP Group ....................................... 7 3.10 The EGP Group ...................................... 8 3.11 The Transmission Group ............................. 8 3.12 The SNMP Group ..................................... 8 4. Objects .............................................. 8 4.1 Object Groups ....................................... 9 4.2 Format of Definitions ............................... 10 5. Object Definitions ................................... 10 5.1 The System Group .................................... 11 5.2 The Interfaces Group ................................ 14 5.2.1 The Interfaces table .............................. 15 5.3 The Address Translation Group ....................... 27 5.4 The IP Group ........................................ 30 5.4.1 The IP Address table .............................. 38 5.4.2 The IP Routing table .............................. 41 5.4.3 The IP Address Translation table .................. 48 5.5 The ICMP Group ...................................... 51 5.6 The TCP Group ....................................... 61 5.6.1 The TCP Connection table .......................... 66 5.6.2 Additional TCP Objects ............................ 69 5.7 The UDP Group ....................................... 70 5.7.1 The UDP Listener table ............................ 72 5.8 The EGP Group ....................................... 73 5.8.1 The EGP Neighbor table ............................ 75 5.8.2 Additional EGP variables .......................... 83 5.9 The Transmission Group .............................. 83 5.10 The SNMP Group ..................................... 83 6. Definitions .......................................... 95
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7. Identification of OBJECT instances for use with the SNMP ................................................. 126 7.1 ifTable Object Type Names ........................... 127 7.2 atTable Object Type Names ........................... 127 7.3 ipAddrTable Object Type Names ....................... 128 7.4 ipRoutingTable Object Type Names .................... 128 7.5 ipNetToMediaTable Object Type Names ................. 129 7.6 tcpConnTable Object Type Names ...................... 129 7.7 udpTable Object Type Names .......................... 130 7.8 egpNeighTable Object Type Names ..................... 130 8. Acknowledgements .................................... 130 9. References .......................................... 131 10. Security Considerations.............................. 133 11. Author's Address..................................... 133
As reported in RFC 1052, IAB Recommendations for the Development of Internet Network Management Standards [1], a two-prong strategy for network management of TCP/IP-based internets was undertaken. In the short-term, the Simple Network Management Protocol (SNMP) was to be used to manage nodes in the Internet community. In the long-term, the use of the OSI network management framework was to be examined. Two documents were produced to define the management information: RFC 1065, which defined the Structure of Management Information (SMI) [2], and RFC 1066, which defined the Management Information Base (MIB) [3]. Both of these documents were designed so as to be compatible with both the SNMP and the OSI network management framework.
This strategy was quite successful in the short-term: Internet-based network management technology was fielded, by both the research and commercial communities, within a few months. As a result of this, portions of the Internet community became network manageable in a timely fashion.
As reported in RFC 1109, Report of the Second Ad Hoc Network Management Review Group [4], the requirements of the SNMP and the OSI network management frameworks were more different than anticipated. As such, the requirement for compatibility between the SMI/MIB and both frameworks was suspended. This action permitted the operational network management framework, the SNMP, to respond to new operational needs in the Internet community by producing this document.
As such, the current network management framework for TCP/IP- based internets consists of: Structure and Identification of
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Management Information for TCP/IP-based internets, RFC 1155 [13], which describes how managed objects contained in the MIB are defined; Management Information Base for Network Management of TCP/IP-based internets (version 2), this memo, which describes the managed objects contained in the MIB; and, the Simple Network Management Protocol, RFC 1157 [14], which defines the protocol used to manage these objects.
Consistent with the IAB directive to produce simple, workable systems in the short-term, the list ofc objects (e.g., for BSD UNIX) were excluded.
7) It was agreed to avoid heavily instrumenting critical sections of code. The general guideline was one counter per critical section per layer.
In order to better prepare implementors for future changes in the MIB, a new term "deprecated" may be used when describing an object. A deprecated object in the MIB is one which must be supported, but one which will most likely be removed from the next version of the MIB (e.g., MIB-III).
MIB-II marks one object as being deprecated:
atTable
As a result of deprecating the atTable object, the entire Address Translation group is deprecated.
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Note that no functionality is lost with the deprecation of these objects: new objects providing equivalent or superior functionality are defined in MIB-II.
In the past, there have been misinterpretations of the MIB as to when a string of octets should contain printable characters, meant to be displayed to a human. As a textual convention in the MIB, the datatype
DisplayString ::= OCTET STRING
is introduced. A DisplayString is restricted to the NVT ASCII character set, as defined in pages 10-11 of [7].
The following objects are now defined in terms of DisplayString:
sysDescr ifDescr
It should be noted that this change has no effect on either the syntax nor semantics of these objects. The use of the DisplayString notation is merely an artifact of the explanatory method used in MIB-II and future MIBs.
Further, it should be noted that any object defined in terms of OCTET STRING may contain arbitrary binary data, in which each octet may take any value from 0 to 255 (decimal).
The definition of the ifNumber object was incorrect, as it required all interfaces to support IP. (For example, devices without IP, such as MAC-layer bridges, could not be managed if this definition was strictly followed.) The description of the ifNumber object is changed
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accordingly.
The ifTable object was mistaken marked as read-write, it has been (correctly) re-designated as read-only. In addition, several new values have been added to the ifType column in the ifTable object:
In MIB-I, this group contained a table which permitted mappings from network addresses (e.g., IP addresses) to physical addresses (e.g., MAC addresses). Experience has shown that efficient implementations of this table make two assumptions: a single network protocol environment, and mappings occur only from network address to physical address.
The need to support multi-protocol nodes (e.g., those with both the IP and CLNP active), and the need to support the inverse mapping (e.g., for ES-IS), have invalidated both of these assumptions. As such, the atTable object is declared deprecated.
In order to meet both the multi-protocol and inverse mapping requirements, MIB-II and its successors will allocate up to two address translation tables inside each network protocol group. That is, the IP group will contain one address translation table, for going from IP addresses to physical addresses. Similarly, when a document defining MIB objects for the CLNP is produced (e.g., [8]), it will contain two tables, for mappings in both directions, as this is required for full functionality.
It should be noted that the choice of two tables (one for each direction of mapping) provides for ease of implementation in many cases, and does not introduce undue burden on implementations which realize the address translation abstraction through a single internal table.
The access attribute of the variable ipForwarding has been changed from read-only to read-write.
In addition, there is a new column to the ipAddrTable object,
ipAdEntReasmMaxSize
which keeps track of the largest IP datagram that can be re- assembled on a particular interface. There is also a new column in the ipRoutingTable object,
ipRouteMask
which is used for IP routing subsystems that support arbitrary subnet masks.
One new object is added to the IP group:
ipNetToMediaTable
which is the address translation table for the IP group (providing identical functionality to the now deprecated atTable in the address translation group).
Experience has indicated a need for additional objects that are useful in EGP monitoring. In addition to making several additions to the egpNeighborTable object, a new variable is added:
egpAs
which gives the autonomous system associated with this EGP entity.
MIB-I was lacking in that it did not distinguish between different types of transmission media. A new group, the Transmission group, is allocated for this purpose:
transmission OBJECT IDENTIFIER ::= { mib-2 10 }
When Internet-standard definitions for managing transmission media are defined, the transmission group is used to provide a prefix for the names of those objects.
