module CISCO-IP-URPF-MIB {

    yang-version 1;

    namespace
      "urn:ietf:params:xml:ns:yang:smiv2:CISCO-IP-URPF-MIB";

    prefix CISCO-IP-URPF-MIB;

    import IF-MIB {
      prefix if-mib;
    }
    import SNMP-FRAMEWORK-MIB {
      prefix snmp-framework;
    }
    import ietf-yang-smiv2 {
      prefix smiv2;
    }
    import ietf-yang-types {
      prefix yang;
    }

    organization "Cisco System, Inc.";

    contact
      "Postal: Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
USA

Tel: +1 800 553-NETS

E-mail: cs-cef@cisco.com";

    description
      "Unicast Reverse Path Forwarding (URPF) is a function that
checks the validity of the source address of IP packets
received on an interface. This in an attempt to prevent
Denial of Service attacks based on IP address spoofing.

URPF checks validity of a source address by determining
whether the packet would be successfully routed as a
destination address.
Based on configuration, the check made
can be for existence of any route for the address, or more
strictly for a route out the interface on which the packet
was received by the device. When a violating packet is
detected, it can be dropped.
This MIB allows detection of
spoofingevents.";

    revision "2011-12-29" {
      description
        "2 New TC are defined to support Dynamic template MIB";
    }

    revision "2004-11-12" {
      description
        "Initial version of this MIB module.";
    }

    smiv2:alias "cipUrpfIfConfTable" {
      description "This table contains statistics information on URPF on
an interface.";
      smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1";
    }
    smiv2:alias "cipUrpfIfConfEntry" {
      description "A row exists in this table if a row exists
in cipUrpfIfMonTable.";
      smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1.1";
    }
    smiv2:alias "ciscoIpUrpfMIB" {
      smiv2:oid "1.3.6.1.4.1.9.9.451";
    }
    smiv2:alias "ciscoIpUrpfMIBNotifs" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.0";
    }
    smiv2:alias "ciscoIpUrpfMIBObjects" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.1";
    }
    smiv2:alias "cipUrpfScalar" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.1.1";
    }
    smiv2:alias "cipUrpfStatistics" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.1.2";
    }
    smiv2:alias "cipUrpfInterfaceConfig" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.1.3";
    }
    smiv2:alias "cipUrpfVrf" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.1.4";
    }
    smiv2:alias "ciscoIpUrpfMIBConformance" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.2";
    }
    smiv2:alias "ciscoIpUrpfMIBCompliances" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.2.1";
    }
    smiv2:alias "ciscoIpUrpfMIBGroups" {
      smiv2:oid "1.3.6.1.4.1.9.9.451.2.2";
    }

    typedef UnicastRpfType {
      type enumeration {
        enum "strict" {
          value 1;
        }
        enum "loose" {
          value 2;
        }
        enum "disabled" {
          value 3;
        }
      }
      description
        "An enumerated integer-value describing the type of
unicast Reverse Path Forwarding (RPF) a system applies to
traffic received on an interface. UnicastRpfTypes 'strict' and
'loose' RPF methods are defined in RFC3704.

'disabled'
    The system does not perform unicast RPF on packets received
    by the interface.

'strict'
    The system performs strict unicast RPF on packets received
    by the interface.
'loose'
    The system performs loose unicast RPF on packets received by
    the interface.";
      reference
        "RFC3704 (http://tools.ietf.org/html/rfc3704)";

    }

    typedef UnicastRpfOptions {
      type bits {
        bit allowDefault {
          position 0;
        }
        bit allowSelfPing {
          position 1;
        }
      }
      description
        "A bit string describing unicast Reverse Path Forwarding (RPF)
options:

'allowDefault'
    Allows the use of the default route for RPF verification.

'allowSelfPing'
    Allows a router to ping its own interface or interfaces.";
    }

    container CISCO-IP-URPF-MIB {
      config false;
      container cipUrpfScalar {
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.1";
        leaf cipUrpfDropRateWindow {
          smiv2:defval "300";
          smiv2:max-access "read-write";
          smiv2:oid "1.3.6.1.4.1.9.9.451.1.1.1";
          type int32 {
            range "1..600";
          }
          units "seconds";
          description
            "The window of time in the recent past over which the drop
count used in the drop rate computation is collected.
This global value applies for the computation of all URPF
rates, global and per-interface.

