during this interval.
Whenever an interface table entry is created (usually as a result of
system initialization), the relevant instance of ifAdminStatus is set
to down, and ifOperStatus will be down or notPresent.
An interface may be enabled in two ways: either as a result of
explicit management action (e.g. setting ifAdminStatus to up) or as a
result of the managed system's initialization process. When
ifAdminStatus changes to the up state, the related ifOperStatus
should do one of the following:
(1) Change to the up state if and only if the interface is able to
send and receive packets.
(2) Change to the lowerLayerDown state if and only if the interface
is prevented from entering the up state because of the state of
one or more of the interfaces beneath it in the interface
stack.
(3) Change to the dormant state if and only if the interface is
found to be operable, but the interface is waiting for other,
external, events to occur before it can transmit or receive
packets. Presumably when the expected events occur, the
interface will then change to the up state.
(4) Remain in the down state if an error or other fault condition
is detected on the interface.
(5) Change to the unknown state if, for some reason, the state of
the interface can not be ascertained.
(6) Change to the testing state if some test(s) must be performed
on the interface. Presumably after completion of the test, the
interface's state will change to up, dormant, or down, as
appropriate.
(7) Remain in the notPresent state if interface components are
missing.
3.1.14. IfOperStatus in an Interface Stack
When an interface is a part of an interface-stack, but is not the
lowest interface in the stack, then:
(1) ifOperStatus has the value 'up' if it is able to pass packets
due to one or more interfaces below it in the stack being 'up',
irrespective of whether other interfaces below it are 'down', '
dormant', 'notPresent', 'lowerLayerDown', 'unknown' or '
testing'.
(2) ifOperStatus may have the value 'up' or 'dormant' if one or
more interfaces below it in the stack are 'dormant', and all
others below it are either 'down', 'dormant', 'notPresent', '
lowerLayerDown', 'unknown' or 'testing'.
(3) ifOperStatus has the value 'lowerLayerDown' while all
interfaces below it in the stack are either 'down', '
notPresent', 'lowerLayerDown', or 'testing'.
3.1.15. Traps
The exact definition of when linkUp and linkDown traps are generated
has been changed to reflect the changes to ifAdminStatus and
ifOperStatus. Operational experience indicates that management
stations are most concerned with an interface being in the down state
and the fact that this state may indicate a failure. Thus, it is
most useful to instrument transitions into/out of either the up state
or the down state.
Instrumenting transitions into or out of the up state was rejected
since it would have the drawback that a demand interface might have
many transitions between up and dormant, leading to many linkUp traps
and no linkDown traps. Furthermore, if a node's only interface is
the demand interface, then a transition to dormant would entail
generation of a linkDown trap, necessitating bringing the link to the
up state (and a linkUp trap)!!
On the other hand, instrumenting transitions into or out of the down
state (to/from all other states except notPresent) has the
advantages:
(1) A transition into the down state (from a state other than
notPresent) will occur when an error is detected on an
interface. Error conditions are presumably of great interest
to network managers.
(2) Departing the down state (to a state other than the notPresent
state) generally indicates that the interface is going to
either up or dormant, both of which are considered "healthy"
states.
Furthermore, it is believed that generating traps on transitions into
or out of the down state (except to/from the notPresent state) is
generally consistent with current usage and interpretation of these
traps by manager stations.
Transitions to/from the notPresent state are concerned with the
insertion and removal of hardware, and are outside the scope of these
traps.
Therefore, this memo defines that LinkUp and linkDown traps are
generated just after ifOperStatus leaves, or just before it enters,
the down state, respectively; except that LinkUp and linkDown traps
are never generated on transitions to/from the notPresent state. For
the purpose of deciding when these traps occur, the lowerLayerDown
state and the down state are considered to be equivalent, i.e., there
is no trap on transition from lowerLayerDown into down, and there is
a trap on transition from any other state except down (and
notPresent) into lowerLayerDown.
Note that this definition allows a node with only one interface to
transmit a linkDown trap before that interface goes down. (Of
course, when the interface is going down because of a failure
condition, the linkDown trap probably cannot be successfully
transmitted anyway.)