Typically, such definitions reside in the experimental portion of the MIB until they are "proven", then as a part of the Internet standardization process, the definitions are accordingly elevated and a new object identifier, under the transmission group is defined. By convention, the name assigned is:
type OBJECT IDENTIFIER ::= { transmission number }
where "type" is the symbolic value used for the media in the ifType column of the ifTable object, and "number" is the actual integer value corresponding to the symbol.
The application-oriented working groups of the IETF have been tasked to be receptive towards defining MIB variables specific to their respective applications.
For the SNMP, it is useful to have statistical information. A new group, the SNMP group, is allocated for this purpose:
Managed objects are accessed via a virtual information store, termed
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the Management Information Base or MIB. Objects in the MIB are defined using Abstract Syntax Notation One (ASN.1) [9].
The mechanisms used for describing these objects are specified the companion memo, 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 companion memo 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 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. This memo specifies the use of the basic encoding rules (BER) of ASN.1 [10], subject to the additional requirements imposed by the SNMP [14].
Since this list of managed objects contains only the essential elements, there is no need to allow individual objects to be optional. Rather, the objects are arranged into the following groups:
There are two reasons for defining these groups: to provide a means of assigning object identifiers; and, to provide a method for implementations of managed agents to know which objects they must implement. This method is as follows: if the semantics of a group is applicable to an implementation, then it must implement all objects
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in that group. For example, an implementation must implement the EGP group if and only if it implements the EGP.
The next section contains the specification of all object types contained in the MIB. Following the conventions of the companion memo, the object types are defined using the following fields:
OBJECT: ------- A textual name, termed the OBJECT DESCRIPTOR, for the object type, along with its corresponding OBJECT IDENTIFIER.
Syntax: The abstract syntax for the object type, presented using ASN.1. This must resolve to an instance of the ASN.1 type ObjectSyntax defined in the SMI.
Definition: A textual description of the semantics of the object type. Implementations should ensure that their interpretation of the object type fulfills this definition since this MIB is intended for use in multi- vendor environments. As such it is vital that object types have consistent meaning across all machines.
Access: A keyword, one of read-only, read-write, write-only, or not-accessible. Note that this designation specifies the minimum level of support required. As a local matter, implementations may support other access types (e.g., an implementation may elect to permitting writing a variable marked herein as read-only). Further, protocol-specific "views" (e.g., those implied by an SNMP community) may make further restrictions on access to a variable.
Status: A keyword, one of mandatory, optional, obsolete, or deprecated. Use of deprecated implies mandatory status.
Implementation of the System group is mandatory for all systems.
OBJECT: ------- sysDescr { system 1 }
Syntax: DisplayString (SIZE (0..255))
Definition: A textual description of the entity. This value should include the full name and version identification of the system's hardware type, software operating-system, and networking software. It is mandatory that this only contain printable ASCII characters.
Access: read-only.
Status: mandatory.
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OBJECT: ------- sysObjectID { system 2 }
Syntax: OBJECT IDENTIFIER
Definition: The vendor's authoritative identification of the network management subsystem contained in the entity. This value is allocated within the SMI enterprises subtree (1.3.6.1.4.1) and provides an easy and unambiguous means for determining "what kind of box" is being managed. For example, if vendor "Flintstones, Inc." was assigned the subtree 1.3.6.1.4.1.4242, it could assign the identifier 1.3.6.1.4.1.4242.1.1 to its "Fred Router".
Access: read-only.
Status: mandatory.
OBJECT: ------- sysUpTime { system 3 }
Syntax: TimeTicks
Definition: The time (in hundredths of a second) since the network management portion of the system was last re-initialized.
Access: read-only.
Status: mandatory.
OBJECT: ------- sysContact { system 4 }
Syntax: DisplayString (SIZE (0..255))
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Definition: The textual identification of the contact person for this managed node, together with information on how to contact this person.
Access: read-write.
Status: mandatory.
OBJECT: ------- sysName { system 5 }
Syntax: DisplayString (SIZE (0..255))
Definition: An administratively-assigned name for this managed node. By convention, this is the node's fully-qualified domain name.
Access: read-write.
Status: mandatory.
OBJECT: ------- sysLocation { system 6 }
Syntax: DisplayString (SIZE (0..255))
Definition: The physical location of this node (e.g., "telephone closet, 3rd floor").
Access: read-only.
Status: mandatory.
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OBJECT: ------- sysServices { system 7 }
Syntax: INTEGER (0..127)
Definition: A value which indicates the set of services that this entity potentially offers. The value is a sum. This sum initially takes the value zero, Then, for each layer, L, in the range 1 through 7, that this node performs transactions for, 2 raised to (L - 1) is added to the sum. For example, a node which performs only routing functions would have a value of 4 (2^(3-1)). In contrast, a node which is a host offering application services would have a value of 72 (2^(4-1) + 2^(7-1)). Note that in the context of the Internet suite of protocols, values should be calculated accordingly:
layer functionality 1 physical (e.g., repeaters) 2 datalink/subnetwork (e.g., bridges) 3 internet (e.g., supports the IP) 4 end-to-end (e.g., supports the TCP) 7 applications (e.g., supports the SMTP)
For systems including OSI protocols, layers 5 and 6 may also be counted.
The Interfaces table contains information on the entity's interfaces. Each interface is thought of as being attached to a "subnetwork". Note that this term should not be confused with "subnet" which refers to an addressing partitioning scheme used in the Internet suite of protocols.
OBJECT: ------- ifTable { interfaces 2 }
Syntax: SEQUENCE OF IfEntry
Definition: A list of interface entries. The number of entries is given by the value of ifNumber.
Definition: An interface entry containing objects at the subnetwork layer and below for a particular interface.
Access: read-only.
Status: mandatory.
We now consider the individual components of each interface entry:
OBJECT: ------- ifIndex { ifEntry 1 }
Syntax: INTEGER
Definition: A unique value for each interface. Its value ranges between 1 and the value of ifNumber. The value for each interface must remain constant at least from one re- initialization of the entity's network management system to the next re-initialization.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifDescr { ifEntry 2 }
Syntax: DisplayString (SIZE (0..255))
Definition: 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 hardware interface.
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Access: read-only.
Status: mandatory.
OBJECT: ------- ifType { ifEntry 3 }
Syntax: INTEGER { other(1), -- none of the following regular1822(2), hdh1822(3), ddn-x25(4), rfc877-x25(5), ethernet-csmacd(6), iso88023-csmacd(7), iso88024-tokenBus(8), iso88025-tokenRing(9), iso88026-man(10), starLan(11), proteon-10Mbit(12), proteon-80Mbit(13), hyperchannel(14), fddi(15), lapb(16), sdlc(17), t1-carrier(18), cept(19), -- european equivalent of T-1 basicISDN(20), primaryISDN(21), -- proprietary serial propPointToPointSerial(22), ppp(23), softwareLoopback(24), eon(25), -- CLNP over IP [12] ethernet-3Mbit(26) nsip(27), -- XNS over IP slip(28) -- generic SLIP }
Definition: The type of interface, distinguished according to the physical/link protocol(s) immediately "below" the network layer in the protocol stack.
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Access: read-only.
Status: mandatory.
OBJECT: ------- ifMtu { ifEntry 4 }
Syntax: INTEGER
Definition: The size of the largest datagram 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.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifSpeed { ifEntry 5 }
Syntax: Gauge
Definition: 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.