Once the period over which computations have been
performed exceeds cipUrpfDropRateWindow, every time a
computation is performed, the window slides up to end
at the current time and start at cipUrpfDropRateWindow
seconds before.

The cipUrpfDropRateWindow must be greater than
or equal to the interval between computations
(cipUrpfComputeInterval).

Since the agent must save the drop count values
for each compute interval in order to slide the window,
the number of counts saved is the quotient of
cipUrpfDropRateWindow divided by cipUrpfComputeInterval.";
        }

        leaf cipUrpfComputeInterval {
          smiv2:defval "30";
          smiv2:max-access "read-write";
          smiv2:oid "1.3.6.1.4.1.9.9.451.1.1.2";
          type int32 {
            range "1..120";
          }
          units "seconds";
          description
            "The time between rate computations. This global value
applies for the computation of all URPF rates, global
and per-interface.

When the value of cipUrpfComputeInterval is changed,
the interval in-progress proceeds as though the value
had not changed. The change will apply to the length
of subsequent intervals.

The cipUrpfComputeInterval must be less than or equal
to the cipUrpfDropRateWindow.";
        }

        leaf cipUrpfDropNotifyHoldDownTime {
          smiv2:defval "300";
          smiv2:max-access "read-write";
          smiv2:oid "1.3.6.1.4.1.9.9.451.1.1.3";
          type int32 {
            range "1..1000";
          }
          units "seconds";
          description
            "The minimum time between issuance of
cipUrpfIfDropRateNotify notifications for a
particular interface and packet forwarding type.

Notifications are generated for each interface and
packet forwarding type that exceeds the drop-rate.
When a Notify is sent because the drop-rate is
exceeded for a particular interface and forwarding
type, the time specified by this object is used to
specify the minimum time that must elapse before
another Notify can be sent for that interface and
forwarding type. The time is specified globally but
used individually.";
        }
      }  // container cipUrpfScalar

      container cipUrpfTable {
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.1";
        description
          "This table contains summary information for the
managed device on URPF dropping.";
        list cipUrpfEntry {
          smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.1.1";
          key "cipUrpfIpVersion";
          description
            "If the managed device supports URPF dropping,
a row exists for each IP version type (v4 and v6).
A row contains summary information on URPF
dropping over the entire managed device.";
          leaf cipUrpfIpVersion {
            smiv2:max-access "not-accessible";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.1.1.1";
            type enumeration {
              enum "ipv4" {
                value 1;
              }
              enum "ipv6" {
                value 2;
              }
            }
            description
              "Specifies the version of IP forwarding on an interface
to which the table row URPF counts, rates, and
configuration apply.";
          }

          leaf cipUrpfDrops {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.1.1.2";
            type yang:counter32;
            units "packets";
            description
              "Sum of dropped IP version cipUrpfIpVersion packets failing
a URPF check. This value is the sum of drops of packets
received on all interfaces of the managed device.";
          }

          leaf cipUrpfDropRate {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.1.1.3";
            type yang:gauge32;
            units "packets per second";
            description
              "The rate of packet drops of IP version cipUrpfIpVersion
packets due to URPF for the managed device. The
per-interface drop rate notification is issued on rates
exceeding a limit (rising rate). This dropping may indicate
an security attack on the network. To determine whether the
attack/event is over, the NMS must consult the managed
device. This object can be polled to determine the recent
drop rate for the managed device as a whole, in addition to
querying particular interface objects.
This object is the
average rate of dropping over the most recent window of
time. The rate is computed by dividing the number of packets
dropped over a window by the window time in seconds. The
window time is specified by cipUrpfDropRateWindow. Each time
the drop rate is computed, and at system startup, a snapshot
is taken of the latest value of cipUrpfDrops. Subtracting
from this the snapshot of cipUrpfDrops at the start of the
current window of time gives the number of packets dropped.
The drop rate is computed every cipUrpfComputeInterval
seconds. As an example, let cipUrpfDropRateWindow be 300
seconds, and cipUrpfComputeInterval 30 seconds. Every 30
seconds, the drop count five minutes previous is subtracted
from the current drop count, and the result is divided by
300 to arrive at the drop rate.
At device start-up, until
the device has been up more than cipUrpfDropRateWindow, when
drop rate is computed, the value of cipUrpfDrops is divided
by the time the device has been up.
After the device has
been up for cipUrpfDropRateWindow, when drop rate is
computed, the number of packet drops counted from interval
start time to the computation time is divided by
cipUrpfDropRateWindow.
Changes to cipUrpfDropRateWindow are
not reflected in this object until the next computation
time.
The rate from the most recent computation is the
value fetched until the subsequent computation is
performed.";
          }
        }  // list cipUrpfEntry
      }  // container cipUrpfTable