Some interfaces perform a link "training" function when trying to
bring the interface up. In the event that such an interface were
defective, then the training function would fail and the interface
would remain down, and the training function might be repeated at
appropriate intervals. If the interface, while performing this
training function, were considered to the in the testing state, then
linkUp and linkDown traps would be generated for each start and end
of the training function. This is not the intent of the linkUp and
linkDown traps, and therefore, while performing such a training
function, the interface's state should be represented as down.
An exception to the above generation of linkUp/linkDown traps on
changes in ifOperStatus, occurs when an interface is "flapping",
i.e., when it is rapidly oscillating between the up and down states.
If traps were generated for each such oscillation, the network and
the network management system would be flooded with unnecessary
traps. In such a situation, the agent should limit the rate at which
it generates traps.
3.1.16. ifSpecific
The original definition of the OBJECT IDENTIFIER value of ifSpecific
was not sufficiently clear. As a result, different implementors used
it differently, and confusion resulted. Some implementations set the
value of ifSpecific to the OBJECT IDENTIFIER that defines the media-
specific MIB, i.e., the "foo" of:
foo OBJECT IDENTIFIER ::= { transmission xxx }
while others set it to be OBJECT IDENTIFIER of the specific table or
entry in the appropriate media-specific MIB (i.e., fooTable or
fooEntry), while still others set it be the OBJECT IDENTIFIER of the
index object of the table's row, including instance identifier,
(i.e., fooIfIndex.ifIndex). A definition based on the latter would
not be sufficient unless it also allowed for media-specific MIBs
which include several tables, where each table has its own
(different) indexing.
The only definition that can both be made explicit and can cover all
the useful situations is to have ifSpecific be the most general value
for the media-specific MIB module (the first example given above).
This effectively makes it redundant because it contains no more
information than is provided by ifType. Thus, ifSpecific has been
deprecated.
3.1.17. Creation/Deletion of Interfaces
While some interfaces, for example, most physical interfaces, cannot
be created via network management, other interfaces such as logical
interfaces sometimes can be. The ifTable contains only generic
information about an interface. Almost all 'create-able' interfaces
have other, media-specific, information through which configuration
parameters may be supplied prior to creating such an interface.
Thus, the ifTable does not itself support the creation or deletion of
an interface (specifically, it has no RowStatus [6] column). Rather,
if a particular interface type supports the dynamic creation and/or
deletion of an interface of that type, then that media-specific MIB
should include an appropriate RowStatus object (see the ATM LAN-
Emulation Client MIB [20] for an example of a MIB which does this).
Typically, when such a RowStatus object is created/deleted, then the
conceptual row in the ifTable appears/disappears as a by-product, and
an ifIndex value (chosen by the agent) is stored in an appropriate
object in the media-specific MIB.
3.1.18. All Values Must be Known
There are a number of situations where an agent does not know the
value of one or more objects for a particular interface. In all such
circumstances, an agent MUST NOT instantiate an object with an
incorrect value; rather, it MUST respond with the appropriate
error/exception condition (e.g., noSuchInstance or noSuchName).
One example is where an agent is unable to count the occurrences
defined by one (or more) of the ifTable counters. In this
circumstance, the agent MUST NOT instantiate the particular counter
with a value of, say, zero. To do so would be to provide mis-
information to a network management application reading the zero
value, and thereby assuming that there have been no occurrences of
the event (e.g., no input errors because ifInErrors is always zero).
Sometimes the lack of knowledge of an object's value is temporary.
For example, when the MTU of an interface is a configured value and a
device dynamically learns the configured value through (after)
exchanging messages over the interface (e.g., ATM LAN-Emulation
[20]). In such a case, the value is not known until after the
ifTable entry has already been created. In such a case, the ifTable
entry should be created without an instance of the object whose value
is unknown; later, when the value becomes known, the missing object
can then be instantiated (e.g., the instance of ifMtu is only
instantiated once the interface's MTU becomes known).
As a result of this "known values" rule, management applications MUST
be able to cope with the responses to retrieving the object instances
within a conceptual row of the ifTable revealing that some of the
row's columnar objects are missing/not available.
