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Cisco Express Forwarding—SNMP CEF-MIB Support

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Cisco Express Forwarding—SNMP CEF-MIB Support

Table Of Contents

Cisco Express Forwarding—SNMP CEF-MIB Support

Contents

Prerequisites for Cisco Express Forwarding—SNMP CEF-MIB Support

Restrictions for Cisco Express Forwarding—SNMP CEF-MIB Support

Information About Cisco Express Forwarding—SNMP CEF-MIB Support

Cisco Express Forwarding Functional Overview

CISCO-CEF-MIB Benefits

CEF Information Managed by the CISCO-CEF-MIB

CISCO-CEF-MIB Object Groups and Related Tables

Brief Description of the Tables in the CISCO-CEF-MIB

CEF Configuration and Monitoring Operations Available Through the CISCO-CEF-MIB

CISCO-CEF-MIB Notifications

How to Configure Cisco Express Forwarding—SNMP CEF-MIB Support

Configuring the Router to Use SNMP

Configuring an SNMP Host to Receive CISCO-CEF-MIB Notifications

What to Do Next

Configuring SNMP Notifications for Cisco Express Forwarding Events

Prerequisites

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notification

Configuration Examples for Cisco Express Forwarding—SNMP CEF-MIB Support

Configuring an SNMP Host to Receive CISCO-CEF-MIB Notifications: Example

Configuring SNMP Notifications for Cisco Express Forwarding Events: Example

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notifications: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

snmp mib cef throttling-interval

snmp-server enable traps cef

snmp-server host

Feature Information for Cisco Express Forwarding—SNMP CEF-MIB Support

Glossary


Cisco Express Forwarding—SNMP CEF-MIB Support


First Published: December 4, 2006
Last Updated: December 4, 2006

The Cisco Express Forwarding—SNMP CEF-MIB Support feature introduces the CISCO-CEF-MIB that allows management applications through the use of the Simple Network Management Protocol (SNMP) to configure and monitor Cisco Express Forwarding (CEF) operational data and to provide notification when CEF encounters specific configured events. This module describes how to use the CISCO-CEF-MIB to manage and monitor objects related to CEF operation.

CEF is an advanced Layer 3 IP switching technology. It optimizes network performance and scalability for all kinds of networks: those that carry small amounts of traffic and those that carry large amounts of traffic in complex patterns, such as the Internet and networks characterized by intensive web-based applications or interactive sessions.

Finding Feature Information in This Module

Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for Cisco Express Forwarding—SNMP CEF-MIB Support" section.

Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images

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

Prerequisites for Cisco Express Forwarding—SNMP CEF-MIB Support

Restrictions for Cisco Express Forwarding—SNMP CEF-MIB Support

Information About Cisco Express Forwarding—SNMP CEF-MIB Support

How to Configure Cisco Express Forwarding—SNMP CEF-MIB Support

Configuration Examples for Cisco Express Forwarding—SNMP CEF-MIB Support

Additional References

Command Reference

Feature Information for Cisco Express Forwarding—SNMP CEF-MIB Support

Glossary

Prerequisites for Cisco Express Forwarding—SNMP CEF-MIB Support

The Cisco Express Forwarding—SNMP CEF-MIB Support feature has the following prerequisites:

CEF or distributed CEF (dCEF) must be configured on your system.

The Cisco Express Forwarding infrastructure introduced in Cisco IOS Release12.2(22)S must be included in the image on your system.

The router on which the Cisco Express Forwarding—SNMP CEF-MIB Support features is to be used should be configured for SNMP access. Refer to the "Configuring the Router to Use SNMP" section in this document for more information.

Restrictions for Cisco Express Forwarding—SNMP CEF-MIB Support

The CISCO-CEF-MIB prefix database and its related database can be very large. Therefore, walking the prefix table could take a considerable amount of time.

Information About Cisco Express Forwarding—SNMP CEF-MIB Support

To configure SNMP and the CISCO-CEF-MIB to monitor CEF data and events, you should understand the following concepts:

Cisco Express Forwarding Functional Overview

CISCO-CEF-MIB Benefits

CEF Information Managed by the CISCO-CEF-MIB

CISCO-CEF-MIB Object Groups and Related Tables

Brief Description of the Tables in the CISCO-CEF-MIB

CEF Configuration and Monitoring Operations Available Through the CISCO-CEF-MIB

CISCO-CEF-MIB Notifications

Cisco Express Forwarding Functional Overview

CEF is an advanced Layer 3 IP switching technology. It uses a Forwarding Information Base (FIB) to make IP destination prefix-based switching decisions. The FIB is conceptually similar to a routing table or information base. It maintains the forwarding information contained in the IP routing table. When routing or topology changes occur in the network, the IP routing table is updated, and those changes are propagated to the FIB. The FIB maintains next-hop address information based on the information in the IP routing table. The two main components of CEF operation are the FIB and Adjacency tables.

CEF uses adjacency tables to prepend Layer 2 addressing information. The adjacency table maintains Layer 2 next-hop addresses for all FIB entries. Nodes in the network are said to be adjacent if they can reach each other with a single hop across a link layer. CEF discovers and solves adjacencies and populates the adjacency tables.

CISCO-CEF-MIB Benefits

Command-line interface (CLI) show commands are available to obtain CEF operational information. Managing CEF using the CLI can be a time consuming task. The increasing capacity of Cisco routers makes parsing through the show commands output to obtain the needed CEF operational parameters more and more difficult.

In Cisco IOS Release 12.2(31)SB and later releases, the CISCO-CEF-MIB allows you to manage and monitor the CEF operation using SNMP. In addition, you can configure SNMP to notify you if CEF encounters errors.

With the CISCO-CEF-MIB introduced with the Cisco Express Forwarding—SNMP CEF-MIB Support feature, you can access in real time operational information stored in the FIB and adjacency tables, switching statistics, information on resource failures, and configure parameters related to CEF features by utilizing a MIB implementation based on SNMP. This information is accessed using get and set commands entered on the network management system (NMS) workstation or host system for which SNMP has been implemented. The NMS workstation is also known as the SNMP manager.

CEF is available in all Cisco routers. However, CISCO-CEF-MIB support of CEF management is dependent on the new infrastructure introduced in Cisco IOS Release 12.2(22)S.

The implementation of the CISCO-CEF-MIB in Cisco IOS Release 12.2(31)SB2 manages CEF instances running on the Route Processor (RP). Information about CEF running on the line cards is available to the RP about CEF peers only.

The CISCO-CEF-MIB supports configuration and monitoring for both IP Versions, IP Version  4 (IPv4) and Version 6 (IPv6).

CEF Information Managed by the CISCO-CEF-MIB

SNMP has historically been used to collect network information. SNMP permits retrieval of critical information from network elements such as routers, switches, and workstations.

The CISCO-CEF-MIB provides managed objects that enable a network administrator to monitor the following:

CEF administrative and operational states as displayed in the output of the show ip cef summary command

Notifications for CEF events: CEF state changes, CEF failures (with a predefined reason), and Route Processor (RP) and line card inconsistencies.

CEF-related parameters for the associated interface as displayed by the show cef interface command)

Line card CEF states and line card CEF FIB states in the Linecard table as displayed by the show cef linecard command

CEF statistics: switching statistics, punt and punt-to-host counters as displayed by the show ip cef switching stats command, and per-prefix counters and nonrecursive counters

Notification for both IPv4 and IPv6, when CEF is switched between disable and enable and between CEF and distributed CEF

The SNMP CISCO-CEF-MIB provides managed objects that enable a network administrator to configure the following:

CEF and dCEF administration status:

CEF accounting-related parameters

CEF load sharing-related parameters

Traffic-related configuration parameters

CISCO-CEF-MIB Object Groups and Related Tables

The SNMP CISCO-CEF-MIB allows the configuration and management of CEF related objects. The MIB contains the following object groups:

CEF FIB group

CEF Adjacency group

CEF Forwarding Element group

CEF Cfg group

CEF Interface group

CEF Peer group

CEF Consistency (CC) group

CEF State Group

CEF Notification Control group

In the CISCO-CEF-MIB, configuration objects are defined as read-write and the other objects are defined as read-only.

The CISCO-CEF-MIB contains tables related to the CEF object groups. These tables provide information about prefixes, forwarding paths, adjacencies, output chain elements (OCEs), prefix-based statistics, information about CEF configuration, consistency checkers, switching statistics, and line card-specific managed objects.

The CISCO-CEF-MIB also defines CEF notifications that you can enable or disable through the MIB or CLI commands.

The index for most tables in the CISCO-CEF-MIB is entPhysicalIndex.