      container cipUrpfIfMonTable {
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.2";
        description
          "This table contains information on URPF dropping on
an interface.";
        list cipUrpfIfMonEntry {
          smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.2.1";
          key "ifIndex cipUrpfIfIpVersion";
          description
            "If IPv4 packet forwarding is configured on an interface,
and is configured to perform URPF checking, a row appears
in this table with indices [ifIndex][ipv4]. If IPv4
packet forwarding is deconfigured, or URPF checking
is deconfigured, the row disappears.

If IPv6 packet forwarding is configured on an interface,
and is configured to perform URPF checking, a row appears
in the table with indices [ifIndex][ipv6].  If IPv6
packet forwarding is deconfigured, or URPF checking
is deconfigured, the row disappears.";
          leaf ifIndex {
            type leafref {
              path "/if-mib:IF-MIB/if-mib:ifTable/if-mib:ifEntry/if-mib:ifIndex";
            }
          }

          leaf cipUrpfIfIpVersion {
            smiv2:max-access "not-accessible";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.2.1.1";
            type enumeration {
              enum "ipv4" {
                value 1;
              }
              enum "ipv6" {
                value 2;
              }
            }
            description
              "Specifies the version of IP forwarding on an interface
to which the table row URPF counts, rates, and
configuration apply.";
          }

          leaf cipUrpfIfDrops {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.2.1.2";
            type yang:counter32;
            units "packets";
            description
              "The number of IP packets of version cipUrpfIfIpVersion
failing the URPF check and dropped by the managed device
on a particular interface.

Discontinuities in the value of this variable can occur
at re-initialization of the management system, and at
other times as indicated by the values of
cipUrpfIfDiscontinuityTime.";
          }

          leaf cipUrpfIfSuppressedDrops {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.2.1.3";
            type yang:counter32;
            units "packets";
            description
              "The number of IP packets of version cipUrpfIfIpVersion
failing the URPF check but given a reprieve and not
dropped by the managed device. Depending on the
device configuration and capabilities, the following
cases may cause incrementing of the counter:
- if the managed device is configured to allow self-pings
  and the managed device pings itself.
- if the managed device is configured for loose URPF (if any
  interface has a route to the source), and the strict
  case fails while the loose case passes.
- DHCP Request packets (src 0.0.0.0 dst 255.255.255.255)
  will pass after initially being marked for drop.
- RIP routing on unnumbered interfaces will pass after
  initially being marked for drop.
- multicast packets will pass after initially being marked
  for drop
- ACL's can be applied to permit packets after initially
  being marked for drop.

Discontinuities in the value of this variable can occur
at re-initialization of the management system, and at
other times as indicated by the values of
cipUrpfIfDiscontinuityTime.";
          }

          leaf cipUrpfIfDropRate {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.2.1.4";
            type yang:gauge32;
            units "packets/second";
            description
              "The rate of packet drops of IP version cipUrpfIfIpVersion
packets due to URPF on the interface.

This object is the average rate of dropping over the most
recent interval of time. The rate is computed by dividing
the number of packets dropped over an interval by the
interval time in seconds. Each time the drop rate
is computed, and at system startup, a snapshot is taken
of the latest value of cipUrpfIfDrops. Subtracting from this
the snapshot of cipUrpfIfDrops at the start of the current
interval of time gives the number of packets dropped.
The drop rate is computed every cipUrpfComputeInterval
seconds.

When drop rate is computed, if time since the creation of
a row in cipUrpfIfMonTable is less than
cipUrpfDropRateWindow, the value of cipUrpfIfDrops is
divided by the time since row was created.

After the row has been in existence for
cipUrpfDropRateWindow, when drop rate is computed, the
number of packet drops counted on the interface from
interval start time to the computation time is divided
by cipUrpfDropRateWindow.