4. Media-Specific MIB Applicability
The exact use and semantics of many objects in this MIB are open to
some interpretation. This is a result of the generic nature of this
MIB. It is not always possible to come up with specific,
unambiguous, text that covers all cases and yet preserves the generic
nature of the MIB.
Therefore, it is incumbent upon a media-specific MIB designer to,
wherever necessary, clarify the use of the objects in this MIB with
respect to the media-specific MIB.
Specific areas of clarification include
Layering Model
The media-specific MIB designer MUST completely and unambiguously
specify the layering model used. Each individual sub-layer must
be identified, as must the ifStackTable's portrayal of the
relationship(s) between the sub-layers.
Virtual Circuits
The media-specific MIB designer MUST specify whether virtual
circuits are assigned entries in the ifTable or not. If they are,
compelling rationale must be presented.
ifRcvAddressTable
The media-specific MIB designer MUST specify the applicability of
the ifRcvAddressTable.
ifType
For each of the ifType values to which the media-specific MIB
applies, it must specify the mapping of ifType values to media-
specific MIB module(s) and instances of MIB objects within those
modules.
ifXxxOctets
The definitions of ifInOctets and ifOutOctets (and similarly,
ifHCInOctets and ifHCOutOctets) specify that their values include
framing characters. The media-specific MIB designer MUST specify
any special conditions of the media concerning the inclusion of
framing characters, especially with respect to frames with errors.
However, wherever this interface MIB is specific in the semantics,
DESCRIPTION, or applicability of objects, the media-specific MIB
designer MUST NOT change said semantics, DESCRIPTION, or
applicability.
5. Overview
This MIB consists of 4 tables:
ifTable
This table is the ifTable from MIB-II.
ifXTable
This table contains objects that have been added to the Interface
MIB as a result of the Interface Evolution effort, or replacements
for objects of the original (MIB-II) ifTable that were deprecated
because the semantics of said objects have significantly changed.
This table also contains objects that were previously in the
ifExtnsTable.
ifStackTable
This table contains objects that define the relationships among
the sub-layers of an interface.
ifRcvAddressTable
This table contains objects that are used to define the media-
level addresses which this interface will receive. This table is
a generic table. The designers of media-specific MIBs must define
exactly how this table applies to their specific MIB.
6. Interfaces Group Definitions
IF-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, Counter32, Gauge32, Counter64,
Integer32, TimeTicks, mib-2,
NOTIFICATION-TYPE FROM SNMPv2-SMI
TEXTUAL-CONVENTION, DisplayString,
PhysAddress, TruthValue, RowStatus,
TimeStamp, AutonomousType, TestAndIncr FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP,
NOTIFICATION-GROUP FROM SNMPv2-CONF
snmpTraps FROM SNMPv2-MIB
IANAifType FROM IANAifType-MIB;
ifMIB MODULE-IDENTITY
LAST-UPDATED "200006140000Z"
ORGANIZATION "IETF Interfaces MIB Working Group"
CONTACT-INFO
" Keith McCloghrie
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
US
408-526-5260
kzm@cisco.com"
DESCRIPTION
"The MIB module to describe generic objects for network
interface sub-layers. This MIB is an updated version of
MIB-II's ifTable, and incorporates the extensions defined in
RFC1229."
REVISION "200006140000Z"
DESCRIPTION
"Clarifications agreed upon by the Interfaces MIB WG, and
published as RFC2863."
REVISION "199602282155Z"
DESCRIPTION
"Revisions made by the Interfaces MIB WG, and published in
RFC2233."
REVISION "199311082155Z"
DESCRIPTION
"Initial revision, published as part of RFC1573."
::= { mib-2 31 }
ifMIBObjects OBJECT IDENTIFIER ::= { ifMIB 1 }
interfaces OBJECT IDENTIFIER ::= { mib-2 2 }
--
-- Textual Conventions
--
-- OwnerString has the same semantics as used in RFC1271
OwnerString ::= TEXTUAL-CONVENTION
DISPLAY-HINT "255a"
STATUS deprecated
DESCRIPTION
"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: ASCII
form of the manager station's transport address, management
station name (e.g., domain name), network management
personnel'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
'agent'."
