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Table Of Contents
Bidirectional Forwarding Detection MIB
Restrictions for the Bidirectional Forwarding Detection MIB
Information About the Bidirectional Forwarding Detection MIB
Capabilities Supported by the BFD MIB
Notification Generation Events
Benefits of Bidirectional Forwarding Detection MIB
Features and Technologies Related to BFD MIB
Supported Objects in the BFD MIB
VPN Aware BFD MIB Notifications
How to Configure the Bidirectional Forwarding Detection MIB
Enabling the SNMP Agent for BFD MIB Notifications
Verifying the Status of the SNMP Agent
Configuration Examples for the Bidirectional Forwarding Detection MIB
Enabling the SNMP Agent to Enable BFD Notifications: Example
Feature Information for the Bidirectional Forwarding Detection MIB
Bidirectional Forwarding Detection MIB
First Published: November 20, 2009Last Updated: June 08, 2010The Bidirectional Forwarding Detection (BFD) MIB, Version 2 feature enables Simple Network Management Protocol (SNMP) agent support in Cisco IOS software for BFD management, as implemented in the Bidirectional Forwarding Detection Management Information Base (draft-ietf-bfd-mib-02.txt). The SNMP agent code operating with the BFD MIB enables a standardized, SNMP-based approach to be used in managing the BFD features in Cisco IOS software. The BFD MIB feature introduces the CISCO-IETF-BFD-MIB. The BFD MIB is also VPN-aware, which allows SNMP to differentiate incoming packets from different VPNs.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for the Bidirectional Forwarding Detection MIB" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
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Restrictions for the Bidirectional Forwarding Detection MIB
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Restrictions for the Bidirectional Forwarding Detection MIB
The following restrictions apply to the BFD MIB for Cisco IOS releases:
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Information About the Bidirectional Forwarding Detection MIB
This section describes the following:
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BFD MIB Cisco Implementation
The BFD MIB is based on the Internet Engineering Task Force (IETF) draft MIB entitled draft-ietf-bfd-mib-02.txt which includes objects describing features that support BFD.
Slight differences between the IETF draft MIB and the implementation of the BFD capabilities within Cisco IOS software require some minor translations between the BFD MIB and the internal data structures of Cisco IOS software. These translations are made by the SNMP agent code that is installed and operating on various hosts within the network. This SNMP agent code, running in the background as a low priority process, provides a management interface to Cisco IOS software.
The SNMP objects defined in the BFD MIB can be displayed by any standard SNMP utility. All BFD MIB objects are based on the IETF draft MIB; thus, no specific Cisco SNMP application is required to support the functions and operations pertaining to the BFD MIB.
Capabilities Supported by the BFD MIB
The following functionality is supported in the BFD MIB:
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Notification Generation Events
When BFD notifications are enabled with the snmp-server enable traps bfd command with the session-up and session-down keywords, notification messages relating to specific events within Cisco IOS software are generated and sent to a specified NMS in the network.
For example, a bfdSessUp notification is sent to an NMS when BFD is configured.
Conversely, a bfdSessDown notification is generated and sent to an NMS when BFD is disabled.
Benefits of Bidirectional Forwarding Detection MIB
The BFD MIB provides the following benefits:
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Features and Technologies Related to BFD MIB
The BFD MIB feature is used in conjunction with the following features and technologies:
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Supported Objects in the BFD MIB
The BFD MIB contains numerous tables and object definitions that provide read-only SNMP management support for the BFD features in Cisco IOS software. The BFD MIB conforms to Abstract Syntax Notation One (ASN.1), thus reflecting an idealized BFD database.
Using any standard SNMP network management application, you can retrieve and display information from the BFD MIB by using GET operations; similarly, you can traverse information in the MIB database for display by using GETNEXT operations.
The BFD MIB tables and objects supported in Cisco IOS releases follow. Important MIB tables (those highlighted in bold type) are described briefly in accompanying text.
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BFD General Variables (scalars)
The following parameters apply globally to the router's BFD process:
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BFD Session Table
The BFD Session Table specifies BFD session specific information and contains the following entries:
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noDiagnostic(0),
controlDetectionTimeExpired(1),
echoFunctionFailed(2),
neighborSignaledSessionDown(3),
forwardingPlaneReset(4),
pathDown(5),
concatenatedPathDown(6),
administrativelyDown(7),
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BFD Session Performance Table
ciscoBfdSessPerfTable specifies BFD session performance counters and augments the ciscoBfdSessionTable. This table contains the following entries:
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BFD Session Mapping Table
The BFD Session Mapping Table maps the complex indexing of the BFD sessions to the flat BFDIndex used in the ciscoBfdSessionTable. If the value of the ciscoBfdSessAddr (an OID) has more that 111 sub-identifiers, then OIDs of column instances in this table have more than 128 sub-identifiers and cannot be accessed using SNMPv1, SNMPv2c, or SNMPv3. The BFD Session Mapping table contains the following entries:
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See the "MIB Walk for BFD MIB: Example" section for an example of the mapping.
