module IF-MIB {

    yang-version 1;

    namespace
      "urn:ietf:params:xml:ns:yang:smiv2:IF-MIB";

    prefix IF-MIB;

    import IANAifType-MIB {
      prefix ianaiftype-mib;
    }
    import SNMPv2-TC {
      prefix snmpv2-tc;
    }
    import ietf-yang-smiv2 {
      prefix smiv2;
    }
    import ietf-yang-types {
      prefix yang;
    }

    organization
      "IETF Interfaces MIB Working Group";

    contact
      "   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
RFC 1229.";

    revision "2000-06-14" {
      description
        "Clarifications agreed upon by the Interfaces MIB WG, and
published as RFC 2863.";
    }

    revision "1996-02-28" {
      description
        "Revisions made by the Interfaces MIB WG, and published in
RFC 2233.";
    }

    revision "1993-11-08" {
      description
        "Initial revision, published as part of RFC 1573.";
    }

    smiv2:alias "ifXTable" {
      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.";
      smiv2:oid "1.3.6.1.2.1.31.1.1";
    }
    smiv2:alias "ifXEntry" {
      description "An entry containing additional management information
applicable to a particular interface.";
      smiv2:oid "1.3.6.1.2.1.31.1.1.1";
    }
    smiv2:alias "ifTestTable" {
      status "deprecated";
      description "This table contains one entry per interface.  It defines
objects which allow a network manager to instruct an agent
to test an interface for various faults.  Tests for an
interface are defined in the media-specific MIB for that
interface.  After invoking a test, the object ifTestResult
can be read to determine the outcome.  If an agent can not
perform the test, ifTestResult is set to so indicate.  The
object ifTestCode can be used to provide further test-
specific or interface-specific (or even enterprise-specific)
information concerning the outcome of the test.  Only one
test can be in progress on each interface at any one time.
If one test is in progress when another test is invoked, the
second test is rejected.  Some agents may reject a test when
a prior test is active on another interface.

Before starting a test, a manager-station must first obtain
'ownership' of the entry in the ifTestTable for the
interface to be tested.  This is accomplished with the
ifTestId and ifTestStatus objects as follows:

try_again:
  get (ifTestId, ifTestStatus)
  while (ifTestStatus != notInUse)
      /*
       * Loop while a test is running or some other
       * manager is configuring a test.
       */
      short delay
      get (ifTestId, ifTestStatus)
  }

  /*
   * Is not being used right now -- let's compete
   * to see who gets it.
   */
  lock_value = ifTestId

  if ( set(ifTestId = lock_value, ifTestStatus = inUse,

	   ifTestOwner = 'my-IP-address') == FAILURE)
      /*
       * Another manager got the ifTestEntry -- go
       * try again
       */
      goto try_again;

  /*
   * I have the lock
   */
  set up any test parameters.

  /*
   * This starts the test
   */
  set(ifTestType = test_to_run);

  wait for test completion by polling ifTestResult

  when test completes, agent sets ifTestResult
       agent also sets ifTestStatus = 'notInUse'

  retrieve any additional test results, and ifTestId

  if (ifTestId == lock_value+1) results are valid

A manager station first retrieves the value of the
appropriate ifTestId and ifTestStatus objects, periodically
repeating the retrieval if necessary, until the value of
ifTestStatus is 'notInUse'.  The manager station then tries
to set the same ifTestId object to the value it just
retrieved, the same ifTestStatus object to 'inUse', and the
corresponding ifTestOwner object to a value indicating
itself.  If the set operation succeeds then the manager has
obtained ownership of the ifTestEntry, and the value of the
ifTestId object is incremented by the agent (per the
semantics of TestAndIncr).  Failure of the set operation
indicates that some other manager has obtained ownership of
the ifTestEntry.

Once ownership is obtained, any test parameters can be
setup, and then the test is initiated by setting ifTestType.
On completion of the test, the agent sets ifTestStatus to
'notInUse'.  Once this occurs, the manager can retrieve the
results.  In the (rare) event that the invocation of tests
by two network managers were to overlap, then there would be
a possibility that the first test's results might be
overwritten by the second test's results prior to the first
results being read.  This unlikely circumstance can be
detected by a network manager retrieving ifTestId at the
same time as retrieving the test results, and ensuring that
the results are for the desired request.

