-- ****************************************************************** -- FS-URPF-MIB.mib -- -- This module is used for monitoring the state of Unicast Reverse -- Path Forwarding (URPF) checking. -- -- April 2009, huangcb -- -- Copyright (c) 2009 by FS.COM Inc.. -- All rights reserved. -- ****************************************************************** -- FS-URPF-MIB DEFINITIONS ::= BEGIN IMPORTS MODULE-IDENTITY, OBJECT-TYPE, Gauge32, Integer32, Counter32, Unsigned32, NOTIFICATION-TYPE FROM SNMPv2-SMI MODULE-COMPLIANCE, NOTIFICATION-GROUP, OBJECT-GROUP FROM SNMPv2-CONF TruthValue FROM SNMPv2-TC SnmpAdminString FROM SNMP-FRAMEWORK-MIB ifIndex FROM IF-MIB fsMgmt FROM FS-SMI; fsUrpfMIB MODULE-IDENTITY LAST-UPDATED "200904090000z" ORGANIZATION "FS.COM Inc.." CONTACT-INFO " Tel: 400-865-2852 E-mail: https://www.fs.com/live_chat_service_mail.html" 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 spoofing events." REVISION "200904090000z" DESCRIPTION "Initial version of this MIB module." ::= { fsMgmt 46 } -- -- URPF MIB -- fsUrpfMIBObjects OBJECT IDENTIFIER ::= { fsUrpfMIB 0 } fsUrpfMIBNotifs OBJECT IDENTIFIER ::= { fsUrpfMIB 1 } fsUrpfMIBConformance OBJECT IDENTIFIER ::= { fsUrpfMIB 2 } -- -- URPF MIB Objects -- fsUrpfScalar OBJECT IDENTIFIER ::= { fsUrpfMIBObjects 1 } fsUrpfStatistics OBJECT IDENTIFIER ::= { fsUrpfMIBObjects 2 } fsUrpfInterfaceConfig OBJECT IDENTIFIER ::= { fsUrpfMIBObjects 3 } -- -- fsUrpfScalar -- fsUrpfComputeInterval OBJECT-TYPE SYNTAX Integer32 (30..300) UNITS "seconds" MAX-ACCESS read-write STATUS current 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 fsUrpfComputeInterval 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 fsUrpfComputeInterval must be less than or equal to the fsUrpfDropRateWindow. Relation CLI: ip verify urpf drop-rate compute interval seconds." DEFVAL { 30 } ::= { fsUrpfScalar 1 } fsUrpfDropRateWindow OBJECT-TYPE SYNTAX Integer32 (150..1500) UNITS "seconds" MAX-ACCESS read-only STATUS current 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 fsUrpfDropRateWindow, every time a computation is performed, the window slides up to end at the current time and start at fsUrpfDropRateWindow seconds before. 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 fsUrpfDropRateWindow divided by fsUrpfComputeInterval." DEFVAL { 150 } ::= { fsUrpfScalar 2 } fsUrpfDropNotifyHoldDownTime OBJECT-TYPE SYNTAX Integer32(30..300) UNITS "seconds" MAX-ACCESS read-write STATUS current DESCRIPTION "The minimum time between issuance of fsUrpfIfDropRateNotify 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. Relation CLI: ip verify urpf drop-rate notify hold-down seconds." DEFVAL { 300 } ::= { fsUrpfScalar 3 } -- -- fsUrpfStatistics -- fsUrpfTable OBJECT-TYPE SYNTAX SEQUENCE OF FSUrpfEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains summary information for the managed device on URPF dropping." ::= { fsUrpfStatistics 1 } fsUrpfEntry OBJECT-TYPE SYNTAX FSUrpfEntry MAX-ACCESS not-accessible STATUS current 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." INDEX { fsUrpfIpVersion } ::= { fsUrpfTable 1 } FSUrpfEntry ::= SEQUENCE { fsUrpfIpVersion INTEGER, fsUrpfDrops Counter32, fsUrpfDropRate Gauge32 } fsUrpfIpVersion OBJECT-TYPE SYNTAX INTEGER {ipv4(1), ipv6(2)} MAX-ACCESS not-accessible STATUS current DESCRIPTION "Specifies the version of IP forwarding on an interface to which the table row URPF counts, rates, and configuration apply." ::= { fsUrpfEntry 1 } fsUrpfDrops OBJECT-TYPE SYNTAX Counter32 UNITS "packets" MAX-ACCESS read-only STATUS current DESCRIPTION "Sum of dropped IP version fsUrpfIpVersion packets failing a URPF check. This value is the sum of drops of packets received on all interfaces of the managed device." ::= { fsUrpfEntry 2 } fsUrpfDropRate OBJECT-TYPE SYNTAX Gauge32 UNITS "packets per second" MAX-ACCESS read-only STATUS current DESCRIPTION "The rate of packet drops of IP