Notification
Notification contains the following entries. The range mode for this notification is not supported. Therefore, only a single notification is sent for one of the ciscoBfdSessTable entries representing this session.
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VPN Aware BFD MIB
The VPN Aware BFD MIB feature enables the BFD MIB to get VPN context information. The feature adds support for different contexts for different MPLS VPNs. Users of the MIB can display BFD processes for a given MPLS VPN. The VPN Aware BFD MIB feature does not change the syntax of the BFD MIB. It changes the number and types of entries within the tables.
The BFD MIB can show information about only one context at a time. With Cisco IOS Release 12.2(33)SRE, you can specify a context using an SNMP security name.
For information about making the BFD MIB VPN-aware, see the SNMP Support over VPNs—Context-Based Access document.
SNMP Contexts
SNMP contexts provide VPN users with a secure way of accessing MIB data. When a VPN is associated with a context, that VPN's specific MIB data exists in that context. Associating a VPN with a context enables service providers to manage networks with multiple VPNs. Creating and associating a context with a VPN enables a provider to prevent the users of one VPN from accessing information about users of other VPNs on the same networking device.
VPN-aware SNMP requires that SNMP manager and agent entities operating in a VPN environment agree on mapping between the SNMP security name and the VPN name. This mapping is created by you using different contexts for the SNMP data of different VPNs, which is accomplished through the configuration of the SNMP View-based Access Control Model MIB (SNMP-VACM-MIB). The SNMP-VACM-MIB is configured with views so that a user on a VPN with a security name is allowed access to the restricted object space within the context of only that VPN.
SNMP request messages undergo three phases of security and access control before a response message is sent back with the object values within a VPN context:
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IP access lists can be configured and associated with SNMP community strings. This feature enables you to configure an association between VPN routing and forwarding (VRF) instances and SNMP community strings. When a VRF instance is associated with an SNMP community string, SNMP processes requests coming in for a particular community string only if they are received from the configured VRF. If the community string contained in the incoming packet does not have a VRF associated with it, it is processed only if it came in through a non-VRF interface.
VPN Aware BFD MIB Sessions
The VPN Aware BFD MIB feature supports an SNMP query to the BFD MIB for both global and VPN contexts. You can enter BFD queries on any VRF and on the core (global context). A query can differentiate between BFD sessions from different VPNs. BFD session information for a VPN stays in the context of that VPN. Therefore, the information from one VPN is not available to a user of a different VPN.
In an MPLS VPN, a service provider edge router (PE) might contain VRFs for several VPNs and a global routing table. To set up separate BFD processes for different VPNs on the same device, configure each VPN with a unique securityName, contextName, and View-based Access Control Model (VACM) view. The VPN securityName must be configured for the BFD MIB.
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VPN Aware BFD MIB Notifications
The VPN Aware BFD MIB feature supports BFD notifications for multiple VPN contexts for BFD. BFD notifications can be generated for the global context and for different VPNs. You can cause notifications be sent to different NMS hosts for different BFD contexts. BFD notifications associated with a specific VRF are sent to the NMS designated for that VRF. BFD global notifications are sent to the NMS configured to receive global traps.
To enable BFD context notifications for the VPN Aware BFD MIB feature, use either the SNMP ciscoBfdSessNotificationEnable object (in the global BFD context only) or the following extended global configuration commands.
To enable BFD notifications for the global context, use the following commands on a provider edge (PE) router:
Router(config)# snmp-server host host-address traps communityRouter(config)# snmp-server enable traps bfdTo enable BFD notifications for a VPN context, use the following commands:
Router(config)# snmp-server host host-address vrf vrf-name version {v1|v2c|v3} community community-string udp-port upd-port bfdRouter(config)# snmp-server enable traps bfdHow to Configure the Bidirectional Forwarding Detection MIB
This section contains the following tasks:
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Enabling the SNMP Agent for BFD MIB Notifications
The SNMP agent for the BFD MIB is disabled by default. To enable the SNMP agent for BFD MIB notifications, perform the following steps.
SUMMARY STEPS
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DETAILED STEPS
Verifying the Status of the SNMP Agent
To verify that the SNMP agent has been enabled on a host network device, perform the following steps.
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DETAILED STEPS
Examples
The follows example displays the running configuration on the target device and its SNMP information.
Router# show running-config | include snmp. . .snmp-server community public rwsnmp-server community private roAny snmp-server statement that appears in the output and takes the form shown here verifies that SNMP has been enabled on that device.