Access: read-only.
Status: mandatory.
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OBJECT: ------- ifPhysAddress { ifEntry 6 }
Syntax: OCTET STRING
Definition: The interface's address at the protocol layer immediately "below" the network layer in the protocol stack. For interfaces which do not have such an address (e.g., a serial line), this object should contain an octet string of zero length.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifAdminStatus { ifEntry 7 }
Syntax: INTEGER { up(1), -- ready to pass packets down(2), testing(3) -- in some test mode }
Definition: The desired state of the interface. The testing(3) state indicates that no operational packets can be passed.
Access: read-write.
Status: mandatory.
OBJECT: ------- ifOperStatus { ifEntry 8 }
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Syntax: INTEGER { up(1), -- ready to pass packets down(2), testing(3) -- in some test mode }
Definition: The current operational state of the interface. The testing(3) state indicates that no operational packets can be passed.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifLastChange { ifEntry 9 }
Syntax: TimeTicks
Definition: 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.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifInOctets { ifEntry 10 }
Syntax: Counter
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Definition: The total number of octets received on the interface, including framing characters.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifInUcastPkts { ifEntry 11 }
Syntax: Counter
Definition: The number of subnetwork-unicast packets delivered to a higher-layer protocol.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifInNUcastPkts { ifEntry 12 }
Syntax: Counter
Definition: The number of non-unicast (i.e., subnetwork-broadcast or subnetwork-multicast) packets delivered to a higher-layer protocol.
Access: read-only.
Status: mandatory.
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OBJECT: ------- ifInDiscards { ifEntry 13 }
Syntax: Counter
Definition: 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.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifInErrors { ifEntry 14 }
Syntax: Counter
Definition: The number of inbound packets that contained errors preventing them from being deliverable to a higher-layer protocol.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifInUnknownProtos { ifEntry 15 }
Syntax: Counter
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Definition: The number of packets received via the interface which were discarded because of an unknown or unsupported protocol.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifOutOctets { ifEntry 16 }
Syntax: Counter
Definition: The total number of octets transmitted out of the interface, including framing characters.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifOutUcastPkts { ifEntry 17 }
Syntax: Counter
Definition: The total number of packets that higher-level protocols requested be transmitted to a subnetwork-unicast address, including those that were discarded or not sent.
Access: read-only.
Status: mandatory.
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OBJECT: ------- ifOutNUcastPkts { ifEntry 18 }
Syntax: Counter
Definition: The total number of packets that higher-level protocols requested be transmitted to a non-unicast (i.e., a subnetwork-broadcast or subnetwork-multicast) address, including those that were discarded or not sent.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifOutDiscards { ifEntry 19 }
Syntax: Counter
Definition: 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.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifOutErrors { ifEntry 20 }
Syntax: Counter
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Definition: The number of outbound packets that could not be transmitted because of errors.
Access: read-only.
Status: mandatory.
OBJECT: ------- ifOutQLen { ifEntry 21 }
Syntax: Gauge
Definition: The length of the output packet queue (in packets).
Access: read-only.
Status: mandatory.
OBJECT: ------- ifSpecific { ifEntry 22 }
Syntax: OBJECT IDENTIFIER
Definition: A reference to MIB definitions specific to the particular media being used to realize the interface. For example, if the interface is realized by an ethernet, then the value of this object refers to a document defining objects specific to ethernet. If an agent is not configured to have a value for any of these variables, the object identifier
nullSpecific OBJECT IDENTIFIER ::= { 0 0 }
is returned. Note that "nullSpecific" is a syntatically valid object identifier, and any conformant
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implementation of ASN.1 and BER must be able to generate and recognize this value.
Implementation of the Address Translation group is mandatory for all systems. Note however that this group is deprecated by MIB-II. That is, it is being included solely for compatibility with MIB-I nodes, and will most likely be excluded from MIB-III nodes. From MIB-II and onwards, each network protocol group contains its own address translation tables.
The Address Translation group contains one table which is the union across all interfaces of the translation tables for converting a NetworkAddress (e.g., an IP address) into a subnetwork-specific address. For lack of a better term, this document refers to such a subnetwork-specific address as a "physical" address.
Examples of such translation tables are: for broadcast media where ARP is in use, the translation table is equivalent to the ARP cache; or, on an X.25 network where non-algorithmic translation to X.121 addresses is required, the translation table contains the NetworkAddress to X.121 address equivalences.
OBJECT: ------- atTable { at 1 }
Syntax: SEQUENCE OF AtEntry
Definition: The Address Translation tables contain the NetworkAddress to "physical" address equivalences. Some interfaces do not use translation tables for determining address equivalences (e.g., DDN-X.25 has an algorithmic method); if all interfaces are of this type, then the Address Translation table is empty, i.e., has zero entries.
Definition: Each entry contains one NetworkAddress to "physical" address equivalence.
Access: read-write.
Status: deprecated.
We now consider the individual components of each Address Translation table entry:
OBJECT: ------- atIfIndex { atEntry 1 }
Syntax: INTEGER
Definition: The interface on which this entry's equivalence is effective. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex.
Access: read-write.
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Status: deprecated.
OBJECT: ------- atPhysAddress { atEntry 2 }
Syntax: OCTET STRING
Definition: The media-dependent "physical" address.
Setting this object to a null string (one of zero length) has the effect of invaliding the corresponding entry in the atTable object. That is, it effectively disassociates the interface identified with said entry from 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 not currently in use. Proper interpretation of such entries requires examination of the relevant atPhysAddress object.
Access: read-write.
Status: deprecated.
OBJECT: ------- atNetAddress { atEntry 3 }
Syntax: NetworkAddress
Definition: The NetworkAddress (e.g., the IP address) corresponding to the media-dependent "physical" address.
Implementation of the IP group is mandatory for all systems.
OBJECT: ------- ipForwarding { ip 1 }
Syntax: INTEGER { forwarding(1), -- i.e., acting as a gateway not-forwarding(2) -- i.e., NOT acting as a gateway }
Definition: The indication of whether this entity is acting as an IP gateway in respect to the forwarding of datagrams received by, but not addressed to, this entity. IP gateways forward datagrams. IP hosts do not (except those source-routed via the host).
Access: read-write.
Status: mandatory.
OBJECT: ------- ipDefaultTTL { ip 2 }
Syntax: INTEGER
Definition: The default value inserted into the Time-To-Live field of the IP header of datagrams originated at this entity, whenever a TTL value is not supplied by the transport layer protocol.
Access: read-write.
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Status: mandatory.