SYNTAX OCTET STRING (SIZE(0..255))
-- InterfaceIndex contains the semantics of ifIndex and should be used
-- for any objects defined in other MIB modules that need these semantics.
InterfaceIndex ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"A unique value, greater than zero, for each interface or
interface sub-layer in the managed system. It is
recommended that values are assigned contiguously starting
from 1. The value for each interface sub-layer must remain
constant at least from one re-initialization of the entity's
network management system to the next re-initialization."
SYNTAX Integer32 (1..2147483647)
InterfaceIndexOrZero ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"This textual convention is an extension of the
InterfaceIndex convention. The latter defines a greater
than zero value used to identify an interface or interface
sub-layer in the managed system. This extension permits the
additional value of zero. the value zero is object-specific
and must therefore be defined as part of the description of
any object which uses this syntax. Examples of the usage of
zero might include situations where interface was unknown,
or when none or all interfaces need to be referenced."
SYNTAX Integer32 (0..2147483647)
ifNumber OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of network interfaces (regardless of their
current state) present on this system."
::= { interfaces 1 }
ifTableLastChange OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of sysUpTime at the time of the last creation or
deletion of an entry in the ifTable. If the number of
entries has been unchanged since the last re-initialization
of the local network management subsystem, then this object
contains a zero value."
::= { ifMIBObjects 5 }
-- the Interfaces table
-- The Interfaces table contains information on the entity's
-- interfaces. Each sub-layer below the internetwork-layer
-- of a network interface is considered to be an interface.
ifTable OBJECT-TYPE
SYNTAX SEQUENCE OF IfEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of interface entries. The number of entries is
given by the value of ifNumber."
::= { interfaces 2 }
ifEntry OBJECT-TYPE
SYNTAX IfEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry containing management information applicable to a
particular interface."
INDEX { ifIndex }
::= { ifTable 1 }
IfEntry ::=
SEQUENCE {
ifIndex InterfaceIndex,
ifDescr DisplayString,
ifType IANAifType,
ifMtu Integer32,
ifSpeed Gauge32,
ifPhysAddress PhysAddress,
ifAdminStatus INTEGER,
ifOperStatus INTEGER,
ifLastChange TimeTicks,
ifInOctets Counter32,
ifInUcastPkts Counter32,
ifInNUcastPkts Counter32, -- deprecated
ifInDiscards Counter32,
ifInErrors Counter32,
ifInUnknownProtos Counter32,
ifOutOctets Counter32,
ifOutUcastPkts Counter32,
ifOutNUcastPkts Counter32, -- deprecated
ifOutDiscards Counter32,
ifOutErrors Counter32,
ifOutQLen Gauge32, -- deprecated
ifSpecific OBJECT IDENTIFIER -- deprecated
}
ifIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A unique value, greater than zero, for each interface. It
is recommended that values are assigned contiguously
starting from 1. The value for each interface sub-layer
must remain constant at least from one re-initialization of
the entity's network management system to the next re-
initialization."
::= { ifEntry 1 }
ifDescr OBJECT-TYPE
SYNTAX DisplayString (SIZE (0..255))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A textual string containing information about the
interface. This string should include the name of the
manufacturer, the product name and the version of the
interface hardware/software."
::= { ifEntry 2 }
ifType OBJECT-TYPE
SYNTAX IANAifType
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The type of interface. Additional values for ifType are
assigned by the Internet Assigned Numbers Authority (IANA),
through updating the syntax of the IANAifType textual
convention."
::= { ifEntry 3 }
ifMtu OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The size of the largest packet which can be sent/received
on the interface, specified in octets. For interfaces that
are used for transmitting network datagrams, this is the
size of the largest network datagram that can be sent on the
interface."
::= { ifEntry 4 }
ifSpeed OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An estimate of the interface's current bandwidth in bits
per second. For interfaces which do not vary in bandwidth
or for those where no accurate estimation can be made, this
object should contain the nominal bandwidth. If the
bandwidth of the interface is greater than the maximum value
reportable by this object then this object should report its
maximum value (4,294,967,295) and ifHighSpeed must be used
to report the interace's speed. For a sub-layer which has
no concept of bandwidth, this object should be zero."