Brief Description of the Tables in the CISCO-CEF-MIB

Following is a list and a brief description of the tables provided by the CISCO-CEF-MIB:

The CEF FIB Summary table (cefFIBSummaryTable) contains the number of forwarding prefixes for both IPv4 and IPv6 protocols; a summary of the CEF Forwarding table.

The CEF Forwarding table (cefPrefixTable) lists all the prefixes and related counters. It also contains a pointer to the Forwarding Element Selection table.

The CEF Longest Match Prefix table (cefLMPrefixTable) returns the longest prefix match for the given destination address. An optional cefLMPrefixSpinLock object is provided to reduce conflict in instances when more than one application acts on the CEF Longest Match Prefix table.

The CEF Path table (cefPathTable) lists all the Cisco Express Forwarding paths.

The CEF Adjacency Summary table (cefAdJSummaryTable) contains the total number of complete, incomplete, fixup, and redirect adjacencies for all link types.

The CEF Adjacency table (cefAdjTable) lists all the adjacencies. It contains the adjacency source, encapsulation string, fixup, and Layer 3 maximum transmission unit (MTU) associated with the adjacency entry. It contains a pointer to the forwarding element selection table (if the adjacency is a MID chain adjacency).

The CEF Forwarding Element Selection table (cefFESelectionTable) represents the OCE chains in flattened format. This table shows only the labels, table ID, and adjacency traversed in the OCE chain. It also contains the weight associated with each OCE chain.

CEF Cfg table (cefCfgTable) contains all the global configuration parameters related to CEF: administration and operational status, accounting-related configuration parameters, load-sharing algorithms and IDs, and traffic statistics parameters.

CEF Interface table (cefIntTable) contains the interface specific CEF parameter: interface switching state, interface load sharing (per packet and per destination), and interface nonrecursive routing (internal and external).

CEF Peer table or Linecard table (cefPeerTable) contains CEF information related to peers on a managed line card: line card operational state and the number of time the line card session resets.

CEF Peer FIB table (cefPeerFIBTable) contains information about the operational state of the Forwarding Information Bases (FIBs) on each line card.

The CEF Prefix Length Statistics table (cefStatsPrefixTable) maintains prefix length-based statistics.

CEF Switching Stats table (cefSwitchingStatsTable) contains the switching statistics for each switching path: drop counters, punt counters, and punt-to-host counters.

CEF IP Prefix Consistency Checker Global group (cefCCGlobalTable) contains all global configuration parameter for the consistency checkers: auto repair, enable and disable, delay, and hold down; enable or disable the passive consistency checkers; enable or disable the error messages for consistency detection; and the mechanism to activate the full scan consistency checkers. This table also displays the state of full scan consistency checkers.

CEF Consistency Checker Type table (cefCCTypeTable) contains the consistency checker type specific parameters: frequency and count of scan for passive scanners and the queries sent, ignored, checked, and iterated.

CEF Inconsistency Record table (cefInconsistencyRecordTable) contains the detected inconsistency records: prefix address and length, table ID, consistency checker type, slot ID, and the reason for the inconsistency (missing or checksum error).

See "CEF Configuration and Monitoring Operations Available Through the CISCO-CEF-MIB" section for information about the specific objects available through the CISCO-CEF-MIB tables.

Figure 1 shows the contents of the CISCO-CEF-MIB core tables and the relationships of the tables to one another.

Figure 1 CISCO-CEF-MIB Main Tables, Table Contents, and Relationships

CEF Configuration and Monitoring Operations Available Through the CISCO-CEF-MIB

You can use SNMP get and set commands to configure and monitor CEF operations that are available through the CISCO-CEF-MIB tables. This section describes the configuration and monitoring operations for each table.

Table 1 lists the CEF monitoring operations and associated MIB objects provided by the CEF FIB Summary table (cefFIBSummaryTable).

Table 1 CEF FIB Summary Table—CEF Operation and Associated MIB Object

CEF Operation
Description

Gets the number of forwarding prefixes for IPv4 and IPv6

cefFIBSummaryFwdPrefixes

Table 2 lists the CEF monitoring operations and associated MIB objects provided by the CEF Forwarding table (cefPrefixTable).

Table 2 CEF Forwarding Table—CEF Operations and Associated MIB Objects 

CEF Operation
MIB Object

Gets the forwarding information for the entry

cefPrefixForwardingInfo

Gets the number of packets forwarded by the prefix

cefPrefixPkts

Gets the number of packets forwarded by the prefix in a 64-bit value

cefPrefixHCPkts

Gets the number of bytes forwarded by the prefix

cefPrefixBytes

Gets the number of bytes forwarded by the prefix in a 64-bit value

cefPrefixHCBytes

Gets the number of internal nonrecursive packets forwarded by the prefix

cefPrefixInternalNRPkts

Gets the number of internal nonrecursive packets forwarded by the prefix in a 64-bit value

cefPrefixInternalNRHCPkts

Gets the number of internal non-recursive bytes forwarded by the prefix

cefPrefixInternalNRBytes

Gets the number of internal non-recursive bytes forwarded by the prefix in a 64-bit value

cefPrefixInternalNRHCBytes

Gets the number of external non-recursive packets forwarded by the prefix

cefPrefixExternalNRPkts

Gets the number of external non-recursive packets forwarded by the prefix in a 64-bit value

cefPrefixExternalNRHCPkts

Gets the number of external non-recursive bytes forwarded by the prefix

cefPrefixExternalNRBytes

Gets the number of external non-recursive bytes forwarded by the prefix in 64-bit value

cefPrefixExternalNRHCBytes


Table 3 lists the CEF monitoring operations and associated MIB objects provided by the CEF Longest Match Prefix table (cefLMPrefixTable).

Table 3 CEF Longest Match Prefix Table—CEF Operations and Associated MIB Objects 

CEF Operation
MIB Object

Gets or sets the lock for creation or modification of the longest match prefix entries

cefLMPrefixSpinLock

Gets the state of the destination prefix request

cefLMPrefixState

Gets the network prefix address for the destination prefix request

cefLMPrefixAddr

Gets the network prefix length for the destination prefix request (the same display as the show ip cef exact-route command)

cefLMPrefixLen

Gets the status of a table entry

cefLMPrefixRowStatus


Table 4 lists the CEF monitoring operations and associated MIB objects provided by the CEF Path table (cefPathTable).

Table 4 CEF Path Table—CEF Operations and Associated MIB Objects

CEF Operation
MIB Object

Gets the type of CEF path for a prefix

cefPathType

Gets interface associated with this CEF path

cefPathInterface

Gets the next-hop address for the CEF path

cefPathNextHopAddr

Gets the recursive Virtual Private Network (VPN) routing and forwarding (VRF) instance name associated with this path

cefPathRecurseVrfName


Table 5 lists the CEF monitoring operations and associated MIB objects provided by the CEF Adjacency Summary table (cefAdjSummaryTable).

Table 5 CEF Adjacency Summary Table—CEF Operations and Associated MIB Objects

CEF Operation
MIB Objects

Gets the number of complete adjacencies

cefAdjSummaryComplete

Gets the number of incomplete adjacencies

cefAdjSummaryInComplete

Gets the number of adjacencies for Layer 2 Encapsulation

cefAdjSummaryFixup

Gets the number of adjacencies for IP redirect

cefAdjSummaryRedirect


Table 6 lists the CEF monitoring operations and associated MIB objects provided by the Adjacency table (cefAdjTable).

Table 6 CEF Adjacency Table—CEF Operations and Associated MIB Objects 

CEF Operation
MIB Object

Gets the adjacency source

cefAdjSource

Gets the adjacency Layer 2 encapsulation

cefAdjEncap

Gets the adjacency fix-up

cefAdjFixup

Gets the Layer 3 maximum transmission unit (MTU) for the adjacency

cefAdjMTU

Gets the forwarding information in cefFESelectionTable

cefAdjForwardingInfo

Gets the number of packets transmitted

cefAdjPkts

Gets the number of packets transmitted in a 64-bit version

cefAdjHCPkts

Gets the number of bytes transmitted

cefAdjBytes

Gets the number of bytes transmitted in a 64-bit version

cefAdjHCBytes


Table 7 lists the CEF monitoring operations and associated MIB objects provided by the CEF Forwarding Element Selection table (cefFESelectionTable).

Table 7 CEF Forwarding Element Selection Table—CEF Operations and Associated MIB Objects

CEF Operation
MIB Object

Gets any special processing for a forwarding element

cefFESelectionSpecial

Gets the Multiprotocol Label Switching (MPLS) labels for forwarding element

cefFESelectionLabels

Gets the adjancency type for the forwarding element

cefFESelectionAdjLinkType

Gets the interface for the adjacency for the forwarding element

cefFESelectionAdjInterface

Gets the next-hop address type for the adjacency for the forwarding element

cefFESelectionAdjNextHopAddrType

Gets the next-hop address for the adjacency for the forwarding element

cefFESelectionAdjNextHopAddr

Gets the connection ID for the adjacency for the forwarding element

cefFESelectionAdjConnId

Gets the VRF name for the lookup for the forwarding element

cefFESelectionVrfName

Gets the weighting for load balancing for the forwarding element

cefFESelectionWeight


Table 8 lists the CEF configuration and monitoring operations and associated MIB objects provided by the CEF Cfg table (cefCfgTable).