If ifTestType is not set within an abnormally long period of
time after ownership is obtained, the agent should time-out
the manager, and reset the value of the ifTestStatus object
back to 'notInUse'.  It is suggested that this time-out
period be 5 minutes.

In general, a management station must not retransmit a
request to invoke a test for which it does not receive a
response; instead, it properly inspects an agent's MIB to
determine if the invocation was successful.  Only if the
invocation was unsuccessful, is the invocation request
retransmitted.

Some tests may require the interface to be taken off-line in
order to execute them, or may even require the agent to
reboot after completion of the test.  In these
circumstances, communication with the management station
invoking the test may be lost until after completion of the
test.  An agent is not required to support such tests.
However, if such tests are supported, then the agent should
make every effort to transmit a response to the request
which invoked the test prior to losing communication.  When
the agent is restored to normal service, the results of the
test are properly made available in the appropriate objects.
Note that this requires that the ifIndex value assigned to
an interface must be unchanged even if the test causes a
reboot.  An agent must reject any test for which it cannot,
perhaps due to resource constraints, make available at least
the minimum amount of information after that test
completes.";
      smiv2:oid "1.3.6.1.2.1.31.1.3";
    }
    smiv2:alias "ifTestEntry" {
      status "deprecated";
      description "An entry containing objects for invoking tests on an
interface.";
      smiv2:oid "1.3.6.1.2.1.31.1.3.1";
    }
    smiv2:alias "interfaces" {
      smiv2:oid "1.3.6.1.2.1.2";
    }
    smiv2:alias "ifMIB" {
      smiv2:oid "1.3.6.1.2.1.31";
    }
    smiv2:alias "ifMIBObjects" {
      smiv2:oid "1.3.6.1.2.1.31.1";
    }
    smiv2:alias "ifConformance" {
      smiv2:oid "1.3.6.1.2.1.31.2";
    }
    smiv2:alias "ifGroups" {
      smiv2:oid "1.3.6.1.2.1.31.2.1";
    }
    smiv2:alias "ifCompliances" {
      smiv2:oid "1.3.6.1.2.1.31.2.2";
    }

    typedef OwnerString {
      type string {
        smiv2: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'.";
    }

    typedef InterfaceIndex {
      type int32 {
        smiv2:display-hint "d";
        range "1..2147483647";
      }
      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.";
    }

    typedef InterfaceIndexOrZero {
      type int32 {
        smiv2:display-hint "d";
        range "0..2147483647";
      }
      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.";
    }

    container IF-MIB {
      config false;
      container interfaces {
        smiv2:oid "1.3.6.1.2.1.2";
        leaf ifNumber {
          smiv2:max-access "read-only";
          smiv2:oid "1.3.6.1.2.1.2.1";
          type int32;
          description
            "The number of network interfaces (regardless of their
current state) present on this system.";
        }
      }  // container interfaces

      container ifMIBObjects {
        smiv2:oid "1.3.6.1.2.1.31.1";
        leaf ifTableLastChange {
          smiv2:max-access "read-only";
          smiv2:oid "1.3.6.1.2.1.31.1.5";
          type yang:timeticks;
          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.";
        }

        leaf ifStackLastChange {
          smiv2:max-access "read-only";
          smiv2:oid "1.3.6.1.2.1.31.1.6";
          type yang:timeticks;
          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.";
        }
      }  // container ifMIBObjects

      container ifTable {
        smiv2:oid "1.3.6.1.2.1.2.2";
        description
          "A list of interface entries.  The number of entries is
given by the value of ifNumber.";
        list ifEntry {
          smiv2:oid "1.3.6.1.2.1.2.2.1";
          key "ifIndex";
          description
            "An entry containing management information applicable to a
particular interface.";
          leaf ifIndex {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.1";
            type InterfaceIndex;
            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.";
          }

          leaf ifDescr {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.2";
            type snmpv2-tc:DisplayString {
              length "0..255";
            }
            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.";
          }