Configuration Examples for the Bidirectional Forwarding Detection MIB
This section contains the following configuration examples:
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Enabling the SNMP Agent to Enable BFD Notifications: Example
The following example shows how to enable an SNMP agent on a host network device:
Router# configure terminalRouter(config)# snmp-server community private roThe following example shows how to allow read-only access to all BFD MIB objects relating to members of access list 4 that specify the comaccess community string. No other SNMP agents will have access to any BFD MIB objects.
Router(config)# snmp-server community comaccess ro 4The following example shows how to enable a router to send BFD-related SNMP notifications or informs to an SNMP host.Router(config)# snmp-server enable traps bfdViewing BFD Sessions: Example
The following example show the output of the show bfd neighbors command, which displays BFD sessions and timers for each neighbor.
Router# show bfd neighborsNeighAddr LD/RD RH/RS State Int10.0.0.2 7/7 Up Up Et1/2.210.1.0.2 6/6 Up Up Et1/2.5DDDD::1 1/1 Up Up Et1/3Router# show bfd neighbors detailNeighAddr LD/RD RH/RS State Int10.0.0.2 9/8 Up Up Gi3/8.1Session state is UP and using echo function with 50 ms interval.OurAddr: 10.0.0.1Local Diag: 0, Demand mode: 0, Poll bit: 0MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 5Received MinRxInt: 1000000, Received Multiplier: 5Holddown (hits): 0(0), Hello (hits): 1000(350)Rx Count: 352, Rx Interval (ms) min/max/avg: 1/1000/874 last: 464 ms agoTx Count: 351, Tx Interval (ms) min/max/avg: 756/1000/876 last: 524 ms agoElapsed time watermarks: 0 0 (last: 0)Registered protocols: CEF OSPFUptime: 00:05:07Last packet: Version: 1 - Diagnostic: 0State bit: Up - Demand bit: 0Poll bit: 0 - Final bit: 0Multiplier: 5 - Length: 24My Discr.: 8 - Your Discr.: 9Min tx interval: 1000000 - Min rx interval: 1000000Min Echo interval: 50000NeighAddr LD/RD RH/RS State Int10.1.0.2 6/6 Up Up Gi3/8.2Session state is UP and using echo function with 50 ms interval.OurAddr: 10.1.0.1Local Diag: 0, Demand mode: 0, Poll bit: 0MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 5Received MinRxInt: 1000000, Received Multiplier: 5Holddown (hits): 0(0), Hello (hits): 1000(352)Rx Count: 352, Rx Interval (ms) min/max/avg: 1/1000/880 last: 248 ms agoTx Count: 354, Tx Interval (ms) min/max/avg: 1/1000/875 last: 244 ms agoElapsed time watermarks: 0 0 (last: 0)Registered protocols: CEF OSPFUptime: 00:05:09Last packet: Version: 1 - Diagnostic: 0State bit: Up - Demand bit: 0Poll bit: 0 - Final bit: 0Multiplier: 5 - Length: 24My Discr.: 6 - Your Discr.: 6Min tx interval: 1000000 - Min rx interval: 1000000Min Echo interval: 50000MIB Walk for BFD MIB: Example
This example shows sample output from a MIB walk of the BFD MIB:
ciscoBfdSessMapTable
ciscoBfdSessMapBfdIndex.1.7.1.4.10.1.0.1 = 65543ciscoBfdSessMapBfdIndex.3.1.2.16.221.221.0.0.0.0.0.0.0.0.0.0.0.0.0.2 = 196609ciscoBfdSessMapBfdIndex.4.6.1.4.40.4.0.1 = 262150The MapTable index includes the following information about BFD sessions and clients:Index example: 1.7.1.4.10.1.0.11 - Client id7 - Local discriminator1 - IP address type (1 - IPv4, 2- IPv6)4 - Length of next string (4 for IPv4 addresses or 16 for IPv6 addresses)10.1.0.1 - IP address of the BFD sessionciscoBfdSessTable