Table 8 CEF Cfg Table—CEF Operations and Associate MIB Objects 

CEF Operation
MIB Objects

Enables or disables a CEF instance

cefCfgAdminState

Queries a CEF operational instance

cefCfgOperState

Enables or disables a dCEF instance

cefCfgDistributionAdminState

Queries a dCEF operational instance

cefCfgDistributionOperState

Gets or sets CEF network accounting options

cefCfgAccountingMap

nonRecursive (0)

perPrefix (1)

prefixLength (2)

Gets or sets CEF load sharing algorithm options

cefCfgLoadSharingAlgorithm

none (1) - Load sharing is disabled.

original (2)

tunnel (3)

universal (4)

Gets or sets a load sharing ID

cefCfgLoadSharingID

Gets or sets a traffic interval timer for CEF traffic statistics

cefCfgTrafficStatsLoadInterval

Gets or sets a frequency timer for the line card to send traffic statistics to the RP

cefCfgTrafficStatsUpdateRate


Table 9 lists the CEF monitoring operations and associated MIB objects provided by the CEF Resource table (cefResourceTable).

Table 9 CEF Resource Table—CEF Operations and Associate MIB Objects

CEF Operation
MIB Object

Gets the memory status of process memory pool for CEF

cefResourceMemoryUsed

Gets the reason for the CEF resource failure notification

cefResourceFailureReason


Table 10 lists the CEF configuration and monitoring operations and associated MIB objects provided by the CEF Interface table (cefIntTable).

Table 10 CEF Interface Table—CEF Operations and Associate MIB Objects

CEF Operation
MIB Objects

Gets or sets the CEF switching state of the interface

cefIntSwitchingState

cefEnabled (1)

distCefEnabled (2)

cefDisabled (3)

Gets or sets the kind of CEF Load sharing on the interface

cefIntLoadSharing

perPacket (1)

perDestination (2)

Gets or sets CEF non-recursive accounting on the interface

cefIntNonrecursiveAccouting

internal (1)

external (2)


Table 11 lists the CEF monitoring operations and associated MIB objects provided by the CEF Peer table (or Linecard table) (cefPeerTable).

Table 11 CEF Peer Table—CEF Operations and Associate MIB Objects

CEF Operation
MIB Objects

Gets the CEF operational instance of the peer entity

cefPeerOperState

Gets the number of times the session with the Peer resets

cefPeerNumberOfResets


Table 12 lists the CEF monitoring operation and associated MIB object provided by the CEF Peer FIB table (cefPeerFIBTable).

Table 12 CEF Peer FIB Table—CEF Operation and Associate MIB Object

CEF Operation
MIB Objects

Gets the current CEF FIB operation state of the peer entity

cefPeerFIBOperState


Table 13 lists the CEF monitoring operations and associated MIB objects provided by the CEF Prefix length Statistics table (cefStatsPrefixTable).

Table 13 CEF Prefix Length Statistics Table—CEF Operations and Associated MIB Objects 

CEF Operation
MIB Object

Gets the number of queries (lookups) in the FIB database for a prefix length

cefStatsPrefixQueries

Gets the number of queries (lookups) in the FIB database for a prefix length in a 64-bit value

cefStatsPrefixHCQueries

Gets the number of inserts in the FIB database for a prefix length

cefStatsPrefixInserts

Gets the number of inserts in the FIB database for a prefix length in a 64-bit value

cefStatsPrefixHCInsert

Gets the number of deletes in the FIB database for a prefix length

cefStatsPrefixDeletes

Gets the number of deletes in the FIB database for a prefix length in a 64-bit version

cefStatsPrefixHCDeletes

Gets the number of elements in the FIB database for a prefix length

cefStatsPrefixElements

Gets the number of elements in the FIB database for a prefix length in a 64-bit value

cefStatsPrefixHCElements


Table 14 lists the CEF monitoring operations and associated MIB objects provided by the CEF Switching Statistics table (cefSwitchingStatsTable).

Table 14 CEF Switching Statistics Table—CEF Operations and Associate MIB Objects 

CEF Operation
MIB Objects

Gets the switching path of a CEF instance

cefSwitchingPath

Gets the number of packets dropped by a CEF instance

cefSwitchingDrop

Gets the number of packets dropped by a CEF instance in a 64-bit value

cefSwitchingHCDrop

Gets the number of packets that could be punted

cefSwitchingPunt

Gets the number of packets that could be punted in a 64-bit value

cefSwitchingHCPunt

Gets the number of packets that are punted to the host

cefSwitchingPunt2Host

Gets the number of packets that are punted to the host in a 64-bit value

cefSwitchingHCPunt2Host


Table 15 lists the CEF configuration and monitoring operations and associated MIB objects provided by the CEF IP Prefix Consistency Checker group (cefCCGlobalTable).

Table 15 CEF IP Prefix Consistency Checker Group—CEF Operations and Associate MIB Objects

CEF Operation
MIB Objects

Enables or disables auto repairing of the consistency checkers

cefCCGlobalAutoRepairEnabled

Gets or sets the consistency checker wait time before fixing the inconsistency

cefCCGlobalAutoRepairDelay

Gets or sets the consistency checker wait time to re-enable auto-repair after auto-repair runs

cefCCGlobalAutoRepairHoldDown

Enables or disables error message generation for an inconsistency

cefCCGlobalErrorMsgEnabled


Table 16 lists the CEF configuration and monitoring operations and associated MIB objects provided by the CEF Consistency Checker Type table (cefCCTypeTable).

Table 16 CEF Consistency Checker Type Table—CEF Operations and Associate MIB Objects 

CEF Operation
MIB Objects

Enables or disables the passive consistency checker

cefCCEnabled

Get or sets the maximum number of prefixes per scan

cefCCCount

Gets or sets the period between scans for the consistency checker

cefCCPeriod

Gets the number of prefix consistency queries sent to the CEF FIB

cefCCQueriesSent

Gets the number of prefix consistency queries ignored by the consistent checker

cefCCQueriesIgnored

Gets the number of prefix consistent queries iterated back to the database

cefCCQueriesIterated

Gets the number of prefix consistent queries processed

cefCCQueriesChecked


Table 17 lists the CEF configuration and monitoring operations and associated MIB objects provided by the CEF Inconsistency Record table (cefInconsistencyRecordTable).

Table 17 CEF Inconsistency Record Table—CEF Operations and Associate MIB Objects

CEF Operation
MIB Objects

Gets the network prefix type for the inconsistency

cefInconsistencyPrefixType

Gets the network prefix address for the inconsistency

cefInconsistencyPrefixAddr

Gets the network prefix length for the inconsistency

cefInconsistencyPrefixLen

Gets the VRF name for the inconsistency

cefInconsistencyVrfName

Gets the consistency checker type that found the inconsistency

cefInconsistencyCCType

Gets the entity in which this inconsistency occurred

cefInconsistencyEntity

Gets the reason for generating the inconsistency

cefInconsistencyReason

missing (1)

checksumErr (2)

unknown (3)

Global Objects for CEF Inconsistency

Gets the value of the system uptime at the time an inconsistency was detected

entLastInconsistencyDetectTime

Sets an object to restart all active consistency checkers

cefInconsistencyReset

Gets the status of the inconsistency reset request

cefInconsistencyResetStatus


CISCO-CEF-MIB Notifications

Table 18 lists the CEF operations associated with the CISCO-CEF-MIB objects that enable the sending of CEF notifications.

Table 18 CEF Notifications—CEF Operations and CISCO-CEF-MIB Objects that Enable Them

CEF Operation
MIB Object

Enables the sending of a notification on the detection of a CEF resource failure.

cefResourceFailureNotifEnable

Enables the sending of a notification on the detection of a CEF peer state change.

cefPeerStateChangeNotifEnable

Enables the sending of a notification on the detection of a CEF FIB peer state change.

cefPeerFIBStateChangeNotifEnable

Sets the period of time between the sending of notification events.

cefNotifThrottlingInterval

Enables the sending of a notification on the detection of an inconsistency.

cefInconcsistencyNotifEnable


You can enable or disable these notifications through the MIB or by entering a CLI command. Table 19 contains a description of the notifications and the commands you use to enable each notification.


Note You must enter a snmp-server host command before you enter a command to enable or disable a CISCO-CEF-MIB notification.