OBJECT: ------- ipInReceives { ip 3 }
Syntax: Counter
Definition: The total number of input datagrams received from interfaces, including those received in error.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipInHdrErrors { ip 4 }
Syntax: Counter
Definition: The number of input datagrams discarded due to errors in their IP headers, including bad checksums, version number mismatch, other format errors, time-to-live exceeded, errors discovered in processing their IP options, etc.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipInAddrErrors { ip 5 }
Syntax: Counter
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Definition: The number of input datagrams discarded because the IP address in their IP header's destination field was not a valid address to be received at this entity. This count includes invalid addresses (e.g., 0.0.0.0) and addresses of unsupported Classes (e.g., Class E). For entities which are not IP Gateways and therefore do not forward datagrams, this counter includes datagrams discarded because the destination address was not a local address.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipForwDatagrams { ip 6 }
Syntax: Counter
Definition: The number of input datagrams for which this entity was not their final IP destination, as a result of which an attempt was made to find a route to forward them to that final destination. In entities which do not act as IP Gateways, this counter will include only those packets which were Source-Routed via this entity, and the Source-Route option processing was successful.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipInUnknownProtos { ip 7 }
Syntax: Counter
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Definition: The number of locally-addressed datagrams received successfully but discarded because of an unknown or unsupported protocol.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipInDiscards { ip 8 }
Syntax: Counter
Definition: The number of input IP datagrams for which no problems were encountered to prevent their continued processing, but which were discarded (e.g., for lack of buffer space). Note that this counter does not include any datagrams discarded while awaiting re-assembly.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipInDelivers { ip 9 }
Syntax: Counter
Definition: The total number of input datagrams successfully delivered to IP user-protocols (including ICMP).
Access: read-only.
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Status: mandatory.
OBJECT: ------- ipOutRequests { ip 10 }
Syntax: Counter
Definition: The total number of IP datagrams which local IP user- protocols (including ICMP) supplied to IP in requests for transmission. Note that this counter does not include any datagrams counted in ipForwDatagrams.
Access: read-only.
Status: mandatory.
OBJECT: ipOutDiscards { ip 11 }
Syntax: Counter
Definition: The number of output IP datagrams for which no problem was encountered to prevent their transmission to their destination, but which were discarded (e.g., for lack of buffer space). Note that this counter would include datagrams counted in ipForwDatagrams if any such packets met this (discretionary) discard criterion.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipOutNoRoutes { ip 12 }
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Syntax: Counter
Definition: The number of IP datagrams discarded because no route could be found to transmit them to their destination. Note that this counter includes any packets counted in ipForwDatagrams which meet this "no-route" criterion. Note that this includes any datagarms which a host cannot route because all of its default gateways are down.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipReasmTimeout { ip 13 }
Syntax: INTEGER
Definition: The maximum number of seconds which received fragments are held while they are awaiting reassembly at this entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipReasmReqds { ip 14 }
Syntax: Counter
Definition: The number of IP fragments received which needed to be reassembled at this entity.
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Access: read-only.
Status: mandatory.
OBJECT: ------- ipReasmOKs { ip 15 }
Syntax: Counter
Definition: The number of IP datagrams successfully re-assembled.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipReasmFails { ip 16 }
Syntax: Counter
Definition: The number of failures detected by the IP re-assembly algorithm (for whatever reason: timed out, errors, etc). Note that this is not necessarily a count of discarded IP fragments since some algorithms (notably the algorithm in RFC 815) can lose track of the number of fragments by combining them as they are received.
Access: read-only.
Status: mandatory.
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OBJECT: ------- ipFragOKs { ip 17 }
Syntax: Counter
Definition: The number of IP datagrams that have been successfully fragmented at this entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipFragFails { ip 18 }
Syntax: Counter
Definition: The number of IP datagrams that have been discarded because they needed to be fragmented at this entity but could not be, e.g., because their "Don't Fragment" flag was set.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipFragCreates { ip 19 }
Syntax: Counter
Definition: The number of IP datagram fragments that have been generated as a result of fragmentation at this entity.
Definition: The addressing information for one of this entity's IP addresses.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipAdEntAddr { ipAddrEntry 1 }
Syntax: IpAddress
Definition: The IP address to which this entry's addressing information pertains.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipAdEntIfIndex { ipAddrEntry 2 }
Syntax: INTEGER
Definition: The index value which uniquely identifies the interface to which this entry is applicable. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex.
Access: read-only.
Status: mandatory.
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OBJECT: ------- ipAdEntNetMask { ipAddrEntry 3 }
Syntax: IpAddress
Definition: The subnet mask associated with the IP address of this entry. The value of the mask is an IP address with all the network bits set to 1 and all the hosts bits set to 0.
Definition: The value of the least-significant bit in the IP broadcast address used for sending datagrams on the (logical) interface associated with the IP address of this entry. For example, when the Internet standard all-ones broadcast address is used, the value will be 1. This value applies to both the subnet and network broadcasts addresses used by the entity on this (logical) interface.
We now consider the individual components of each route in the IP Routing table:
OBJECT: ------- ipRouteDest { ipRouteEntry 1 }
Syntax: IpAddress
Definition: The destination IP address of this route. An entry with a value of 0.0.0.0 is considered a default route. Multiple routes to a single destination can appear in the table, but access to such multiple entries is dependent on the table-access mechanisms defined by the network management protocol in use.
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Access: read-write.
Status: mandatory.
OBJECT: ------- ipRouteIfIndex { ipRouteEntry 2 }
Syntax: INTEGER
Definition: The index value which uniquely identifies the local interface through which the next hop of this route should be reached. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex.
Access: read-write.
Status: mandatory.
OBJECT: ------- ipRouteMetric1 { ipRouteEntry 3 }
Syntax: INTEGER
Definition: The primary routing metric for this route. The semantics of this metric are determined by the routing-protocol specified in the route's ipRouteProto value. If this metric is not used, its value should be set to -1.
Access: read-write.
Status: mandatory.
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OBJECT: ------- ipRouteMetric2 { ipRouteEntry 4 }
Syntax: INTEGER
Definition: An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipRouteProto value. If this metric is not used, its value should be set to -1.
Access: read-write.
Status: mandatory.
OBJECT: ------- ipRouteMetric3 { ipRouteEntry 5 }
Syntax: INTEGER
Definition: An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipRouteProto value. If this metric is not used, its value should be set to -1.
Access: read-write.
Status: mandatory.
OBJECT: ------- ipRouteMetric4 { ipRouteEntry 6 }
Syntax: INTEGER
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Definition: An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipRouteProto value. If this metric is not used, its value should be set to -1.
Access: read-write.
Status: mandatory.
OBJECT: ------- ipRouteNextHop { ipRouteEntry 7 }
Syntax: IpAddress
Definition: The IP address of the next hop of this route. (In the case of a route bound to an interface which is realized via a broadcast media, the value of this field is the agent's IP address on that interface.)
Access: read-write.
Status: mandatory.
OBJECT: ------- ipRouteType { ipRouteEntry 8 }
Syntax: INTEGER { other(1), -- none of the following
invalid(2), -- an invalidated route
-- route to directly direct(3), -- connected (sub-)network
-- route to a non-local remote(4) -- host/network/sub-network
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}
Definition: The type of route.
Setting this object to the value invalid(2) has the effect of invalidating the corresponding entry in the ipRoutingTable object. That is, it effectively disassociates the destination identified with said entry from the route 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 not currently in use. Proper interpretation of such entries requires examination of the relevant ipRouteType object.
Access: read-write.
Status: mandatory.
OBJECT: ------- ipRouteProto { ipRouteEntry 9 }
Syntax: INTEGER { other(1), -- none of the following
Definition: The routing mechanism via which this route was learned. Inclusion of values for gateway routing protocols is not intended to imply that hosts should support those protocols.
Access: read-only.
Status: mandatory.