Changes to cipUrpfDropRateWindow are not reflected in this
object until the next computation time.

The rate from the  most recent computation is the value
fetched until the subsequent computation is performed.";
          }

          leaf cipUrpfIfDiscontinuityTime {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.2.1.5";
            type yang:timestamp;
            description
              "The value of sysUpTime on the most recent
occasion at which this interface's  counters
suffered  a discontinuity.
If no such discontinuities have occurred
since the last re-initialization of the
local management subsystem, then this
object contains a value of zero.";
          }
        }  // list cipUrpfIfMonEntry
      }  // container cipUrpfIfMonTable

      container cipUrpfVrfIfTable {
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.3";
        description
          "This table contains statistics information for interfaces
performing URPF using VRF table to determine reachability.";
        list cipUrpfVrfIfEntry {
          smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.3.1";
          key "cipUrpfVrfName ifIndex";
          description
            "An entry exists for a VRF and interface if and only
if the VRF associated with the interface is configured
to perform IP URPF checking using the routing
table for the VRF.";
          leaf cipUrpfVrfName {
            type leafref {
              path "/CISCO-IP-URPF-MIB:CISCO-IP-URPF-MIB/CISCO-IP-URPF-MIB:cipUrpfVrfTable/CISCO-IP-URPF-MIB:cipUrpfVrfEntry/CISCO-IP-URPF-MIB:cipUrpfVrfName";
            }
          }

          leaf ifIndex {
            type leafref {
              path "/if-mib:IF-MIB/if-mib:ifTable/if-mib:ifEntry/if-mib:ifIndex";
            }
          }

          leaf cipUrpfVrfIfDrops {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.3.1.2";
            type yang:counter32;
            units "packets";
            description
              "The number of packets failing the URPF check for a VRF on
the interface and dropped by the managed device.

Discontinuities in the value of this variable can occur
at re-initialization of the management system, and at
other times as indicated by the values of
cipUrpfVrfIfDiscontinuityTime.";
          }

          leaf cipUrpfVrfIfDiscontinuityTime {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.2.3.1.3";
            type yang:timestamp;
            description
              "The value of sysUpTime on the most recent occasion at
which the URPF counters for this VRF on this interface
suffered  a discontinuity.  If no such discontinuities
have occurred since the last re-initialization of the
local management subsystem, then this object contains a
value of zero.";
          }
        }  // list cipUrpfVrfIfEntry
      }  // container cipUrpfVrfIfTable

      container cipUrpfVrfTable {
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.4.1";
        description
          "This table enables indexing URPF drop statistics
by Virtual Routing and Forwarding instances.";
        list cipUrpfVrfEntry {
          smiv2:oid "1.3.6.1.4.1.9.9.451.1.4.1.1";
          key "cipUrpfVrfName";
          description
            "An entry exists for a VRF if and only if the VRF
is associated with an interface that is configured
to perform IP URPF checking using the routing table
for that VRF.";
          leaf cipUrpfVrfName {
            smiv2:max-access "read-only";
            smiv2:oid "1.3.6.1.4.1.9.9.451.1.4.1.1.1";
            type snmp-framework:SnmpAdminString {
              length "0..32";
            }
            description
              "This field is used to specify the VRF Table
name.";
          }
        }  // list cipUrpfVrfEntry
      }  // container cipUrpfVrfTable
    }  // container CISCO-IP-URPF-MIB

    augment /CISCO-IP-URPF-MIB:CISCO-IP-URPF-MIB/CISCO-IP-URPF-MIB:cipUrpfIfMonTable/CISCO-IP-URPF-MIB:cipUrpfIfMonEntry {
      smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1.1";
      description
        "A row exists in this table if a row exists
in cipUrpfIfMonTable.";
      leaf cipUrpfIfDropRateNotifyEnable {
        smiv2:defval "false";
        smiv2:max-access "read-write";
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1.1.1";
        type boolean;
        description
          "This object specifies whether the system produces the
cipUrpfIfDropRateNotify notification as a result of URPF
dropping of version cipUrpfIfIpVersion IP packets on this
interface. A false value prevents such notifications from
being generated by this system.";
      }

      leaf cipUrpfIfNotifyDropRateThreshold {
        smiv2:defval "1000";
        smiv2:max-access "read-write";
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1.1.2";
        type uint32;
        units "packets/second";
        description
          "When the calculated rate of URPF packet drops
(cipUrpfIfDropRate) meets or exceeds the value
specified by this object, a cipUrpfIfDropRateNotify
notification is sent if cipUrpfIfDropRateNotifyEnable
is set to true, and no such notification for the
IP version has been sent for this interface for the
hold-down period.