Table 19 Description of Notifications and Enabling Commands for the CEF-PROVISION-MIB Notifications 

Notification
Generated for
Commands

CEF resource failure notification

A malloc failure, an Inter-Process Communication (IPC) failure, and any other type of failure related to External Data Representation (XDR) Messages

CLI: snmp-server enable traps cef resource-failure

MIB: setany version ip-address community-string cefResourceFailureNotifEnable.0 -i 1

CEF peer state change notification

A change in the operational state of a peer on the line cards

CLI: snmp-server enable traps cef peer-state-change

MIB: setany version ip-address community-string cefPeerStateChangeNotifEnable.0 -i 1

CEF peer FIB state change notification

A change in the operational state of the peer FIB

CLI: snmp-server enable traps cef peer-fib-state-change

MIB: setany version ip-address community-string cefPeerFIBStateChangeNotifEnable.0 -i 1

CEF inconsistency detection notification

An inconsistencies detected by the consistency checkers

CLI: snmp-server enable traps cef inconsistency

MIB: setany version ip-address community-string cefInconsistencyNotifEnable.0 -i 1


How to Configure Cisco Express Forwarding—SNMP CEF-MIB Support

Perform the following tasks to configure Cisco Express Forwarding—SNMP CEF-MIB Support.

Configuring the Router to Use SNMP (required)

Configuring an SNMP Host to Receive CISCO-CEF-MIB Notifications (required)

Configuring SNMP Notifications for Cisco Express Forwarding Events (required)

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notification (optional)

Configuring the Router to Use SNMP

Perform the following task to configure the router to use SNMP.

Before you can use the Cisco Express Forwarding—SNMP CEF-MIB Support feature, you must configure the SNMP server for the router.

SUMMARY STEPS

1. enable

2. configure terminal

3. snmp-server community string [view view-name] [ro | rw] [ipv6 nacl] [access-list-number]

4. snmp-server community string2 rw

5. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

snmp-server community string [view view-name] [ro | rw] [ipv6 nacl] [access-list-number]

Example:

Router(config)# snmp-server community public ro

Sets up the community access string to permit access to SNMP.

The string argument is a community string that consists of from 1 to 32 alphanumeric characters and functions much like a password, permitting access to the SNMP protocol. Blank spaces are not permitted in the community string.

The view view-name keyword-argument pair is the name of a previously defined view. The view defines the objects available to the SNMP community.

The ro keyword specifies read-only access. Authorized management stations can only retrieve MIB objects.

The rw keyword specifies read-write access. Authorized management stations can retrieve and modify MIB objects.

The ipv6 nacl keywords specify the IPv6 named access list.

The access-list-number argument is an integer from 1 to 99. It specifies a standard access list of IP addresses or a string (not to exceed 64 characters) that is the name of a standard access list of IP addresses allowed access to the SNMP agent.

Alternatively, an integer from 1300 to 1999 that specifies a list of IP addresses in the expanded range of standard access list numbers. Devices at these addresses are allowed to use the community string to gain access to the SNMP agent.

Note The string argument (Step 3) and string2 argument (Step 4) provide a minimal level of security. It is advisable to provide the string for read-only access to others who wish only to view and not to modify the MIB objects, and retain the read-write access string for administrators only. The string2 argument (Step 4) should be different from the read-only string argument specified in this step.

Step 4 

snmp-server community string2 rw

Example:

Router(config)# snmp-server community private rw

Sets up the community access string to permit access to SNMP.

The string2 argument is a community string that consists of from 1 to 32 alphanumeric characters and functions much like a password, permitting access to the SNMP protocol. Blank spaces are not permitted in the community string.

The rw keyword specifies read-write access. Authorized management stations can retrieve and modify MIB objects.

This example allows MIB objects to be retrieved and set because a string is specified with read-write access.

Note The string argument (Step 3) and string2 argument (Step 4) provide a minimal level of security. It is advisable to provide the string for read-only access to others who wish to only view and not to modify the MIB objects, and retain the read-write access string for administrators only. The string2 argument (Step 4) should be different from the read-only string argument specified in the preceding step (Step 3).

Step 5 

end

Example:

Router(config)# end

Exits to privileged EXEC mode.

Configuring an SNMP Host to Receive CISCO-CEF-MIB Notifications

Perform the following task to configure an SNMP host to receive CISCO-CEF-MIBnotifications. Notifications provide information to assist you in the monitoring and managing of CEF operations.

SUMMARY STEPS

1. enable

2. configure terminal

3. snmp-server community string [ro | rw]

4. snmp-server community string2 rw

5. snmp-server host ip-address [vrf vrf-name] [traps | informs] [version {1 | 2c | 3
[auth | noauth | priv]}] community-string [udp-port port] cef

6. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

snmp-server community string [ro | rw]

Example:

Router(config)# snmp-server community public ro

Sets up the community access string to permit access to SNMP.

The string argument is a community string that consists of from 1 to 32 alphanumeric characters and functions much like a password, permitting access to the SNMP protocol. Blank spaces are not permitted in the community string.

The ro keyword specifies read-only access. Authorized management stations can only retrieve MIB objects.

The rw keyword specifies read-write access. Authorized management stations can retrieve and modify MIB objects.

Step 4 

snmp-server community string2 rw

Example:

Router(config)# snmp-server community private rw

Sets up the community access string to permit access to SNMP.

The string2 argument is a community string that consists of from 1 to 32 alphanumeric characters and functions much like a password, permitting access to the SNMP protocol. Blank spaces are not permitted in the community string.

The rw keyword specifies read-write access. Authorized management stations can retrieve and modify MIB objects.

This example allows MIB objects to be retrieved and set because a string is specified with read-write access.

Note The string argument (Step 3) and string2 argument (Step 4) provide a minimal level of security. It is advisable to provide the string for read-only access to others who wish to only view and not to modify the MIB objects, and retain the read-write access string for administrators only. The string2 argument (Step 4) should be different from the read-only string argument specified in the preceding step (Step 3).

Step 5 

snmp-server host ip-address [vrf vrf-name] [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] cef

Example:

Router(config)# snmp-server host 10.56.125.47 informs version 2c public cef

Specifies the recipient of an SNMP notification operation.

The ip-address argument is the IP address or IPv6 address of the SNMP notification host.

The SNMP notification host is typically a network management station (NMS or SNMP manager). This host is the recipient of the SNMP traps or informs.

The vrf vrf-name keyword and argument specify that the specified VRF be used to send SNMP notifications.

The traps keyword specifies that notifications should be sent as traps. This is the default.

The informs keyword specifies that notifications should be sent as informs.

The version keyword specifies the version of the SNMP used to send the traps. The default is 1.

If you use the version keyword, one of the following keywords must be specified:

1—SNMPv1. This option is not available with informs.

2c—SNMPv2c.

3—SNMPv3. The most secure model because it allows packet encryption with the priv keyword. The default is noauth.

One of the following three optional security level keywords can follow the version 3 keywords:

auth—Enables Message Digest 5 (MD5) and Secure Hash Algorithm (SHA) packet authentication.

noauth—Specifies that the noAuthNoPriv security level applies to this host. This is the default security level for SNMPv3.

priv—Enables Data Encryption Standard (DES) packet encryption (also called "privacy").

The community-string argument specifies that a password-like community string be sent with the notification operation.

The udp-port port keyword and argument specify that SNMP notifications or informs are to be sent to the UDP port number of the NMS host. The default is 162.

The cef keyword specifies that the Cisco Express Forwarding notification type is to be sent to the host. If no type is specified, all available notifications are sent.

Step 6 

end

Example:

Router(config)# end

Exits to privileged EXEC mode.

What to Do Next

After you configure an SNMP host to receive the CISCO-CEF-MIB notifications, you can configure the notifications that you want to receive. See the "Configuring SNMP Notifications for Cisco Express Forwarding Events" section.

Configuring SNMP Notifications for Cisco Express Forwarding Events

Perform the following task to configure SNMP notifications for CEF events. You can complete the task through the use of CLI commands or SNMP commands.

Prerequisites

You need to configure an NMS or SNMP agent to receive the SNMPCISCO-CEF-MIB notification, see the "Configuring an SNMP Host to Receive CISCO-CEF-MIB Notifications" section

SUMMARY STEPS

Router CLI Commands

1. enable

2. configure terminal

3. snmp-server enable traps cef [peer-state-change] [resource-failure] [inconsistency] [peer-fib-state-change]

4. snmp-server host ip-address [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string cef

5. end

SNMP Commands

1. setany version ip-address community-string cefPeerStateChangeNotifEnable.0 -i TruthValue

2. setany version ip-address community-string cefPeerFIBStateChangeNotifEnable.0 -i TruthValue

3. setany version ip-address community-string cefResourceFailureNotifEnable.0 -i TruthValue

4. setany version ip-address community-string cefInconsistencyNotifEnable.0 -i TruthValue

DETAILED STEPS: Router CLI Commands

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

snmp-server enable traps cef [peer-state-change] [resource-failure] [inconsistency] [peer-fib-state-change]

Example:

Router(config)# snmp-server enable traps cef resource-failure

Enables Cisco Express Forwarding support of SNMP notifications on an NMS.