ciscoBfdSessApplicationId.65543 = 1ciscoBfdSessApplicationId.196609 = 3ciscoBfdSessApplicationId.262150 = 4ciscoBfdSessDiscriminator.65543 = 7ciscoBfdSessDiscriminator.196609 = 1ciscoBfdSessDiscriminator.262150 = 6ciscoBfdSessRemoteDiscr.65543 = 7ciscoBfdSessRemoteDiscr.196609 = 1ciscoBfdSessRemoteDiscr.262150 = 6ciscoBfdSessUdpPort.65543 = 3785ciscoBfdSessUdpPort.196609 = 3784ciscoBfdSessUdpPort.262150 = 3785ciscoBfdSessState.65543 = upciscoBfdSessState.196609 = upciscoBfdSessState.262150 = upciscoBfdSessRemoteHeardFlag.65543 = falseciscoBfdSessRemoteHeardFlag.196609 = falseciscoBfdSessRemoteHeardFlag.262150 = falseciscoBfdSessOperMode.65543 = asyncModeWEchoFunciscoBfdSessOperMode.196609 = asynchModeWOEchoFunciscoBfdSessOperMode.262150 = asyncModeWEchoFunciscoBfdSessDemandModeDesiredFlag.65543 = falseciscoBfdSessDemandModeDesiredFlag.196609 = falseciscoBfdSessDemandModeDesiredFlag.262150 = falseciscoBfdSessEchoFuncModeDesiredFlag.65543 = trueciscoBfdSessEchoFuncModeDesiredFlag.196609 = falseciscoBfdSessEchoFuncModeDesiredFlag.262150 = trueciscoBfdSessControlPlanIndepFlag.65543 = falseciscoBfdSessControlPlanIndepFlag.196609 = falseciscoBfdSessControlPlanIndepFlag.262150 = falseciscoBfdSessAddrType.65543 = ipv4ciscoBfdSessAddrType.196609 = ipv6ciscoBfdSessAddrType.262150 = ipv4ciscoBfdSessAddr.65543 = 28:01:00:01ciscoBfdSessAddr.196609 = DD:DD:00:00:00:00:00:00:00:00:00:00:00:00:00:02ciscoBfdSessAddr.262150 = 10:04:00:01ciscoBfdSessDesiredMinTxInterval.65543 = 1000000ciscoBfdSessDesiredMinTxInterval.196609 = 50000ciscoBfdSessDesiredMinTxInterval.262150 = 1000000ciscoBfdSessReqMinRxInterval.65543 = 1000000ciscoBfdSessReqMinRxInterval.196609 = 50000ciscoBfdSessReqMinRxInterval.262150 = 1000000ciscoBfdSessReqMinEchoRxInterval.65543 = 50000ciscoBfdSessReqMinEchoRxInterval.196609 = 0ciscoBfdSessReqMinEchoRxInterval.262150 = 50000ciscoBfdSessDetectMult.65543 = 5ciscoBfdSessDetectMult.196609 = 5ciscoBfdSessDetectMult.262150 = 5ciscoBfdSessStorType.65543 = volatileciscoBfdSessStorType.196609 = volatileciscoBfdSessStorType.262150 = volatileciscoBfdSessRowStatus.65543 = activeciscoBfdSessRowStatus.196609 = activeciscoBfdSessRowStatus.262150 = activeciscoBfdSessAuthPresFlag.65543 = falseciscoBfdSessAuthPresFlag.196609 = falseciscoBfdSessAuthPresFlag.262150 = falseciscoBfdSessAuthenticationType.65543 = 0ciscoBfdSessAuthenticationType.196609 = 0ciscoBfdSessAuthenticationType.262150 = 0ciscoBfdSessPerfTable
ciscoBfdSessPerfPktIn.65543 = 246ciscoBfdSessPerfPktIn.196609 = 5159ciscoBfdSessPerfPktIn.262150 = 290ciscoBfdSessPerfPktOut.65543 = 247ciscoBfdSessPerfPktOut.196609 = 5416ciscoBfdSessPerfPktOut.262150 = 291ciscoBfdSessUpTime.65543 = 43376ciscoBfdSessUpTime.196609 = 39781ciscoBfdSessUpTime.262150 = 39736ciscoBfdSessPerfLastSessDownTime.65543 = 0ciscoBfdSessPerfLastSessDownTime.196609 = 0ciscoBfdSessPerfLastSessDownTime.262150 = 0ciscoBfdSessPerfLastCommLostDiag.65543 = 0ciscoBfdSessPerfLastCommLostDiag.196609 = 0ciscoBfdSessPerfLastCommLostDiag.262150 = 0ciscoBfdSessPerfSessUpCount.65543 = 1ciscoBfdSessPerfSessUpCount.196609 = 1ciscoBfdSessPerfSessUpCount.262150 = 1ciscoBfdSessPerfDiscTime.65543 = 0ciscoBfdSessPerfDiscTime.196609 = 0ciscoBfdSessPerfDiscTime.262150 = 0ciscoBfdSessPerfPktInHC.65543 = 247ciscoBfdSessPerfPktInHC.196609 = 5179ciscoBfdSessPerfPktInHC.262150 = 291ciscoBfdSessPerfPktOutHC.65543 = 248ciscoBfdSessPerfPktOutHC.196609 = 5440ciscoBfdSessPerfPktOutHC.262150 = 292Additional References
The following sections provide references related to the Bidirectional Forwarding Detection MIB.
Related Documents
Standards
MIBs
BFD MIB
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
RFCs
Technical Assistance
Feature Information for the Bidirectional Forwarding Detection MIB
Table 1 lists the release history for this MIB.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note
Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks. Third party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1005R)
Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.
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