          leaf ifType {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.3";
            type ianaiftype-mib:IANAifType;
            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.";
          }

          leaf ifMtu {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.4";
            type int32;
            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.";
          }

          leaf ifSpeed {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.5";
            type yang:gauge32;
            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.";
          }

          leaf ifPhysAddress {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.6";
            type yang:phys-address;
            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.";
          }

          leaf ifAdminStatus {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.2.2.1.7";
            type enumeration {
              enum "up" {
                value 1;
              }
              enum "down" {
                value 2;
              }
              enum "testing" {
                value 3;
              }
            }
            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).";
          }

          leaf ifOperStatus {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.8";
            type enumeration {
              enum "up" {
                value 1;
              }
              enum "down" {
                value 2;
              }
              enum "testing" {
                value 3;
              }
              enum "unknown" {
                value 4;
              }
              enum "dormant" {
                value 5;
              }
              enum "notPresent" {
                value 6;
              }
              enum "lowerLayerDown" {
                value 7;
              }
            }
            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.";
          }

          leaf ifLastChange {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.9";
            type yang:timeticks;
            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.";
          }

          leaf ifInOctets {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.10";
            type yang:counter32;
            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.";
          }

          leaf ifInUcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.11";
            type yang:counter32;
            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.";
          }

          leaf ifInNUcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.12";
            type yang:counter32;
            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.";
          }

          leaf ifInDiscards {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.13";
            type yang:counter32;
            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.";
          }

          leaf ifInErrors {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.14";
            type yang:counter32;
            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.";
          }

          leaf ifInUnknownProtos {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.15";
            type yang:counter32;
            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.";
          }

          leaf ifOutOctets {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.16";
            type yang:counter32;
            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.";
          }

          leaf ifOutUcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.17";
            type yang:counter32;
            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.";
          }

          leaf ifOutNUcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.18";
            type yang:counter32;
            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.";
          }

          leaf ifOutDiscards {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.19";
            type yang:counter32;
            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.";
          }

          leaf ifOutErrors {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.20";
            type yang:counter32;
            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.";
          }

          leaf ifOutQLen {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.21";
            type yang:gauge32;
            status deprecated;
            description
              "The length of the output packet queue (in packets).";
          }

          leaf ifSpecific {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.2.2.1.22";
            type yang:object-identifier-128;
            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 RFC 2579.  In fact, it is
recommended that the media-specific MIB specify what value
ifSpecific should/can take for values of ifType.  If no MIB
definitions specific to the particular media are available,
the value should be set to the OBJECT IDENTIFIER { 0 0 }.";
          }

          leaf ifName {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.1";
            type snmpv2-tc:DisplayString;
            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.";
          }

          leaf ifInMulticastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.2";
            type yang:counter32;
            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.";
          }

          leaf ifInBroadcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.3";
            type yang:counter32;
            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.";
          }

          leaf ifOutMulticastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.4";
            type yang:counter32;
            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.";
          }

          leaf ifOutBroadcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.5";
            type yang:counter32;
            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.";
          }

          leaf ifHCInOctets {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.6";
            type yang:counter64;
            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.";
          }

          leaf ifHCInUcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.7";
            type yang:counter64;
            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.";
          }

          leaf ifHCInMulticastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.8";
            type yang:counter64;
            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.";
          }

          leaf ifHCInBroadcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.9";
            type yang:counter64;
            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.";
          }

          leaf ifHCOutOctets {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.10";
            type yang:counter64;
            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.";
          }

          leaf ifHCOutUcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.11";
            type yang:counter64;
            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.";
          }

          leaf ifHCOutMulticastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.12";
            type yang:counter64;
            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.";
          }

          leaf ifHCOutBroadcastPkts {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.13";
            type yang:counter64;
            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.";
          }

          leaf ifLinkUpDownTrapEnable {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.14";
            type enumeration {
              enum "enabled" {
                value 1;
              }
              enum "disabled" {
                value 2;
              }
            }
            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.";
          }

          leaf ifHighSpeed {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.15";
            type yang:gauge32;
            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.";
          }

          leaf ifPromiscuousMode {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.16";
            type boolean;
            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.";
          }