OBJECT: ------- ipRouteAge { ipRouteEntry 10 }
Syntax: INTEGER
Definition: The number of seconds since this route was last updated or otherwise determined to be correct. Note that no semantics of "too old" can be implied except through knowledge of the routing protocol by which the route was learned.
Access: read-write.
Status: mandatory.
OBJECT: ------- ipRouteMask { ipRouteEntry 11 }
Syntax: IpAddress
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Definition: Indicate the mask to be logical-ANDed with the destination address before being compared to the value in the ipRouteDest field. For those systems that do not support arbitrary subnet masks, an agent constructs the value of the ipRouteMask by determining whether the value of the correspondent ipRouteDest field belong to a class-A, B, or C network, and then using one of:
If the value of the ipRouteDest is 0.0.0.0 (a default route), then the mask value is also 0.0.0.0. It should be noted that all IP routing subsystems implicitly use this mechanism.
The Address Translation tables contain the IpAddress to "physical" address equivalences. Some interfaces do not use translation tables for determining address equivalences (e.g., DDN-X.25 has an algorithmic method); if all interfaces are of this type, then the Address Translation table is empty, i.e., has zero entries.
OBJECT: ------- ipNetToMediaTable { ip 22 }
Syntax: SEQUENCE OF IpNetToMediaEntry
Definition: The IP Address Translation table used for mapping from IP addresses to physical addresses.
Definition: The interface on which this entry's equivalence is effective. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex.
Setting this object to the value invalid(2) has the effect of invalidating the corresponding entry in the ipNetToMediaTable. That is, it effectively disassociates the interface identified with said entry from 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 not currently in use. Proper interpretation of such entries requires examination of the relevant ipNetToMediaType object.
Implementation of the ICMP group is mandatory for all systems.
The ICMP group contains the ICMP input and output statistics.
OBJECT: ------- icmpInMsgs { icmp 1 }
Syntax: Counter
Definition: The total number of ICMP messages which the entity received. Note that this counter includes all those counted by icmpInErrors.
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Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInErrors { icmp 2 }
Syntax: Counter
Definition: The number of ICMP messages which the entity received but determined as having ICMP-specific errors (bad ICMP checksums, bad length, etc.).
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInDestUnreachs { icmp 3 }
Syntax: Counter
Definition: The number of ICMP Destination Unreachable messages received.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInTimeExcds { icmp 4 }
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Syntax: Counter
Definition: The number of ICMP Time Exceeded messages received.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInParmProbs { icmp 5 }
Syntax: Counter
Definition: The number of ICMP Parameter Problem messages received.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInSrcQuenchs { icmp 6 }
Syntax: Counter
Definition: The number of ICMP Source Quench messages received.
Access: read-only.
Status: mandatory.
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OBJECT: ------- icmpInRedirects { icmp 7 }
Syntax: Counter
Definition: The number of ICMP Redirect messages received.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInEchos { icmp 8 }
Syntax: Counter
Definition: The number of ICMP Echo (request) messages received.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInEchoReps { icmp 9 }
Syntax: Counter
Definition: The number of ICMP Echo Reply messages received.
Access: read-only.
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Status: mandatory.
OBJECT: ------- icmpInTimestamps { icmp 10 }
Syntax: Counter
Definition: The number of ICMP Timestamp (request) messages received.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInTimestampReps { icmp 11 }
Syntax: Counter
Definition: The number of ICMP Timestamp Reply messages received.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInAddrMasks { icmp 12 }
Syntax: Counter
Definition: The number of ICMP Address Mask Request messages received.
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Access: read-only.
Status: mandatory.
OBJECT: ------- icmpInAddrMaskReps { icmp 13 }
Syntax: Counter
Definition: The number of ICMP Address Mask Reply messages received.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutMsgs { icmp 14 }
Syntax: Counter
Definition: The total number of ICMP messages which this entity attempted to send. Note that this counter includes all those counted by icmpOutErrors.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutErrors { icmp 15 }
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Syntax: Counter
Definition: The number of ICMP messages which this entity did not send due to problems discovered within ICMP such as a lack of buffers. This value should not include errors discovered outside the ICMP layer such as the inability of IP to route the resultant datagram. In some implementations there may be no types of error which contribute to this counter's value.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutDestUnreachs { icmp 16 }
Syntax: Counter
Definition: The number of ICMP Destination Unreachable messages sent.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutTimeExcds { icmp 17 }
Syntax: Counter
Definition: The number of ICMP Time Exceeded messages sent.
Access: read-only.
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Status: mandatory.
OBJECT: ------- icmpOutParmProbs { icmp 18 }
Syntax: Counter
Definition: The number of ICMP Parameter Problem messages sent.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutSrcQuenchs { icmp 19 }
Syntax: Counter
Definition: The number of ICMP Source Quench messages sent.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutRedirects { icmp 20 }
Syntax: Counter
Definition: The number of ICMP Redirect messages sent. For a host, this object will always be zero, since hosts do not send
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redirects.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutEchos { icmp 21 }
Syntax: Counter
Definition: The number of ICMP Echo (request) messages sent.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutEchoReps { icmp 22 }
Syntax: Counter
Definition: The number of ICMP Echo Reply messages sent.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutTimestamps { icmp 23 }
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Syntax: Counter
Definition: The number of ICMP Timestamp (request) messages sent.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutTimestampReps { icmp 24 }
Syntax: Counter
Definition: The number of ICMP Timestamp Reply messages sent.
Access: read-only.
Status: mandatory.
OBJECT: ------- icmpOutAddrMasks { icmp 25 }
Syntax: Counter
Definition: The number of ICMP Address Mask Request messages sent.
Access: read-only.
Status: mandatory.
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OBJECT: ------- icmpOutAddrMaskReps { icmp 26 }
Syntax: Counter
Definition: The number of ICMP Address Mask Reply messages sent.
Implementation of the TCP group is mandatory for all systems that implement the TCP.
Note that instances of object types that represent information about a particular TCP connection are transient; they persist only as long as the connection in question.
OBJECT: ------- tcpRtoAlgorithm { tcp 1 }
Syntax: INTEGER { other(1), -- none of the following constant(2), -- a constant rto rsre(3), -- MIL-STD-1778, Appendix B vanj(4) -- Van Jacobson's algorithm [11] }
Definition: The algorithm used to determine the timeout value used for retransmitting unacknowledged octets.
Access: read-only.
Status: mandatory.
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OBJECT: ------- tcpRtoMin { tcp 2 }
Syntax: INTEGER
Definition: The minimum value permitted by a TCP implementation for the retransmission timeout, measured in milliseconds. More refined semantics for objects of this type depend upon the algorithm used to determine the retransmission timeout. In particular, when the timeout algorithm is rsre(3), an object of this type has the semantics of the LBOUND quantity described in RFC 793.
Access: read-only.
Status: mandatory.
OBJECT: ------- tcpRtoMax { tcp 3 }
Syntax: INTEGER
Definition: The maximum value permitted by a TCP implementation for the retransmission timeout, measured in milliseconds. More refined semantics for objects of this type depend upon the algorithm used to determine the retransmission timeout. In particular, when the timeout algorithm is rsre(3), an object of this type has the semantics of the UBOUND quantity described in RFC 793.
Access: read-only.
Status: mandatory.