The peer-state change keyword enables the sending of CISCO-CEF-MIB SNMP notifications for changes in the operational state of CEF peers.

The resource-failure keyword enables the sending of CISCO-CEF-MIB SNMP notifications for resource failures that affect CEF operations.

The inconsistency keyword enables the sending of CISCO-CEF-MIB SNMP notifications for inconsistencies that occur when routing information is updated from the Routing Information Base (RIB) to the CISCO-CEF-MIB on the RP and to the CISCO-CEF-MIB on the line cards.

You can set the throttling interval for sending inconsistency notifications, see the "Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notification" section.

The peer-fib-state-change keyword enables the sending of CISCO-CEF-MIB SNMP notifications for changes in the operational state of the CEF peer FIB.

Step 4 

snmp-server host ip-address [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string cef

Example:

Router(config)# snmp-server host 10.56.125.47 informs version 2c public cef

Specifies the recipient of an SNMP notification operation.

The ip-address argument is the IP address or IPv6 address of the SNMP notification host.

The SNMP notification host is typically a network management station (NMS or SNMP manager). This host is the recipient of the SNMP traps or informs.

The traps keyword specifies that notifications should be sent as traps. This is the default.

The informs keyword specifies that notifications should be sent as informs.

The version keyword specifies the version of the SNMP used to send the traps. The default is 1.

If you use the version keyword, one of the following keywords must be specified:

1—SNMPv1. This option is not available with informs.

2c—SNMPv2C.

3—SNMPv3. The most secure model because it allows packet encryption with the priv keyword. The default is noauth.

One of the following three optional security level keywords can follow the version 3 keywords:

auth—Enables Message Digest 5 (MD5) and Secure Hash Algorithm (SHA) packet authentication.

noauth—Specifies that the noAuthNoPriv security level applies to this host. This is the default security level for SNMPv3.

priv—Enables Data Encryption Standard (DES) packet encryption (also called "privacy").

The community-string argument specifies that a password-like community string be sent with the notification operation.

The cef keyword specifies that the Cisco Express Forwarding notification type is to be sent to the host. If no type is specified, all available notifications are sent.

Step 5 

end

Example:

Router(config)# end

Exits to privileged EXEC mode.

DETAILED STEPS: SNMP Commands

 
Command or Action
Purpose

Step 1 

setany version ip-address community-string cefPeerStateChangeNotifEnable.0 -i TruthValue

Example:

workstation% setany -v2c 10.56.125.47 public cefPeeStateStateChangeNotifEnable.0 -1 1

Enables the sending of CISCO-CEF-MIB SNMP notifications for changes in operational state of Cisco Express Forwarding peers.

The version argument specifies the version of SNMP that is used. Options are

-v1—SNMPv1

-v2c—SNMPv2C

-v3—SNMPv3

The ip-address argument is the IP address or IPv6 address of the SNMP notification host.

The SNMP notification host is typically a network management station (NMS or SNMP manager). This host is the recipient of the SNMP traps or informs.

The community-string argument specifies that a password-like community string be sent with the notification operation.

The -i keywords indicate that the variable that follows is an integer.

Values for the TruthValue argument are:

1—enable sending of the notification

2—disable sending of the notification

These arguments and keywords apply to the Cisco-CEF-MIB notifications in steps 2, 3, and 4.

Step 2 

setany version ip-address community-string cefPeerFIBStateChangeNotifEnable.0 -i TruthValue

Example:

workstation% setany -v2c 10.56.125.47 public cefPeerFIBStateChangeNotifEnable.0 -1 1

Enables the sending of CISCO-CEF-MIB SNMP notifications for changes in the operational state of the CEF peer FIB.

See Step 1 for a description of the command arguments and keywords.

Step 3 

setany version ip-address community-string cefResourceFailureNotifEnable.0 -i TruthValue

Example:

workstation% setany -v2c 10.56.125.47 public cefResourceFailureNotifEnable.0 -i 1

Enables the sending of CISCO-CEF-MIB SNMP notifications for resource failures that affect Cisco Express Forwarding operations.

See Step 1 for a description of the command arguments and keywords.

Step 4 

setany version ip-address community-string cefInconsistencyNotifEnable.0 -i TruthValue

Example:

workstation% setany -v2c 10.56.125.47 public cefInconsistencyNotifEnable.0 -i 1

Enables the sending of CISCO-CEF-MIB SNMP notifications for inconsistencies that occur when routing information is updated from the RIB to the CEF FIB on the RP and to the CEF FIB on the line cards.

See Step 1 for a description of the command arguments and keywords.

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notification

Perform the following task to configure the throttling interval for CISCO-CEF-MIB inconsistency notifications.

Configuring a throttling interval allows some time before an inconsistency notification is sent during the process of updating forwarding information from the Routing Information Base (RIB) to the RP and to the line card databases. As these databases are updated, inconsistencies might result, due to the asynchronous nature of the distribution mechanism for these databases. The throttling interval allows fleeting inconsistencies to resolve themselves before sending an inconsistence notification.

SUMMARY STEPS

Router CLI Commands

1. enable

2. configure terminal

3. snmp-server enable traps cef inconsistency

4. snmp mib cef throttling-interval seconds

5. end

SNMP Commands

1. setany version ip-address community-string cefNotifThrottlingInterval.0 -i seconds

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

snmp-server enable traps cef inconsistency

Example:

Router(config)# snmp-server enable traps cef inconsistency

Enables the sending of CISCO-CEF-MIB SNMP notifications for inconsistencies in Cisco Express Forwarding.

Step 4 

snmp mib cef throttling-interval seconds

Example:

Router(config)# snmp mib cef throttling-interval 2500

Sets the throttling interval for the CISCO-CEF-MIB inconsistency notifications.

The seconds argument is the time to allow before an inconsistency notification is sent during the process of updating forwarding information from the RIB to the RP and to the line card databases. The valid value is from 1 to 3600 seconds. A value of 0 disables throttle control.

Step 5 

end

Example:

Router(config)# end

Exits to privileged EXEC mode.

:

DETAILED STEPS: SNMP Commands

 
Command or Action
Purpose

Step 1 

setany version ip-address community-string cefNotifThrottlingInterval.0 -i seconds

Example:

workstation% setany -v2c 10.56.125.47 public cefNotifThrottlingInterval.0 -1 3600

Sets the throttling interval for the CISCO-CEF-MIB inconsistency notifications.

The version argument specifies the version of SNMP that is used. Options are

-v1—SNMPv1

-v2c—SNMPv2C

-v3—SNMPv3

The ip-address argument is the IP address or IPv6 address of the SNMP notification host.

The SNMP notification host is typically a network management station (NMS or SNMP manager). This host is the recipient of the SNMP traps or informs.

The community-string argument specifies that a password-like community string be sent with the notification operation.

The -i keywords indicate that the variable that follows is an integer.

The seconds argument is the time to allow before an inconsistency notification is sent during the process of updating forwarding information from the RIB to the RP and to the line card databases. The valid value is from 1 to 3600 seconds. A value of 0 disables throttle control.

Configuration Examples for Cisco Express Forwarding—SNMP CEF-MIB Support

This section contains the following configuration examples for the Cisco Express Forwarding—SNMP CEF-MIB Support feature:

Configuring an SNMP Host to Receive CISCO-CEF-MIB Notifications: Example

Configuring SNMP Notifications for Cisco Express Forwarding Events: Example

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notifications: Example

Configuring an SNMP Host to Receive CISCO-CEF-MIB Notifications: Example

The following example shows how to configure an SNMP host to receive CISCO-CEF-MIB notifications:

configure terminal
!

snmp-server community public ro

snmp-server community private rw

snmp-server host 10.56.125.47 informs version 2vc public cef

end

This example sets up SNMP host 10.56.125.47 to receive CISCO-CEF-MIB notifications as informs.

Configuring SNMP Notifications for Cisco Express Forwarding Events: Example

This section contains examples for configuring SNMP notifications for CEF events using the CLI and using SNMP commands.