          leaf ifConnectorPresent {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.17";
            type boolean;
            description
              "This object has the value 'true(1)' if the interface
sublayer has a physical connector and the value 'false(2)'
otherwise.";
          }

          leaf ifAlias {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.18";
            type snmpv2-tc:DisplayString {
              length "0..64";
            }
            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.";
          }

          leaf ifCounterDiscontinuityTime {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.1.1.19";
            type yang:timestamp;
            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.";
          }

          leaf ifTestId {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.3.1.1";
            type snmpv2-tc:TestAndIncr;
            status deprecated;
            description
              "This object identifies the current invocation of the
interface's test.";
          }

          leaf ifTestStatus {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.3.1.2";
            type enumeration {
              enum "notInUse" {
                value 1;
              }
              enum "inUse" {
                value 2;
              }
            }
            status deprecated;
            description
              "This object indicates whether or not some manager currently
has the necessary 'ownership' required to invoke a test on
this interface.  A write to this object is only successful
when it changes its value from 'notInUse(1)' to 'inUse(2)'.
After completion of a test, the agent resets the value back
to 'notInUse(1)'.";
          }

          leaf ifTestType {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.3.1.3";
            type snmpv2-tc:AutonomousType;
            status deprecated;
            description
              "A control variable used to start and stop operator-
initiated interface tests.  Most OBJECT IDENTIFIER values
assigned to tests are defined elsewhere, in association with
specific types of interface.  However, this document assigns
a value for a full-duplex loopback test, and defines the
special meanings of the subject identifier:

    noTest  OBJECT IDENTIFIER ::= { 0 0 }

When the value noTest is written to this object, no action
is taken unless a test is in progress, in which case the
test is aborted.  Writing any other value to this object is
only valid when no test is currently in progress, in which
case the indicated test is initiated.

When read, this object always returns the most recent value
that ifTestType was set to.  If it has not been set since
the last initialization of the network management subsystem
on the agent, a value of noTest is returned.";
          }

          leaf ifTestResult {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.3.1.4";
            type enumeration {
              enum "none" {
                value 1;
              }
              enum "success" {
                value 2;
              }
              enum "inProgress" {
                value 3;
              }
              enum "notSupported" {
                value 4;
              }
              enum "unAbleToRun" {
                value 5;
              }
              enum "aborted" {
                value 6;
              }
              enum "failed" {
                value 7;
              }
            }
            status deprecated;
            description
              "This object contains the result of the most recently
requested test, or the value none(1) if no tests have been
requested since the last reset.  Note that this facility
provides no provision for saving the results of one test
when starting another, as could be required if used by
multiple managers concurrently.";
          }

          leaf ifTestCode {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.2.1.31.1.3.1.5";
            type yang:object-identifier-128;
            status deprecated;
            description
              "This object contains a code which contains more specific
information on the test result, for example an error-code
after a failed test.  Error codes and other values this
object may take are specific to the type of interface and/or
test.  The value may have the semantics of either the
AutonomousType or InstancePointer textual conventions as
defined in RFC 2579.  The identifier:

    testCodeUnknown  OBJECT IDENTIFIER ::= { 0 0 }

is defined for use if no additional result code is
available.";
          }

          leaf ifTestOwner {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.3.1.6";
            type OwnerString;
            status deprecated;
            description
              "The entity which currently has the 'ownership' required to
invoke a test on this interface.";
          }
        }  // list ifEntry
      }  // container ifTable

      container ifStackTable {
        smiv2:oid "1.3.6.1.2.1.31.1.2";
        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 ";
        list ifStackEntry {
          smiv2:oid "1.3.6.1.2.1.31.1.2.1";
          key "ifStackHigherLayer ifStackLowerLayer";
          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.";
          leaf ifStackHigherLayer {
            smiv2:max-access "not-accessible";
            smiv2:oid "1.3.6.1.2.1.31.1.2.1.1";
            type InterfaceIndexOrZero;
            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.";
          }

          leaf ifStackLowerLayer {
            smiv2:max-access "not-accessible";
            smiv2:oid "1.3.6.1.2.1.31.1.2.1.2";
            type InterfaceIndexOrZero;
            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.";
          }

          leaf ifStackStatus {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.2.1.3";
            type snmpv2-tc:RowStatus;
            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.";
          }
        }  // list ifStackEntry
      }  // container ifStackTable

      container ifRcvAddressTable {
        smiv2:oid "1.3.6.1.2.1.31.1.4";
        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
required, for the address which has the functional address
bit ANDed with the bit mask of all functional addresses for
which the interface will accept frames.