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OBJECT: ------- tcpMaxConn { tcp 4 }
Syntax: INTEGER
Definition: The limit on the total number of TCP connections the entity can support. In entities where the maximum number of connections is dynamic, this object should contain the value "-1".
Access: read-only.
Status: mandatory.
OBJECT: ------- tcpActiveOpens { tcp 5 }
Syntax: Counter
Definition: The number of times TCP connections have made a direct transition to the SYN-SENT state from the CLOSED state.
Access: read-only.
Status: mandatory.
OBJECT: ------- tcpPassiveOpens { tcp 6 }
Syntax: Counter
Definition: The number of times TCP connections have made a direct transition to the SYN-RCVD state from the LISTEN state.
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Access: read-only.
Status: mandatory.
OBJECT: ------- tcpAttemptFails { tcp 7 }
Syntax: Counter
Definition: The number of times TCP connections have made a direct transition to the CLOSED state from either the SYN-SENT state or the SYN-RCVD state, plus the number of times TCP connections have made a direct transition to the LISTEN state from the SYN-RCVD state.
Access: read-only.
Status: mandatory.
OBJECT: ------- tcpEstabResets { tcp 8 }
Syntax: Counter
Definition: The number of times TCP connections have made a direct transition to the CLOSED state from either the ESTABLISHED state or the CLOSE-WAIT state.
Access: read-only.
Status: mandatory.
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OBJECT: ------- tcpCurrEstab { tcp 9 }
Syntax: Gauge
Definition: The number of TCP connections for which the current state is either ESTABLISHED or CLOSE-WAIT.
Access: read-only.
Status: mandatory.
OBJECT: ------- tcpInSegs { tcp 10 }
Syntax: Counter
Definition: The total number of segments received, including those received in error. This count includes segments received on currently established connections.
Access: read-only.
Status: mandatory.
OBJECT: ------- tcpOutSegs { tcp 11 }
Syntax: Counter
Definition: The total number of segments sent, including those on current connections but excluding those containing only retransmitted octets.
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Access: read-only.
Status: mandatory.
OBJECT: ------- tcpRetransSegs { tcp 12 }
Syntax: Counter
Definition: The total number of segments retransmitted - that is, the number of TCP segments transmitted containing one or more previously transmitted octets.
Definition: Information about a particular current TCP connection. An object of this type is transient, in that it ceases to exist when (or soon after) the connection makes the transition to the CLOSED state.
Definition: The local IP address for this TCP connection. In the case of a connection in the listen state which is willing to accept connections for any IP interface associated with the node, the value 0.0.0.0 is used.
Implementation of the UDP group is mandatory for all systems which implement the UDP.
OBJECT: ------- udpInDatagrams { udp 1 }
Syntax: Counter
Definition: The total number of UDP datagrams delivered to UDP users.
Access: read-only.
Status: mandatory.
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OBJECT: ------- udpNoPorts { udp 2 }
Syntax: Counter
Definition: The total number of received UDP datagrams for which there was no application at the destination port.
Access: read-only.
Status: mandatory.
OBJECT: ------- udpInErrors { udp 3 }
Syntax: Counter
Definition: The number of received UDP datagrams that could not be delivered for reasons other than the lack of an application at the destination port.
Access: read-only.
Status: mandatory.
OBJECT: ------- udpOutDatagrams { udp 4 }
Syntax: Counter
Definition: The total number of UDP datagrams sent from this entity.
Definition: Information about a particular current UDP listener.
Access: read-only.
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Status: mandatory.
OBJECT: ------- udpLocalAddress { udpEntry 1 }
Syntax: IpAddress
Definition: The local IP address for this UDP listener. In the case of a UDP listener which is willing to accept datagrams for any IP interface associated with the node, the value 0.0.0.0 is used.
Access: read-only.
Status: mandatory.
OBJECT: ------- udpLocalPort { udpEntry 2 }
Syntax: INTEGER (0..65535)
Definition: The local port number for this UDP listener.
Definition: The EGP state of the local system with respect to this entry's EGP neighbor. Each EGP state is represented by a value that is one greater than the numerical value associated with said state in RFC 904.
Access: read-only.
Status: mandatory.
OBJECT: ------- egpNeighAddr { egpNeighEntry 2 }
Syntax: IpAddress
Definition: The IP address of this entry's EGP neighbor.
Access: read-only.
Status: mandatory.
OBJECT: ------- egpNeighAs { egpNeighEntry 3 }
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Syntax: INTEGER
Definition: The autonomous system of this EGP peer. Zero should be specified if the autonomous system number of the neighbor is not yet known.
Definition: A control variable used to trigger operator-initiated Start and Stop events. When read, this variable always returns the most recent value that egpNeightEventTrigger was set to. If it has not been set since the last initialization of the network management subsystem on the node, it returns a value of "stop".
Based on the transmission media underlying each interface on a system, the corresponding portion of the Transmission group is mandatory for that system.
When Internet-standard definitions for managing transmission media are defined, the transmission group is used to provide a prefix for the names of those objects.
Typically, such definitions reside in the experimental portion of the MIB until they are "proven", then as a part of the Internet standardization process, the definitions are accordingly elevated and a new object identifier, under the transmission group is defined. By convention, the name assigned is:
type OBJECT IDENTIFIER ::= { transmission number }
where "type" is the symbolic value used for the media in the ifType column of the ifTable object, and "number" is the actual integer value corresponding to the symbol.
Implementation of the SNMP group is mandatory for all systems which support an SNMP protocol entity. Some of the objects defined below
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will be zero-valued in those SNMP implementations that are optimized to support only those functions specific to either a management agent or a management client.
OBJECT: ------- snmpInPkts { snmp 1 }
Syntax: Counter
Definition: The total number of PDUs delivered to the SNMP entity from the transport service.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutPkts { snmp 2 }
Syntax: Counter
Definition: The total number of SNMP PDUs which were passed from the SNMP protocol entity to the transport service.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInBadVersions { snmp 3 }
Syntax: Counter
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Definition: The total number of syntactically correct SNMP PDUs which were delivered to the SNMP protocol entity and were for an unsupported SNMP version.
Definition: The total number of SNMP PDUs delivered to the SNMP protocol entity which used a SNMP community name not known to said entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInBadCommunityUses { snmp 5 }
Syntax: Counter
Definition: The total number of SNMP PDUs delivered to the SNMP protocol entity which represented an SNMP operation which was not allowed by the SNMP community named in the PDU.
Access: read-only.
Status: mandatory.
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OBJECT: ------- snmpInASNParseErrs { snmp 6 }
Syntax: Counter
Definition: The total number of ASN.1 parsing errors (either in encoding or syntax) encountered by the SNMP protocol entity when decoding received SNMP PDUs.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInBadTypes { snmp 7 }
Syntax: Counter
Definition: The total number of SNMP PDUs delivered to the SNMP protocol entity which had an unknown PDU type.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInTooBigs { snmp 8 }
Syntax: Counter
Definition: The total number valid SNMP PDUs which were delivered to the SNMP protocol entity and for which the value of the "ErrorStatus" component is "tooBig."
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Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInNoSuchNames { snmp 9 }
Syntax: Counter
Definition: The total number valid SNMP PDUs which were delivered to the SNMP protocol entity and for which the value of the "ErrorStatus" component is "noSuchName."