version fsUrpfIpVersion 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 fsUrpfDropRateWindow. Each time the drop rate is computed, and at system startup, a snapshot is taken of the latest value of fsUrpfDrops. Subtracting from this the snapshot of fsUrpfDrops at the start of the current window of time gives the number of packets dropped. The drop rate is computed every fsUrpfComputeInterval seconds. As an example, let fsUrpfDropRateWindow be 300 seconds, and fsUrpfComputeInterval 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 fsUrpfDropRateWindow, when drop rate is computed, the value of fsUrpfDrops is divided by the time the device has been up. After the device has been up for fsUrpfDropRateWindow, when drop rate is computed, the number of packet drops counted from interval start time to the computation time is divided by fsUrpfDropRateWindow. Changes to fsUrpfDropRateWindow 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." ::= { fsUrpfEntry 3 } fsUrpfIfMonTable OBJECT-TYPE SYNTAX SEQUENCE OF FSUrpfIfMonEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains information on URPF dropping on an interface." ::= { fsUrpfStatistics 2 } fsUrpfIfMonEntry OBJECT-TYPE SYNTAX FSUrpfIfMonEntry MAX-ACCESS not-accessible STATUS current 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." INDEX { ifIndex, fsUrpfIfIpVersion } ::= { fsUrpfIfMonTable 1 } FSUrpfIfMonEntry ::= SEQUENCE { fsUrpfIfIpVersion INTEGER, fsUrpfIfDrops Counter32, fsUrpfIfDropRate Gauge32 } fsUrpfIfIpVersion OBJECT-TYPE SYNTAX INTEGER {ipv4(1), ipv6(2)} MAX-ACCESS not-accessible STATUS current DESCRIPTION "Specifies the version of IP forwarding on an interface to which the table row URPF counts, rates, and configuration apply." ::= { fsUrpfIfMonEntry 1} fsUrpfIfDrops OBJECT-TYPE SYNTAX Counter32 UNITS "packets" MAX-ACCESS read-only STATUS current DESCRIPTION "The number of IP packets of version fsUrpfIfIpVersion failing the URPF check and dropped by the managed device on a particular interface." ::= { fsUrpfIfMonEntry 2 } fsUrpfIfDropRate OBJECT-TYPE SYNTAX Gauge32 UNITS "packets/second" MAX-ACCESS read-only STATUS current DESCRIPTION "The rate of packet drops of IP version fsUrpfIfIpVersion 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 fsUrpfIfDrops. Subtracting from this the snapshot of fsUrpfIfDrops at the start of the current interval of time gives the number of packets dropped. The drop rate is computed every fsUrpfComputeInterval seconds. When drop rate is computed, if time since the creation of a row in fsUrpfIfMonTable is less than fsUrpfDropRateWindow, the value of fsUrpfIfDrops is divided by the time since row was created. After the row has been in existence for fsUrpfDropRateWindow, 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 fsUrpfDropRateWindow. Changes to fsUrpfDropRateWindow 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." ::= { fsUrpfIfMonEntry 3 } -- -- fsUrpfInterfaceConfig -- fsUrpfIfConfTable OBJECT-TYPE SYNTAX SEQUENCE OF FSUrpfIfConfEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains statistics information on URPF on an interface." ::= { fsUrpfInterfaceConfig 1 } fsUrpfIfConfEntry OBJECT-TYPE SYNTAX FSUrpfIfConfEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A row exists in this table if a row exists in fsUrpfIfMonTable." AUGMENTS { fsUrpfIfMonEntry } ::= { fsUrpfIfConfTable 1 } FSUrpfIfConfEntry ::= SEQUENCE { fsUrpfIfCheckStrict INTEGER, fsUrpfIfDropRateNotifyEnable TruthValue, fsUrpfIfNotifyDropRateThreshold Unsigned32, fsUrpfIfNotifyDrHoldDownReset TruthValue, fsUrpfIfWhichRouteTableID INTEGER, fsUrpfIfVrfName SnmpAdminString } fsUrpfIfCheckStrict OBJECT-TYPE SYNTAX INTEGER { none(0), strict(1), loose(2) } MAX-ACCESS read-only STATUS current DESCRIPTION "Interface configuration indicating the strictness of the reachability check performed on the interface. - none: not enable urpf check in this 