A system is normally able to use any unicast address which
corresponds to an entry in this table as a source address.";
        list ifRcvAddressEntry {
          smiv2:oid "1.3.6.1.2.1.31.1.4.1";
          key "ifIndex ifRcvAddressAddress";
          description
            "A list of objects identifying an address for which the
system will accept packets/frames on the particular
interface identified by the index value ifIndex.";
          leaf ifIndex {
            type leafref {
              path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifIndex";
            }
          }

          leaf ifRcvAddressAddress {
            smiv2:max-access "not-accessible";
            smiv2:oid "1.3.6.1.2.1.31.1.4.1.1";
            type yang:phys-address;
            description
              "An address for which the system will accept packets/frames
on this entry's interface.";
          }

          leaf ifRcvAddressStatus {
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.4.1.2";
            type snmpv2-tc:RowStatus;
            description
              "This object is used to create and delete rows in the
ifRcvAddressTable.";
          }

          leaf ifRcvAddressType {
            smiv2:defval "volatile";
            smiv2:max-access "read-write";
            smiv2:oid "1.3.6.1.2.1.31.1.4.1.3";
            type enumeration {
              enum "other" {
                value 1;
              }
              enum "volatile" {
                value 2;
              }
              enum "nonVolatile" {
                value 3;
              }
            }
            description
              "This object has the value nonVolatile(3) for those entries
in the table which are valid and will not be deleted by the
next restart of the managed system.  Entries having the
value volatile(2) are valid and exist, but have not been
saved, so that will not exist after the next restart of the
managed system.  Entries having the value other(1) are valid
and exist but are not classified as to whether they will
continue to exist after the next restart.";
          }
        }  // list ifRcvAddressEntry
      }  // container ifRcvAddressTable
    }  // container IF-MIB

    notification linkDown {
      smiv2:oid "1.3.6.1.6.3.1.1.5.3";
      description
        "A linkDown trap signifies that the SNMP entity, acting in
an agent role, has detected that the ifOperStatus object for
one of its communication links is about to enter the down
state from some other state (but not from the notPresent
state).  This other state is indicated by the included value
of ifOperStatus.";
      container object-1 {
        leaf ifIndex {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifIndex";
          }
        }
      }  // container object-1

      container object-2 {
        leaf ifIndex {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifIndex";
          }
        }

        leaf ifAdminStatus {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifAdminStatus";
          }
        }
      }  // container object-2

      container object-3 {
        leaf ifIndex {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifIndex";
          }
        }

        leaf ifOperStatus {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifOperStatus";
          }
        }
      }  // container object-3
    }  // notification linkDown

    notification linkUp {
      smiv2:oid "1.3.6.1.6.3.1.1.5.4";
      description
        "A linkUp trap signifies that the SNMP entity, acting in an
agent role, has detected that the ifOperStatus object for
one of its communication links left the down state and
transitioned into some other state (but not into the
notPresent state).  This other state is indicated by the
included value of ifOperStatus.";
      container object-1 {
        leaf ifIndex {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifIndex";
          }
        }
      }  // container object-1

      container object-2 {
        leaf ifIndex {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifIndex";
          }
        }

        leaf ifAdminStatus {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifAdminStatus";
          }
        }
      }  // container object-2

      container object-3 {
        leaf ifIndex {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifIndex";
          }
        }

        leaf ifOperStatus {
          type leafref {
            path "/IF-MIB:IF-MIB/IF-MIB:ifTable/IF-MIB:ifEntry/IF-MIB:ifOperStatus";
          }
        }
      }  // container object-3
    }  // notification linkUp
  }  // module IF-MIB