Configuring SNMP Notifications for Cisco Express Forwarding Events Using the CLI: Example

This example shows how to use the CLI to configure CISCO-CEF-MIB SNMP notifications to be sent to host 10.56.125.47 as informs for changes in CEF peer states and peer FIB states, for CEF resource failures, and for inconsistencies in CEF events:

configure terminal
!

snmp-server community public ro

snmp-server host 10.56.125.47 informs version 2c public cef

!
snmp-server enable traps cef peer-state-change
snmp-server enable traps cef peer-fib-state-change
snmp-server enable traps cef inconsistency
snmp-server enable traps cef resource-failure
end

Configuring SNMP Notifications for Cisco Express Forwarding Events Using SNMP Commands: Example

This example shows the use of SNMP command to configure CISCO-CEF-MIB SNMP notifications to be sent to host 10.56.125.47 for changes in CEF peer states and peer FIB states, for CEF resource failures, and for inconsistencies in CEF events:

setany -v2c 10.56.125.47 public cefPeerStateChangeNotifEnable.0 -i 1

setany -v2c 10.56.125.47 public cefPeerFIBStateChangeNotifEnable.0 -i 1

setany -v2c 10.56.125.47 public cefResourceFailureNotifEnable.0 -i 1
setany -v2c 10.56.125.47 public cefInconsistencyNotifEnabled.0 -i 1

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notifications: Example

This example shows the configuration of a throttling interval for the sending of CEF inconsistency notifications to the SNMP host using CLI commands and SNMP commands. The throttling interval is the amount of time that passes between the time that the inconsistency occurs and the sending of the notification to the SNMP host.

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notifications Using CLI Commands: Example

This example shows the addition of a throttling interval of 1000 seconds for the sending of CEF inconsistency notifications to the SNMP host using CLI commands:

configure terminal
!

snmp-server community public ro

snmp-server host 10.56.125.47 informs version 2c public cef

!
snmp-server enable traps cef peer-state-change
snmp-server enable traps cef peer-fib-state-change
snmp-server enable traps cef inconsistency
snmp-server enable traps cef resource-failure
!
snmp mib cef throttling-interval 1000
end

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notifications Using SNMP Commands: Example

This example shows the addition of a throttling interval of 1000 seconds for the sending of CEF inconsistency notifications to the SNMP host using an SNMP command:

setany -v2c 10.56.125.47 public cefNotifThrottlingInterval.0 -1 1000

Additional References

The following sections provide references related to the Cisco Express Forwarding—SNMP CEF-MIB Support feature.

Related Documents

Related Topic
Document Title

Commands for configuring and managing Cisco Express Forwarding

Cisco IOS IP Switching Services Command Reference

Overview of Cisco Express Forwarding

"Cisco Express Forwarding Overview"

Tasks for configuring Cisco Express Forwarding

"Configuring Basic Cisco Express Forwarding for Improved Performance, Scalability, and Resiliency in Dynamic Networks"


Standards

Standard
Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.


MIBs

MIB
MIBs Link

No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature.

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs


RFCs

RFC
Title

RFC 3291

Textual Conventions for Internet Network Addresses

RFC 3413

Simple Network Management Protocol (SNMP) Applications


Technical Assistance

Description
Link

The Cisco Technical Support & Documentation website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, tools, and technical documentation. Registered Cisco.com users can log in from this page to access even more content.

http://www.cisco.com/techsupport


Command Reference

This section documents new and modified commands only.

snmp mib cef throttling-interval

snmp-server enable traps cef

snmp-server host

snmp mib cef throttling-interval

To set the throttling interval for the CEF-MIB inconsistency notifications, use the snmp mib cef throttling-interval command in global configuration mode. To remove the throttling interval, use the no form of this command.

snmp mib cef throttling-interval seconds

no snmp mib cef throttling-interval seconds

Syntax Description

seconds

The time to allow before an inconsistency notification is sent during the process of updating forwarding information from the Routing Information Base (RIB) to the Route Processor (RP) and the line card databases. The valid value is from 0 to 3600 seconds.


Command Default

Throttling is disabled by default (throttling interval is set to 0 seconds).

Command Modes

Global configuration

Command History

Release
Modification

12.2(31)SB

This command was introduced.


Usage Guidelines

Use this command in conjunction with the snmp-server enable traps cef inconsistency command to set the time elapsed between the occurrence of a Cisco Express Forwarding database inconsistencies and the time when you want to receive an inconsistency notification.

If you set the throttling interval to 0 seconds, throttling is disabled.

Examples

The following example shows how to set the throttling interval for CEF-MIB inconsistency notification to 300 seconds:

configure terminal 
!
snmp-server enable traps cef inconsistency
snmp mib cef throttling-interval 300

Related Commands

Command
Description

snmp-server enable traps cef

Enables CEF-MIB notifications that correspond to Cisco Express Forwarding events.

snmp-server host

Specifies the recipient of an SNMP notification operation.


snmp-server enable traps cef

To enable Cisco Express Forwarding (CEF) support of Simple Network Management Protocol (SNMP) notifications on a network management system (NMS), use the snmp-server enable traps cef command in global configuration mode. To disable Cisco Express Forwarding support of SNMP notifications, use the no form of this command.

snmp-server enable traps cef [peer-state-change] [resource-failure] [inconsistency] [peer-fib-state-change]

no snmp-server enable traps cef [peer-state-change] [resource-failure] [inconsistency] [peer-fib-state-change]

Syntax Description

peer-state-change

Enables the sending of CEF-MIB SNMP notifications for changes in the operational state of CEF peers.

resource-failure

Enables the sending of CEF-MIB SNMP notifications for resource failures that affect Cisco CEF operations.

inconsistency

Enables the sending of CEF-MIB SNMP notifications for inconsistencies that occur when routing information is updated from the Routing Information Base (RIB) to the CEF Forwarding Information Base (FIB) on the Route Processor (RP) and to the CEF FIB on the line cards.

peer-fib-state-change

Enables the sending of CEF-MIB SNMP notifications for changes in the operational state of the CEF peer FIB.


Command Default

All CEF-MIB notifications are disabled by default.

Command Modes

Global configuration

Command History

Release
Modification

12.2(31)SB2

This command was introduced.


Usage Guidelines

You can use this command to enable CEF-MIB SNMP notifications that correspond to specific Cisco Express Forwarding events. To send the notifications to an NMS or host system, you need to configure the snmp-server host command with the cef keyword.

You can enable all CEF-MIB SNMP notifications if you enter the snmp-server enable traps cef command without entering an optional keyword.

Examples

The following example shows how to enable the router to send CEF peer state changes and forwarding inconsistencies as informs to the NMS with IP address 10.56.125.47 and to use the community string defined as public:

configure terminal
!
snmp-server enable traps cef peer-state-change inconsistency
snmp-server host 10.56.125.47 informs version 2c public

Related Commands

Command
Description

snmp-server community

Configures a community access string to permit SNMP access to the local router by the remote SNMP software client.

snmp-server host

Specifies the recipient of an SNMP notification operation.


snmp-server host

To specify the recipient of a Simple Network Management Protocol (SNMP) notification operation, use the snmp-server host command in global configuration mode. To remove the specified host from the configuration, use the no form of this command.

snmp-server host {hostname | ip-address} [vrf vrf-name] [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] [notification-type]

no snmp-server host {hostname | ip-address} [vrf vrf-name] [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] [notification-type]

Syntax Description

hostname | ip-address

Name, IP address, or IPv6 address of the SNMP notification host. The ip-address can be an IP or IPv6 address.

The SNMP notification host is typically a network management station (NMS or SNMP manager). This host is the recipient of the SNMP traps or informs.

vrf

(Optional) Specifies that a Virtual Private Network (VPN) routing and forwarding (VRF) instance should be used to send SNMP notifications.

vrf-name

(Optional) VPN VRF instance used to send SNMP notifications.

traps

(Optional) Specifies that notifications should be sent as traps. This is the default.

informs

(Optional) Specifies that notifications should be sent as informs.

version

(Optional) Version of the SNMP used to send the traps. The default is 1.

If you use the version keyword, one of the following keywords must be specified:

1—SNMPv1. This option is not available with informs.

2c—SNMPv2C.

3—SNMPv3. The most secure model because it allows packet encryption with the priv keyword. The default is noauth.

One of the following three optional security level keywords can follow the 3 keyword:

auth—Enables Message Digest 5 (MD5) and Secure Hash Algorithm (SHA) packet authentication.

noauth—Specifies that the noAuthNoPriv security level applies to this host. This is the default security level for SNMPv3.

priv—Enables Data Encryption Standard (DES) packet encryption (also called "privacy").

community-string

Password-like community string is sent with the notification operation.

Note You can set this string using the snmp-server host command by itself, but Cisco recommends that you define the string using the snmp-server community command prior to using the snmp-server host command.