::= { ifEntry 5 }
ifPhysAddress OBJECT-TYPE
SYNTAX PhysAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The interface's address at its protocol sub-layer. For
example, for an 802.x interface, this object normally
contains a MAC address. The interface's media-specific MIB
must define the bit and byte ordering and the format of the
value of this object. For interfaces which do not have such
an address (e.g., a serial line), this object should contain
an octet string of zero length."
::= { ifEntry 6 }
ifAdminStatus OBJECT-TYPE
SYNTAX INTEGER {
up(1), -- ready to pass packets
down(2),
testing(3) -- in some test mode
}
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The desired state of the interface. The testing(3) state
indicates that no operational packets can be passed. When a
managed system initializes, all interfaces start with
ifAdminStatus in the down(2) state. As a result of either
explicit management action or per configuration information
retained by the managed system, ifAdminStatus is then
changed to either the up(1) or testing(3) states (or remains
in the down(2) state)."
::= { ifEntry 7 }
ifOperStatus OBJECT-TYPE
SYNTAX INTEGER {
up(1), -- ready to pass packets
down(2),
testing(3), -- in some test mode
unknown(4), -- status can not be determined
-- for some reason.
dormant(5),
notPresent(6), -- some component is missing
lowerLayerDown(7) -- down due to state of
-- lower-layer interface(s)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The current operational state of the interface. The
testing(3) state indicates that no operational packets can
be passed. If ifAdminStatus is down(2) then ifOperStatus
should be down(2). If ifAdminStatus is changed to up(1)
then ifOperStatus should change to up(1) if the interface is
ready to transmit and receive network traffic; it should
change to dormant(5) if the interface is waiting for
external actions (such as a serial line waiting for an
incoming connection); it should remain in the down(2) state
if and only if there is a fault that prevents it from going
to the up(1) state; it should remain in the notPresent(6)
state if the interface has missing (typically, hardware)
components."
::= { ifEntry 8 }
ifLastChange OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"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."
::= { ifEntry 9 }
ifInOctets OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of octets received on the interface,
including framing characters.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 10 }
ifInUcastPkts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of packets, delivered by this sub-layer to a
higher (sub-)layer, which were not addressed to a multicast
or broadcast address at this sub-layer.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 11 }
ifInNUcastPkts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"The number of packets, delivered by this sub-layer to a
higher (sub-)layer, which were addressed to a multicast or
broadcast address at this sub-layer.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime.
This object is deprecated in favour of ifInMulticastPkts and
ifInBroadcastPkts."
::= { ifEntry 12 }
ifInDiscards OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of inbound packets which were chosen to be
discarded even though no errors had been detected to prevent
their being deliverable to a higher-layer protocol. One
possible reason for discarding such a packet could be to
free up buffer space.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 13 }
ifInErrors OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"For packet-oriented interfaces, the number of inbound
packets that contained errors preventing them from being
deliverable to a higher-layer protocol. For character-
oriented or fixed-length interfaces, the number of inbound
transmission units that contained errors preventing them
from being deliverable to a higher-layer protocol.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 14 }
ifInUnknownProtos OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"For packet-oriented interfaces, the number of packets
received via the interface which were discarded because of
an unknown or unsupported protocol. For character-oriented
or fixed-length interfaces that support protocol
multiplexing the number of transmission units received via
the interface which were discarded because of an unknown or
unsupported protocol. For any interface that does not
support protocol multiplexing, this counter will always be
0.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 15 }
ifOutOctets OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of octets transmitted out of the
interface, including framing characters.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 16 }
ifOutUcastPkts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of packets that higher-level protocols
requested be transmitted, and which were not addressed to a
multicast or broadcast address at this sub-layer, including
those that were discarded or not sent.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 17 }
ifOutNUcastPkts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"The total number of packets that higher-level protocols
requested be transmitted, and which were addressed to a
multicast or broadcast address at this sub-layer, including
those that were discarded or not sent.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime.
This object is deprecated in favour of ifOutMulticastPkts
and ifOutBroadcastPkts."