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInBadValues { snmp 10 }
Syntax: Counter
Definition: The total number valid SNMP PDUs which were delivered to the SNMP protocol entity and for which the value of the "ErrorStatus" component is "badValue."
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInReadOnlys { snmp 11 }
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Syntax: Counter
Definition: The total number valid SNMP PDUs which were delivered to the SNMP protocol entity and for which the value of the "ErrorStatus" component is "readOnly."
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInGenErrs { snmp 12 }
Syntax: Counter
Definition: The total number valid SNMP PDUs which were delivered to the SNMP protocol entity and for which the value of the "ErrorStatus" component is "genErr."
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInTotalReqVars { snmp 13 }
Syntax: Counter
Definition: The total number of MIB objects which have been retrieved successfully by the SNMP protocol entity as the result of receiving valid SNMP Get-Request and Get-Next PDUs.
Access: read-only.
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Status: mandatory.
OBJECT: ------- snmpInTotalSetVars { snmp 14 }
Syntax: Counter
Definition: The total number of MIB objects which have been altered successfully by the SNMP protocol entity as the result of receiving valid SNMP Set-Request PDUs.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInGetRequests { snmp 15 }
Syntax: Counter
Definition: The total number of SNMP Get-Request PDUs which have been accepted and processed by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInGetNexts { snmp 16 }
Syntax: Counter
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Definition: The total number of SNMP Get-Next PDUs which have been accepted and processed by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInSetRequests { snmp 17 }
Syntax: Counter
Definition: The total number of SNMP Set-Request PDUs which have been accepted and processed by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpInGetResponses { snmp 18 }
Syntax: Counter
Definition: The total number of SNMP Get-Response PDUs which have been accepted and processed by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
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OBJECT: ------- snmpInTraps { snmp 19 }
Syntax: Counter
Definition: The total number of SNMP Trap PDUs which have been accepted and processed by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutTooBigs { snmp 20 }
Syntax: Counter
Definition: The total number valid SNMP PDUs which were generated by the SNMP protocol entity and for which the value of the "ErrorStatus" component is "tooBig."
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutNoSuchNames { snmp 21 }
Syntax: Counter
Definition: The total number valid SNMP PDUs which were generated by the SNMP protocol entity and for which the value of the "ErrorStatus" component is "noSuchName."
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Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutBadValues { snmp 22 }
Syntax: Counter
Definition: The total number valid SNMP PDUs which were generated by the SNMP protocol entity and for which the value of the "ErrorStatus" component is "badValue."
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutReadOnlys { snmp 23 }
Syntax: Counter
Definition: The total number valid SNMP PDUs which were generated by the SNMP protocol entity and for which the value of the "ErrorStatus" component is "readOnly."
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutGenErrs { snmp 24 }
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Syntax: Counter
Definition: The total number valid SNMP PDUs which were generated by the SNMP protocol entity and for which the value of the "ErrorStatus" component is "genErr."
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutGetRequests { snmp 25 }
Syntax: Counter
Definition: The total number of SNMP Get-Request PDUs which have been generated by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutGetNexts { snmp 26 }
Syntax: Counter
Definition: The total number of SNMP Get-Next PDUs which have been generated by the SNMP protocol entity.
Access: read-only.
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Status: mandatory.
OBJECT: ------- snmpOutSetRequests { snmp 27 }
Syntax: Counter
Definition: The total number of SNMP Set-Request PDUs which have been generated by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutGetResponses { snmp 28 }
Syntax: Counter
Definition: The total number of SNMP Get-Response PDUs which have been generated by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpOutTraps { snmp 29 }
Syntax: Counter
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Definition: The total number of SNMP Trap PDUs which have been generated by the SNMP protocol entity.
Access: read-only.
Status: mandatory.
OBJECT: ------- snmpEnableAuthTraps { snmp 30 }
Syntax: INTEGER { enabled(1), disabled(2) }
Definition: Indicates whether the SNMP agent process is configured to generate authentication-failure traps.
7. Identification of OBJECT instances for use with the SNMP
The names for all object types in the MIB are defined explicitly either in the Internet-standard MIB or in other documents which conform to the naming conventions of the SMI. The SMI requires that conformant management protocols define mechanisms for identifying individual instances of those object types for a particular network element.
Each instance of any object type defined in the MIB is identified in SNMP operations by a unique name called its "variable name." In general, the name of an SNMP variable is an OBJECT IDENTIFIER of the form x.y, where x is the name of a non-aggregate object type defined
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in the MIB and y is an OBJECT IDENTIFIER fragment that, in a way specific to the named object type, identifies the desired instance.
This naming strategy admits the fullest exploitation of the semantics of the powerful SNMP get-next operator, because it assigns names for related variables so as to be contiguous in the lexicographical ordering of all variable names known in the MIB.
The type-specific naming of object instances is defined below for a number of classes of object types. Instances of an object type to which none of the following naming conventions are applicable are named by OBJECT IDENTIFIERs of the form x.0, where x is the name of said object type in the MIB definition.
For example, suppose one wanted to identify an instance of the variable sysDescr. The object class for sysDescr is:
iso org dod internet mgmt mib system sysDescr 1 3 6 1 2 1 1 1
Hence, the object type, x, would be 1.3.6.1.2.1.1.1 to which is appended an instance sub-identifier of 0. That is, 1.3.6.1.2.1.1.1.0 identifies the one and only instance of sysDescr.
The name of a subnetwork interface, s, is the OBJECT IDENTIFIER value of the form i, where i has the value of that instance of the ifIndex object type associated with s. For each object type, t, for which the defined name, n, has a prefix of ifEntry, an instance, i, of t is named by an OBJECT IDENTIFIER of the form n.s, where s is the name of the subnetwork interface about which i represents information.
For example, suppose one wanted to identify the instance of the variable ifType associated with interface 2. Accordingly, ifType.2 would identify the desired instance.
The name of an address translation entry, x, is an OBJECT IDENTIFIER of the form s.1.a.b.c.d, such that s is the value of that instance of the atIfIndex object type associated with x, the subidentifer "1" signifies the translation of an IP protocol address, and a.b.c.d is the IP address value (in the familiar "dot" notation) of that instance of the atNetAddress object type associated with x.
For each object type, t, for which the defined name, n, has a prefix of atEntry, an instance, i, of t is named by an OBJECT IDENTIFIER of
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the form n.y, where y is the name of the address translation entry about which i represents information.
For example, suppose one wanted to find the physical address of an entry in the address translation table (ARP cache) associated with an IP address of 89.1.1.42 and interface 3. Accordingly, atPhysAddress.3.1.89.1.1.42 would identify the desired instance.
The name of an IP-addressable network element, x, is the OBJECT IDENTIFIER of the form a.b.c.d such that a.b.c.d is the value (in the familiar "dot" notation) of that instance of the ipAdEntAddr object type associated with x.
For each object type, t, for which the defined name, n, has a prefix of ipAddrEntry, an instance, i, of t is named by an OBJECT IDENTIFIER of the form n.y, where y is the name of the IP- addressable network element about which i represents information.
For example, suppose one wanted to find the network mask of an entry in the IP interface table associated with an IP address of 89.1.1.42. Accordingly, ipAdEntNetMask.89.1.1.42 would identify the desired instance.