Note The sign (@) is used for delimiting the context information.

udp-port

(Optional) Specifies that SNMP notifications or informs are to be sent to an NMS host.

port

(Optional) UDP port number of the NMS host. The default is 162.

notification-type

(Optional) Type of notification to be sent to the host. If no type is specified, all available notifications are sent. The notification type can be one or more of the following keywords:

bgp—Sends Border Gateway Protocol (BGP) state change notifications.

calltrackerSends Call Tracker call-start/call-end notifications.

cef — Sends Cisco Express Forwarding-related notifications.

config—Sends configuration change notifications.

cpu—Sends CPU-related notifications.

director—Sends DistributedDirector-related notifications.

dspu—Sends downstream physical unit (DSPU) notifications.

eigrp—Sends Enhanced Interior Gateway Routing Protocol (EIGRP) stuck-in-active (SIA) and neighbor authentication failure notifications.

entity—Sends Entity MIB modification notifications.

envmon—Sends Cisco enterprise-specific environmental monitor notifications when an environmental threshold is exceeded.

flash—Sends flash media insertion and removal notifications.

frame-relay—Sends Frame Relay notifications.

hsrp—Sends Hot Standby Routing Protocol (HSRP) notifications.

iplocalpool—Sends IP local pool notifications.

ipmobile—Sends Mobile IP notifications.

ipsec—Sends IP Security (IPsec) notifications.

isdn—Sends ISDN notifications.

l2tun-pseudowire-status—Sends pseudowire state change notifications.

l2tun-session—Sends Layer 2 tunneling session notifications.

llc2—Sends Logical Link Control, type 2 (LLC2) notifications.

memory—Sends memory pool and memory buffer pool notifications.

mpls-ldp—Sends Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP) notifications indicating status changes in LDP sessions.

mpls-traffic-eng—Sends MPLS traffic engineering notifications indicating changes in the status of MPLS traffic engineering tunnels.

mpls-vpn—Sends MPLS VPN notifications.

ospf—Sends Open Shortest Path First (OSPF) sham-link notifications.

pim—Sends Protocol Independent Multicast (PIM) notifications.

repeater—Sends standard repeater (hub) notifications.

 

rsrb—Sends remote source-route bridging (RSRB) notifications.

rsvp—Sends Resource Reservation Protocol (RSVP) notifications.

rtr—Sends Response Time Reporter (RTR) notifications.

sdlc—Sends Synchronous Data Link Control (SDLC) notifications.

sdllc—Sends SDLC Logical Link Control (SDLLC) notifications.

snmp—Sends any enabled RFC 1157 SNMP linkUp, linkDown, authenticationFailure, warmStart, and coldStart notifications.

Note To enable RFC 2233 compliant link up/down notifications, you should use the snmp server link trap command.

srp—Sends Spatial Reuse Protocol (SRP) notifications.

stun—Sends serial tunnel (STUN) notifications.

syslog—Sends error message notifications (Cisco Syslog MIB). Specify the level of messages to be sent with the logging history level command.

tty—Sends Cisco enterprise-specific notifications when a TCP connection closes.

voice—Sends SNMP poor quality of voice traps, when used with the snmp enable peer-trap poor qov command.

vrrp—Sends Virtual Router Redundancy Protocol (VRRP) notifications.

vsimaster—Sends Virtual Switch Interface (VSI) Master notifications.

x25—Sends X.25 event notifications.


Command Default

This command is disabled. No notifications are sent.

Command Modes

Global configuration

Command History

Release
Modification

10.0

This command was introduced.

Cisco IOS Release 12 Mainline/T Train

12.0(3)T

The version 3 [auth | noauth | priv] syntax was added as part of the SNMPv3 Support feature.

The hsrp notification-type keyword was added.

The voice notification-type keyword was added.

12.1(3)T

The calltracker notification-type keyword was added for the Cisco AS5300 and AS5800 platforms.

12.2(2)T

The vrf vrf-name keyword/argument combination was added.

The ipmobile notification-type keyword was added.

Support for the vsimaster notification-type keyword was added for the Cisco 7200 and Cisco 7500 series.

12.2(4)T

The pim notification-type keyword was added.

The ipsec notification-type keyword was added.

12.2(8)T

The mpls-traffic-eng notification-type keyword was added.

The director notification-type keyword was added.

12.2(13)T

The srp notification-type keyword was added.

The mpls-ldp notification-type keyword was added.

12.3(2)T

The flash notification-type keyword was added.

The l2tun-session notification-type keyword was added.

12.3(4)T

The cpu notification-type keyword was added.

The memory notification-type keyword was added.

The ospf notification-type keyword was added.

12.3(8)T

The iplocalpool notification-type keyword was added for the Cisco 7200 and 7301 series routers.

12.3(11)T

The vrrp keyword was added.

12.3(14)T

Support for SNMP over IPv6 transport was integrated into Cisco IOS Release 12.3(14)T. Either an IP or IPv6 Internet address can be specified as the hostname argument.

The eigrp notification-type keyword was added.

Cisco IOS Release 12.0S

12.0(17)ST

The mpls-traffic-eng notification-type keyword was integrated into Cisco IOS Release 12.0(17)ST.

12.0(21)ST

The mpls-ldp notification-type keyword was integrated into Cisco IOS Release 12.0(21)ST.

12.0(22)S

All features in the Cisco IOS Release 12.0ST train were integrated into Cisco IOS Release 12.0(22)S.

The mpls-vpn notification-type keyword was added.

12.0(23)S

The l2tun-session notification-type keyword was added.

12.0(26)S

The memory notification-type keyword was added.

12.0(27)S

Support for SNMP over IPv6 transport was added. Either an IP or IPv6 Internet address can be specified as the hostname argument.

The vrf vrf-name keyword argument pair was integrated into Cisco IOS Release 12.0(27)S to support multiple Lightweight Directory Protocol (LDP) contexts for VPNs.

12.0(31)S

The l2tun-pseudowire-status notification-type keyword was added.

Release 12.2S

Modification

12.2(18)S

This command was integrated into Cisco IOS Release 12.2(18)S.

12.2(25)S

The cpu notification-type keyword was added.

The memory notification-type keyword was added.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(31)SB2

The cef notification-type keyword was added.


Usage Guidelines

If you enter this command with no keywords, the default is to send all trap types to the host. No informs will be sent to the host.

The no snmp-server host command with no keywords disables traps, but not informs, to the host. To disable informs, use the no snmp-server host informs command.


Note If the community-string is not defined using the snmp-server community command prior to using this command, the default form of the snmp-server community command will automatically be inserted into the configuration. The password (community-string) used for this automatic configuration of the snmp-server community will be the same as specified in the snmp-server host command. This automatic command insertion and use of passwords is the default behavior for Cisco IOS Release 12.0(3) and later releases.


SNMP notifications can be sent as traps or inform requests. Traps are unreliable because the receiver does not send acknowledgments when it receives traps. The sender cannot determine if the traps were received. However, a SNMP entity that receives an inform request acknowledges the message with a SNMP response protocol data unit (PDU). If the sender never receives the response, the inform request can be sent again. Thus, informs are more likely to reach their intended destination.

Compared to traps, informs consume more resources in the agent and in the network. Unlike a trap, which is discarded as soon as it is sent, an inform request must be held in memory until a response is received or the request times out. Also, traps are sent only once; an inform may be retried several times. The retries increase traffic and contribute to a higher overhead on the network.

If you do not enter a snmp-server host command, no notifications are sent. To configure the router to send SNMP notifications, you must enter at least one snmp-server host command. If you enter the command with no keywords, all trap types are enabled for the host.

To enable multiple hosts, you must issue a separate snmp-server host command for each host. You can specify multiple notification types in the command for each host.

When multiple snmp-server host commands are given for the same host and kind of notification (trap or inform), each succeeding command overwrites the previous command. Only the last snmp-server host command will be in effect. For example, if you enter an snmp-server host inform command for a host and then enter another snmp-server host inform command for the same host, the second command will replace the first.

The snmp-server host command is used in conjunction with the snmp-server enable command. Use the snmp-server enable command to specify which SNMP notifications are sent globally. For a host to receive most notifications, at least one snmp-server enable command and the snmp-server host command for that host must be enabled.

Some notification types cannot be controlled with the snmp-server enable command. For example, some notification types are always enabled and others are enabled by a different command. For example, the linkUpDown notifications are controlled by the snmp trap link-status command. These notification types do not require an snmp-server enable command.

A notification-type option's availability depends on the router type and Cisco IOS software features supported on the router. For example, the envmon notification type is available only if the environmental monitor is part of the system. To see what notification types are available on your system, use the command help ? at the end of the snmp-server host command.

The vrf keyword allows you to specify the notifications being sent to a specified IP address over a specific VRF. The VRF defines a VPN membership of a customer so data is stored using the VPN.