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." ::= { fsUrpfIfConfEntry 1 } fsUrpfIfDropRateNotifyEnable OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-write STATUS current DESCRIPTION "This object specifies whether the system produces the fsUrpfIfDropRateNotify notification as a result of URPF dropping of version fsUrpfIfIpVersion IP packets on this interface. A false value prevents such notifications from being generated by this system. Relation CLI: ip verify urpf drop-rate notify." DEFVAL { false } ::= { fsUrpfIfConfEntry 2 } fsUrpfIfNotifyDropRateThreshold OBJECT-TYPE SYNTAX Unsigned32 UNITS "packets/second" MAX-ACCESS read-write STATUS current DESCRIPTION "When the calculated rate of URPF packet drops (fsUrpfIfDropRate) meets or exceeds the value specified by this object, a fsUrpfIfDropRateNotify notification is sent if fsUrpfIfDropRateNotifyEnable 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. Relation CLI: ip verify urpf drop-rate notify hold-down seconds." DEFVAL { 1000 } ::= { fsUrpfIfConfEntry 3 } fsUrpfIfNotifyDrHoldDownReset OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-write STATUS current DESCRIPTION "Setting this object to true causes the five-minute hold-down timer for emitting URPF drop rate notifications for IP version fsUrpfIfIpVersion 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. Relation CLI: clear ip urpf interface." DEFVAL { false } ::= { fsUrpfIfConfEntry 4 } fsUrpfIfWhichRouteTableID OBJECT-TYPE SYNTAX INTEGER { default(1), vrf(2) } MAX-ACCESS read-only STATUS current 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." ::= { fsUrpfIfConfEntry 5 } fsUrpfIfVrfName OBJECT-TYPE SYNTAX SnmpAdminString (SIZE (0..32)) MAX-ACCESS read-only STATUS current DESCRIPTION "If the value of fsUrpfIfWhichRouteTableID is 'vrf', the name of the VRF Table. Otherwise a zero-length string." ::= { fsUrpfIfConfEntry 6 } -- -- URPF MIB Notifications -- fsUrpfIfDropRateNotify NOTIFICATION-TYPE OBJECTS { fsUrpfIfDropRate } STATUS current DESCRIPTION "This notification is generated when fsUrpfIfDropRateNotifyEnable is set to true and the calculated URPF drop rate (fsUrpfIfDropRate) exceeds the notification threshold drop rate (fsUrpfIfNotifyDropRateThreshold). 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 fsUrpfIfNotifyDrHoldDownReset). The object value present in the notification is the the drop rate that exceeded the threshold." ::= { fsUrpfMIBNotifs 1 } -- -- URPF MIB Conformance -- fsUrpfMIBCompliances OBJECT IDENTIFIER ::= { fsUrpfMIBConformance 1 } fsUrpfMIBGroups OBJECT IDENTIFIER ::= { fsUrpfMIBConformance 2 } fsUrpfMIBCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "An SNMP entity can implement this module to provide URPF problem diagnosis information." MODULE -- this module MANDATORY-GROUPS { fsUrpfMIBMainObjectGroup, fsUrpfMIBNotifyGroup } GROUP fsUrpfMIBVrfObjectGroup DESCRIPTION "This group is mandatory for all implementations that need to index URPF statistics by VRF interfaces." ::= { fsUrpfMIBCompliances 1 } fsUrpfMIBMainObjectGroup OBJECT-GROUP OBJECTS { fsUrpfComputeInterval, fsUrpfDropRateWindow, fsUrpfDropNotifyHoldDownTime, fsUrpfDrops, fsUrpfDropRate, fsUrpfIfDrops, fsUrpfIfDropRate, fsUrpfIfCheckStrict, fsUrpfIfDropRateNotifyEnable, fsUrpfIfNotifyDropRateThreshold, fsUrpfIfNotifyDrHoldDownReset } STATUS current DESCRIPTION "The collection of common counter objects, those needed by other objects, and the common interface table." ::= { fsUrpfMIBGroups 1 } fsUrpfMIBVrfObjectGroup OBJECT-GROUP OBJECTS { fsUrpfIfWhichRouteTableID, fsUrpfIfVrfName } STATUS current DESCRIPTION "The collection of objects needed to index by VRF." ::= { fsUrpfMIBGroups 2 } fsUrpfMIBNotifyGroup NOTIFICATION-GROUP NOTIFICATIONS { fsUrpfIfDropRateNotify } STATUS current DESCRIPTION "The collection of objects which are used to specify notifications for URPF." ::= { fsUrpfMIBGroups 3 } END