::= { ifEntry 18 }
ifOutDiscards OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of outbound packets which were chosen to be
discarded even though no errors had been detected to prevent
their being transmitted. One possible reason for discarding
such a packet could be to free up buffer space.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 19 }
ifOutErrors OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"For packet-oriented interfaces, the number of outbound
packets that could not be transmitted because of errors.
For character-oriented or fixed-length interfaces, the
number of outbound transmission units that could not be
transmitted because of errors.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifEntry 20 }
ifOutQLen OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"The length of the output packet queue (in packets)."
::= { ifEntry 21 }
ifSpecific OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
MAX-ACCESS read-only
STATUS deprecated
DESCRIPTION
"A reference to MIB definitions specific to the particular
media being used to realize the interface. It is
recommended that this value point to an instance of a MIB
object in the media-specific MIB, i.e., that this object
have the semantics associated with the InstancePointer
textual convention defined in RFC2579. In fact, it is
recommended that the media-specific MIB specify what value
ifSpecific should/can take for values of ifType. If no MIB
definitions specific to the particular media are available,
the value should be set to the OBJECT IDENTIFIER { 0 0 }."
::= { ifEntry 22 }
--
-- Extension to the interface table
--
-- This table replaces the ifExtnsTable table.
--
ifXTable OBJECT-TYPE
SYNTAX SEQUENCE OF IfXEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of interface entries. The number of entries is
given by the value of ifNumber. This table contains
additional objects for the interface table."
::= { ifMIBObjects 1 }
ifXEntry OBJECT-TYPE
SYNTAX IfXEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry containing additional management information
applicable to a particular interface."
AUGMENTS { ifEntry }
::= { ifXTable 1 }
IfXEntry ::=
SEQUENCE {
ifName DisplayString,
ifInMulticastPkts Counter32,
ifInBroadcastPkts Counter32,
ifOutMulticastPkts Counter32,
ifOutBroadcastPkts Counter32,
ifHCInOctets Counter64,
ifHCInUcastPkts Counter64,
ifHCInMulticastPkts Counter64,
ifHCInBroadcastPkts Counter64,
ifHCOutOctets Counter64,
ifHCOutUcastPkts Counter64,
ifHCOutMulticastPkts Counter64,
ifHCOutBroadcastPkts Counter64,
ifLinkUpDownTrapEnable INTEGER,
ifHighSpeed Gauge32,
ifPromiscuousMode TruthValue,
ifConnectorPresent TruthValue,
ifAlias DisplayString,
ifCounterDiscontinuityTime TimeStamp
}
ifName OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.
If there is no local name, or this object is otherwise not
applicable, then this object contains a zero-length string."
::= { ifXEntry 1 }
ifInMulticastPkts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of packets, delivered by this sub-layer to a
higher (sub-)layer, which were addressed to a multicast
address at this sub-layer. For a MAC layer protocol, this
includes both Group and Functional addresses.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 2 }
ifInBroadcastPkts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of packets, delivered by this sub-layer to a
higher (sub-)layer, which were addressed to a broadcast
address at this sub-layer.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 3 }
ifOutMulticastPkts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of packets that higher-level protocols
requested be transmitted, and which were addressed to a
multicast address at this sub-layer, including those that
were discarded or not sent. For a MAC layer protocol, this
includes both Group and Functional addresses.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 4 }
ifOutBroadcastPkts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of packets that higher-level protocols
requested be transmitted, and which were addressed to a
broadcast address at this sub-layer, including those that
were discarded or not sent.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 5 }
--
-- High Capacity Counter objects. These objects are all
-- 64 bit versions of the "basic" ifTable counters. These
-- objects all have the same basic semantics as their 32-bit
-- counterparts, however, their syntax has been extended
-- to 64 bits.