Note that due to the calculation used for drop rate,
if there are less than n drop events in an n-second
period the notification will not be generated. To allow
for the detection of a small number of drop events, the
value 0 (zero) is used to indicate that if any drop events
occur during the interval, a notification is generated.";
      }

      leaf cipUrpfIfNotifyDrHoldDownReset {
        smiv2:defval "false";
        smiv2:max-access "read-write";
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1.1.3";
        type boolean;
        description
          "Setting this object to true causes the five-minute
hold-down timer for emitting URPF drop rate
notifications for IP version cipUrpfIfIpVersion on
the interface to be short-circuited.  If a notification
is due and would be emitted for the interface if the
five-minutes elapsed, setting this object will cause
the notification to be sent.

This is a trigger, and doesn't hold information. It is
set and an action is performed. Therefore a get for
this object always returns false.";
      }

      leaf cipUrpfIfCheckStrict {
        smiv2:max-access "read-only";
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1.1.4";
        type enumeration {
          enum "strict" {
            value 1;
          }
          enum "loose" {
            value 2;
          }
        }
        description
          "Interface configuration indicating the strictness of
the reachability check performed
on the interface.
- strict: check that source addr is reachable via
	  the interface it came in on.
- loose : check that source addr is reachable via
	  some interface on the device.";
      }

      leaf cipUrpfIfWhichRouteTableID {
        smiv2:max-access "read-only";
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1.1.5";
        type enumeration {
          enum "default" {
            value 1;
          }
          enum "vrf" {
            value 2;
          }
        }
        description
          "Interface configuration indicating the routing table
consulted for the reachability check:
- default: the non-private routing table for of the
	   managed system.
- vrf   : a particular VPN routing table.";
      }

      leaf cipUrpfIfVrfName {
        smiv2:max-access "read-only";
        smiv2:oid "1.3.6.1.4.1.9.9.451.1.3.1.1.6";
        type snmp-framework:SnmpAdminString {
          length "0..32";
        }
        description
          "If the value of cipUrpfIfWhichRouteTableID is 'vrf',
the name of the VRF Table. Otherwise a zero-length
string.";
      }
    }

    notification cipUrpfIfDropRateNotify {
      smiv2:oid "1.3.6.1.4.1.9.9.451.0.1";
      description
        "This notification is generated when
cipUrpfIfDropRateNotifyEnable is set to true and
the calculated URPF drop rate (cipUrpfIfDropRate)
exceeds the notification threshold drop rate
(cipUrpfIfNotifyDropRateThreshold). Note the
exceptional value of 0 for threshold allows notification
generation if any drop events occur in an interval.

After generating this notification, another such
notification will not be sent out for a minimum of five
minutes (note the exception to this provided by
cipUrpfIfNotifyDrHoldDownReset).

The object value present in the notification is the
the drop rate that exceeded the threshold.";
      container object-1 {
        leaf ifIndex {
          type leafref {
            path "/if-mib:IF-MIB/if-mib:ifTable/if-mib:ifEntry/if-mib:ifIndex";
          }
        }

        leaf cipUrpfIfIpVersion {
          type leafref {
            path "/CISCO-IP-URPF-MIB:CISCO-IP-URPF-MIB/CISCO-IP-URPF-MIB:cipUrpfIfMonTable/CISCO-IP-URPF-MIB:cipUrpfIfMonEntry/CISCO-IP-URPF-MIB:cipUrpfIfIpVersion";
          }
        }

        leaf cipUrpfIfDropRate {
          type leafref {
            path "/CISCO-IP-URPF-MIB:CISCO-IP-URPF-MIB/CISCO-IP-URPF-MIB:cipUrpfIfMonTable/CISCO-IP-URPF-MIB:cipUrpfIfMonEntry/CISCO-IP-URPF-MIB:cipUrpfIfDropRate";
          }
        }
      }  // container object-1
    }  // notification cipUrpfIfDropRateNotify
  }  // module CISCO-IP-URPF-MIB