At the option of the agent, multiple entries for the same IP address may be visible. To realize this, the agent, while required to return a single entry for an IP address, x, of the form n.y, may also return information about other entries for the same IP address using the form n.y.z, where z is a implementation-dependendent small, non- negative integer. It is strongly recommended that the value of z correspond to the value of ipAddrIfIndex for that entry.
The name of an IP route, x, is the OBJECT IDENTIFIER of the form a.b.c.d such that a.b.c.d is the value (in the familiar "dot" notation) of that instance of the ipRouteDest object type associated with x.
For each object type, t, for which the defined name, n, has a prefix of ipRoutingEntry, an instance, i, of t is named by an OBJECT IDENTIFIER of the form n.y, where y is the name of the IP route about which i represents information.
For example, suppose one wanted to find the next hop of an entry in the IP routing table associated with the destination of 89.1.1.42. Accordingly, ipRouteNextHop.89.1.1.42 would identify the desired
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instance.
At the option of the agent, multiple routes to the same destination may be visible. To realize this, the agent, while required to return a single entry for an IP route, x, of the form n.y, may also return information about other routes to the same destination using the form n.y.z, where z is a implementation-dependendent small, non-negative integer.
The name of a cached IP address, x, is an OBJECT IDENTIFIER of the form s.a.b.c.d, such that s is the value of that instance of the ipNetToMediaIfIndex object type associated with the entry and a.b.c.d is the value (in the familiar "dot" notation) of the ipNetToMediaNetAddress object type associated with x.
For each object type, t, for which the defined name, n, has a prefix of ipNetToMediaEntry, an instance, i, of t is named by an OBJECT IDENTIFIER of the form n.y, where y is the name of the cached IP address about which i represents information.
For example, suppose one wanted to find the media address of an entry in the address translation table associated with a IP address of 192.52.180.1 and interface 3. Accordingly, ipNetToMediaPhysAddress.3.192.52.180.1 would identify the desired instance.
The name of a TCP connection, x, is the OBJECT IDENTIFIER of the form a.b.c.d.e.f.g.h.i.j such that a.b.c.d is the value (in the familiar "dot" notation) of that instance of the tcpConnLocalAddress object type associated with x and such that f.g.h.i is the value (in the familiar "dot" notation) of that instance of the tcpConnRemoteAddress object type associated with x and such that e is the value of that instance of the tcpConnLocalPort object type associated with x and such that j is the value of that instance of the tcpConnRemotePort object type associated with x.
For each object type, t, for which the defined name, n, has a prefix of tcpConnEntry, an instance, i, of t is named by an OBJECT IDENTIFIER of the form n.y, where y is the name of the TCP connection about which i represents information.
For example, suppose one wanted to find the state of a TCP connection between the local address of 89.1.1.42 on TCP port 21 and the remote address of 10.0.0.51 on TCP port 2059. Accordingly,
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tcpConnState.89.1.1.42.21.10.0.0.51.2059 would identify the desired instance.
The name of a UDP listener, x, is the OBJECT IDENTIFIER of the form a.b.c.d.e. such that a.b.c.d is the value (in the familiar "dot" notation) of that instance of the udpLocalAddress object type associated with x and such that e is the value of that instance of the udpLocalPort object type associated with x.
For each object type, t, for which the defined name, n, has a prefix of udpEntry, an instance, i, of t is named by an OBJECT IDENTIFIER of the form n.y, where y is the name of the UDP listener about which i represents information.
For example, suppose one wanted to determine if a UDP listener was present at the local address of 89.1.1.42 on UDP port 21. Accordingly, a successful retrieval of either udpLocalAddress.89.1.1.42.21 or udpLocalPort.89.1.1.42.21 would indicate this.
The name of an EGP neighbor, x, is the OBJECT IDENTIFIER of the form a.b.c.d such that a.b.c.d is the value (in the familiar "dot" notation) of that instance of the egpNeighAddr object type associated with x.
For each object type, t, for which the defined name, n, has a prefix of egpNeighEntry, an instance, i, of t is named by an OBJECT IDENTIFIER of the form n.y, where y is the name of the EGP neighbor about which i represents information.
For example, suppose one wanted to find the neighbor state for the IP address of 89.1.1.42. Accordingly, egpNeighState.89.1.1.42 would identify the desired instance.
This document was produced by the SNMP Working Group:
Karl Auerbach, Epilogue Technology David Bridgham, Epilogue Technology Brian Brown, Synoptics John Burress, Wellfleet Jeffrey D. Case, University of Tennessee at Knoxville James R. Davin, MIT-LCS
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Mark S. Fedor, PSI, Inc. Stan Froyd, ACC Satish Joshi, Synoptics Ken Key, University of Tennessee at Knoxville Gary Malkin, Proteon Randy Mayhew, University of Tennessee at Knoxville Keith McCloghrie, Hughes LAN Systems Marshall T. Rose, PSI, Inc. (chair) Greg Satz, cisco Martin Lee Schoffstall, PSI, Inc. Bob Stewart, Xyplex Geoff Thompson, Synoptics Bill Versteeg, Network Research Corporation Wengyik Yeong, PSI, Inc.
In addition, the comments of the following individuals are also acknolwedged:
Craig A. Finseth, Minnesota Supercomputer Center, Inc. Jeffrey C. Honig, Cornell University Theory Center Philip R. Karn, Bellcore David Waitzman, BBN
[1] Cerf, V., "IAB Recommendations for the Development of Internet Network Management Standards", RFC 1052, IAB, April 1988.
[2] Rose, M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based internets", RFC 1065, TWG, August 1988.
[3] McCloghrie K., and M. Rose,"Management Information Base for Network Management of TCP/IP-based internets", RFC 1066, TWG, August 1988.
[4] Cerf, V., "Report of the Second Ad Hoc Network Management Review Group", RFC 1109, IAB, August 1989.
[5] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "A Simple Network Management Protocol (SNMP)", RFC 1098, University of Tennessee at Knoxville, NYSERNet, Inc., Rensselaer Polytechnic Institute, MIT Laboratory for Computer Science, April 1989.
[6] Warrier, U., and L. Besaw, "Common Management Information Services and Protocol over TCP/IP (CMOT)", RFC 1095, Unisys Corporation, Hewlett-Packard, April 1989.
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[7] Postel, J., "Telnet Protocol Specification", RFC 854, USC/Information Sciences Institute, May 1983.
[8] Satz, G., "Experimental MIB Objects for the CLNP", Internet Working Group Request for Comments draft. Network Information Center, SRI International, Menlo Park, California, (in preparation).
[9] Information processing systems - Open Systems Interconnection, "Specification of Abstract Syntax Notation One (ASN.1)", International Organization for Standardization, International Standard 8824, December 1987.
[10] Information processing systems - Open Systems Interconnection, "Specification of Basic Encoding Rules for Abstract Notation One (ASN.1)", International Organization for Standardization. International Standard 8825, December 1987.
[12] Hagens, R., Hall, N., and M. Rose, "Use of the Internet as a subnetwork for experimentation with the OSI network layer", February, 1989.
[13] Rose, M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", RFC 1155, Performance Systems International and Hughes LAN Systems, May 1990.
[14] Case, J., Fedor, M., Schoffstall, M., and J. Davin, The Simple Network Management Protocol", RFC 1157, University of Tennessee at Knoxville, Performance Systems International, Performance Systems International, and the MIT Laboratory for Computer Science, May 1990.