--
ifHCInOctets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of octets received on the interface,
including framing characters. This object is a 64-bit
version of ifInOctets.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 6 }
ifHCInUcastPkts OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of packets, delivered by this sub-layer to a
higher (sub-)layer, which were not addressed to a multicast
or broadcast address at this sub-layer. This object is a
64-bit version of ifInUcastPkts.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 7 }
ifHCInMulticastPkts OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of packets, delivered by this sub-layer to a
higher (sub-)layer, which were addressed to a multicast
address at this sub-layer. For a MAC layer protocol, this
includes both Group and Functional addresses. This object
is a 64-bit version of ifInMulticastPkts.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 8 }
ifHCInBroadcastPkts OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of packets, delivered by this sub-layer to a
higher (sub-)layer, which were addressed to a broadcast
address at this sub-layer. This object is a 64-bit version
of ifInBroadcastPkts.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 9 }
ifHCOutOctets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of octets transmitted out of the
interface, including framing characters. This object is a
64-bit version of ifOutOctets.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 10 }
ifHCOutUcastPkts OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of packets that higher-level protocols
requested be transmitted, and which were not addressed to a
multicast or broadcast address at this sub-layer, including
those that were discarded or not sent. This object is a
64-bit version of ifOutUcastPkts.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 11 }
ifHCOutMulticastPkts OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of packets that higher-level protocols
requested be transmitted, and which were addressed to a
multicast address at this sub-layer, including those that
were discarded or not sent. For a MAC layer protocol, this
includes both Group and Functional addresses. This object
is a 64-bit version of ifOutMulticastPkts.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 12 }
ifHCOutBroadcastPkts OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of packets that higher-level protocols
requested be transmitted, and which were addressed to a
broadcast address at this sub-layer, including those that
were discarded or not sent. This object is a 64-bit version
of ifOutBroadcastPkts.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime."
::= { ifXEntry 13 }
ifLinkUpDownTrapEnable OBJECT-TYPE
SYNTAX INTEGER { enabled(1), disabled(2) }
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Indicates whether linkUp/linkDown traps should be generated
for this interface.
By default, this object should have the value enabled(1) for
interfaces which do not operate on 'top' of any other
interface (as defined in the ifStackTable), and disabled(2)
otherwise."
::= { ifXEntry 14 }
ifHighSpeed OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An estimate of the interface's current bandwidth in units
of 1,000,000 bits per second. If this object reports a
value of `n' then the speed of the interface is somewhere in
the range of `n-500,000' to `n+499,999'. For interfaces
which do not vary in bandwidth or for those where no
accurate estimation can be made, this object should contain
the nominal bandwidth. For a sub-layer which has no concept
of bandwidth, this object should be zero."
::= { ifXEntry 15 }
ifPromiscuousMode OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object has a value of false(2) if this interface only
accepts packets/frames that are addressed to this station.
This object has a value of true(1) when the station accepts
all packets/frames transmitted on the media. The value
true(1) is only legal on certain types of media. If legal,
setting this object to a value of true(1) may require the
interface to be reset before becoming effective.
The value of ifPromiscuousMode does not affect the reception
of broadcast and multicast packets/frames by the interface."
::= { ifXEntry 16 }
ifConnectorPresent OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object has the value 'true(1)' if the interface
sublayer has a physical connector and the value 'false(2)'
otherwise."
::= { ifXEntry 17 }
ifAlias OBJECT-TYPE
SYNTAX DisplayString (SIZE(0..64))
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object is an 'alias' name for the interface as
specified by a network manager, and provides a non-volatile
'handle' for the interface.
On the first instantiation of an interface, the value of
ifAlias associated with that interface is the zero-length
string. As and when a value is written into an instance of
ifAlias through a network management set operation, then the
agent must retain the supplied value in the ifAlias instance
associated with the same interface for as long as that
interface remains instantiated, including across all re-
initializations/reboots of the network management system,
including those which result in a change of the interface's
ifIndex value.
An example of the value which a network manager might store
in this object for a WAN interface is the (Telco's) circuit
number/identifier of the interface.
Some agents may support write-access only for interfaces
having particular values of ifType. An agent which supports
write access to this object is required to keep the value in
non-volatile storage, but it may limit the length of new
values depending on how much storage is already occupied by
the current values for other interfaces."
::= { ifXEntry 18 }
ifCounterDiscontinuityTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of sysUpTime on the most recent occasion at which
any one or more of this interface's counters suffered a
discontinuity. The relevant counters are the specific
instances associated with this interface of any Counter32 or
Counter64 object contained in the ifTable or ifXTable. If
no such discontinuities have occurred since the last re-
initialization of the local management subsystem, then this
object contains a zero value."
::= { ifXEntry 19 }
-- The Interface Stack Group
--
-- Implementation of this group is optional, but strongly recommended
-- for all systems
--
ifStackTable OBJECT-TYPE
SYNTAX SEQUENCE OF IfStackEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The table containing information on the relationships
between the multiple sub-layers of network interfaces. In
particular, it contains information on which sub-layers run
'on top of' which other sub-layers, where each sub-layer
corresponds to a conceptual row in the ifTable. For
example, when the sub-layer with ifIndex value x runs over
the sub-layer with ifIndex value y, then this table
contains:
ifStackStatus.x.y=active
For each ifIndex value, I, which identifies an active
interface, there are always at least two instantiated rows
in this table associated with I. For one of these rows, I
is the value of ifStackHigherLayer; for the other, I is the
value of ifStackLowerLayer. (If I is not involved in
multiplexing, then these are the only two rows associated
with I.)
For example, two rows exist even for an interface which has
no others stacked on top or below it:
ifStackStatus.0.x=active
ifStackStatus.x.0=active "
::= { ifMIBObjects 2 }
ifStackEntry OBJECT-TYPE
SYNTAX IfStackEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Information on a particular relationship between two sub-
layers, specifying that one sub-layer runs on 'top' of the
other sub-layer. Each sub-layer corresponds to a conceptual
row in the ifTable."
INDEX { ifStackHigherLayer, ifStackLowerLayer }
::= { ifStackTable 1 }
IfStackEntry ::=
SEQUENCE {
ifStackHigherLayer InterfaceIndexOrZero,
ifStackLowerLayer InterfaceIndexOrZero,
ifStackStatus RowStatus
}
ifStackHigherLayer OBJECT-TYPE
SYNTAX InterfaceIndexOrZero
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The value of ifIndex corresponding to the higher sub-layer
of the relationship, i.e., the sub-layer which runs on 'top'
of the sub-layer identified by the corresponding instance of
ifStackLowerLayer. If there is no higher sub-layer (below
the internetwork layer), then this object has the value 0."
::= { ifStackEntry 1 }
ifStackLowerLayer OBJECT-TYPE
SYNTAX InterfaceIndexOrZero
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The value of ifIndex corresponding to the lower sub-layer
of the relationship, i.e., the sub-layer which runs 'below'
the sub-layer identified by the corresponding instance of
ifStackHigherLayer. If there is no lower sub-layer, then
this object has the value 0."
::= { ifStackEntry 2 }
ifStackStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of the relationship between two sub-layers.
Changing the value of this object from 'active' to
'notInService' or 'destroy' will likely have consequences up
and down the interface stack. Thus, write access to this
object is likely to be inappropriate for some types of
interfaces, and many implementations will choose not to
support write-access for any type of interface."
::= { ifStackEntry 3 }
ifStackLastChange OBJECT-TYPE
SYNTAX TimeTicks
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of sysUpTime at the time of the last change of
the (whole) interface stack. A change of the interface
stack is defined to be any creation, deletion, or change in
value of any instance of ifStackStatus. If the interface
stack has been unchanged since the last re-initialization of
the local network management subsystem, then this object
contains a zero value."
::= { ifMIBObjects 6 }
-- Generic Receive Address Table
--
-- This group of objects is mandatory for all types of
-- interfaces which can receive packets/frames addressed to
-- more than one address.
--
-- This table replaces the ifExtnsRcvAddr table. The main
-- difference is that this table makes use of the RowStatus
-- textual convention, while ifExtnsRcvAddr did not.
ifRcvAddressTable OBJECT-TYPE
SYNTAX SEQUENCE OF IfRcvAddressEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table contains an entry for each address (broadcast,
multicast, or uni-cast) for which the system will receive
packets/frames on a particular interface, except as follows:
- for an interface operating in promiscuous mode, entries
are only required for those addresses for which the system
would receive frames were it not operating in promiscuous
mode.
- for 802.5 functional addresses, only one entry is