Regarding Notification-Type Keywords

The notification-type keywords used in the snmp-server host command do not always match the keywords used in the corresponding snmp-server enable traps command. For example, the notification keyword applicable to Multiprotocol Label Switching Protocol (MPLS) traffic engineering tunnels is specified as mpls-traffic-eng (containing two hyphens and no intervening spaces). The corresponding parameter in the snmp-server enable traps command is specified as mpls-traffic-eng (containing an intervening space and a hyphen).

This syntax difference is necessary to ensure that the command-line interface (CLI) interprets the notification-type keyword of the snmp-server host command as a unified, single-word construct, which preserves the capability of the snmp-server host command to accept multiple notification-type keywords in the command line. The snmp-server enable traps commands, however, often use two-word constructs to provide hierarchical configuration options and to maintain consistency with the command syntax of related commands. Table 20 maps some examples of snmp-server enable traps commands to the keywords used in the snmp-server host command.

Table 20 Notification Keywords and Corresponding SNMP Enable Traps Commands 

SNMP Enable Traps Command
SNMP Host Command Keyword

snmp-server enable traps l2tun session

l2tun-session

snmp-server enable traps mpls ldp

mpls-ldp

snmp-server enable traps mpls traffic-eng1

mpls-traffic-eng

snmp-server enable traps mpls vpn

mpls-vpn

1 See the Cisco IOS Multiprotocol Label Switching Command Reference for documentation of this command.


Examples

If you want to configure a unique SNMP community string for traps but prevent SNMP polling access with this string, the configuration should include an access list. The following example shows how to name a community string comaccess and number an access list 10:

Router(config)# snmp-server community comaccess ro 10 
Router(config)# snmp-server host 172.20.2.160 comaccess 
Router(config)# access-list 10 deny any 


Note The sign (@) is used as a delimiter between the community string and the context in which it is used. For example, specific VLAN information in BRIDGE-MIB may be polled using community@VLAN_ID (for example, public@100) where 100 is the VLAN number.


The following example shows how to send RFC 1157 SNMP traps to a host specified named myhost.cisco.com. Other traps are enabled, but only SNMP traps are sent because only snmp is specified in the snmp-server host command. The community string is defined as comaccess.

Router(config)# snmp-server enable traps
Router(config)# snmp-server host myhost.cisco.com comaccess snmp 

The following example shows how to send the SNMP and Cisco environmental monitor enterprise-specific traps to address 172.30.2.160 using the community string public:

Router(config)# snmp-server enable traps snmp 
Router(config)# snmp-server enable traps envmon 
Router(config)# snmp-server host 172.30.2.160 public snmp envmon 

The following example shows how to enable the router to send all traps to the host myhost.cisco.com using the community string public:

Router(config)# snmp-server enable traps 
Router(config)# snmp-server host myhost.cisco.com public 

The following example will not send traps to any host. The BGP traps are enabled for all hosts, but only the ISDN traps are enabled to be sent to a host. The community string is defined as public.

Router(config)# snmp-server enable traps bgp
Router(config)# snmp-server host myhost.cisco.com public isdn

The following example shows how to enable the router to send all inform requests to the host myhost.cisco.com using the community string public:

Router(config)# snmp-server enable traps 
Router(config)# snmp-server host myhost.cisco.com informs version 2c public 

The following example shows how to send HSRP MIB informs to the host specified by the name myhost.cisco.com. The community string is defined as public.

Router(config)# snmp-server enable traps hsrp
Router(config)# snmp-server host myhost.cisco.com informs version 2c public hsrp

The following example shows how to send all SNMP notifications to company.com over the VRF named trap-vrf using the community string public:

Router(config)# snmp-server host company.com vrf trap-vrf public

The following example shows how to configure an IPv6 SNMP notification server with the IPv6 address 2001:0DB8:0000:ABCD:1 using the community string public:

Router(config)# snmp-server host 2001:0DB8:0000:ABCD:1 version 2c public udp-port 2012

The following example shows how to specify VRRP as the protocol using the community string public:

Router(config)# snmp-server enable traps vrrp
Router(config)# snmp-server host myhost.cisco.com traps version 2c public vrrp

The following example shows how to send all Cisco Express Forwarding informs to the notification receiver with the IP address 10.56.125.47 using the community string public:

Router(config)# snmp-server enable traps cef
Router(config)# snmp-server host 10.56.125.47 informs version 2c public cef

Related Commands

Command
Description

snmp-server enable peer-trap poor qov

Enables poor quality of voice notifications for applicable calls associated with a specific voice dial peer.

snmp-server enable traps

Enables SNMP notifications (traps and informs).

snmp-server informs

Specifies inform request options.

snmp-server link trap

Enables linkUp/linkDown SNMP traps, which are compliant with RFC 2233.

snmp-server trap-source

Specifies the interface (and hence the corresponding IP address) from which a SNMP trap should originate.

snmp-server trap-timeout

Defines how often to try resending trap messages on the retransmission queue.


Feature Information for Cisco Express Forwarding—SNMP CEF-MIB Support

Table 21 lists the release history for this feature.

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 Table 21 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release. Unless noted otherwise, subsequent releases of that Cisco IOS software also support that feature.


Table 21 Feature Information for Cisco Express Forwarding—SNMP CEF-MIB Support 

Feature Name
Releases
Feature Information

Cisco Express Forwarding—SNMP CEF-MIB Support

12.2(31)SB2

The Cisco Express Forwarding—SNMP CEF-MIB Support feature introduces the CISCO-CEF-MIB that allows management applications through the use of the Simple Network Management Protocol (SNMP) to configure and monitor Cisco Express Forwarding (CEF) operational data and to provide notification when CEF encounters specific configured events. This module describes how to use the CISCO-CEF-MIB to manage and monitor objects related to CEF operation.

In 12.2(31)SB2, this feature was introduced on the Cisco 10000.

The following sections provide information about this feature:

Cisco Express Forwarding Functional Overview

CISCO-CEF-MIB Benefits

CEF Information Managed by the CISCO-CEF-MIB

CISCO-CEF-MIB Object Groups and Related Tables

Brief Description of the Tables in the CISCO-CEF-MIB

CEF Configuration and Monitoring Operations Available Through the CISCO-CEF-MIB

CISCO-CEF-MIB Notifications

Configuring the Router to Use SNMP

Configuring an SNMP Host to Receive CISCO-CEF-MIB Notifications

Configuring SNMP Notifications for Cisco Express Forwarding Events

Configuring the Throttling Interval for CISCO-CEF-MIB Inconsistency Notification

The following commands were introduced or modified by this feature: snmp mib cef throttling-interval, snmp-server enable traps cef, and snmp-server host.


Glossary

informs—A type of notification message that is more reliable than a conventional trap notification message, because the informs message notification requires acknowledgment, but a trap notification does not.

IPC—Inter-Process Communication. The protocol used by routers that support distributed packet forwarding. The Cisco IOS version of IPC provides a reliable ordered delivery of messages using an underlying platform driver transport or User Date Protocol (UDP) transport protocol. Cisco IOS software IPC services allow line cards (LCs) and the central route processor (RP) in a distributed system, such as a Cisco 7500 series router, to communicate with each other by exchanging messages from the RP to the LCs. Communication messages are also exchanged between active and standby RPs. The IPC messages include configuration commands, responses to the configuration commands, and other events that are reported by an LC to the RP.

MIB—Management Information Base. A database of network management information that is used and maintained by a network management protocol such as Simple Network Management Protocol (SNMP). The value of a MIB object can be changed or retrieved by the use of SNMP commands, usually through a network management system. MIB objects are organized in a tree structure that includes public (standard) and private (proprietary) branches.

NMS—network management station. A powerful, well-equipped computer (typically an engineering workstation) that is used by a network administrator to communicate with other devices in the network. An NMS is typically used to manage network resources, gather statistics, and perform a variety of network administration and configuration tasks. In the context of SNMP, an NMS is a device that performs SNMP queries to the SNMP agent of a managed device to retrieve or modify information.

notification—A message sent by a Simple Network Management Protocol (SNMP) agent to a network management station, console, or terminal to indicate that a significant network event has occurred. See also trap.

SNMP—Simple Network Management Protocol. A network management protocol used almost exclusively in TCP/IP networks. SNMP enables a user to monitor and control network devices, manage configurations, collect statistics, monitor performance, and ensure network security.

SNMP communities—Authentication scheme that enables an intelligent network device to validate SNMP requests.

SNMPv2c—Version 2c of the Simple Network Management Protocol. SNMPv2c supports centralized as well as distributed network management strategies and includes improvements in the Structure of Management Information (SMI), protocol operations, management architecture, and security.

trap—A message sent by an SNMP agent to a network management station, console, or terminal to indicate that a significant network event has occurred. Traps (notifications) are less reliable than inform requests, because the receiver of the trap does not send an acknowledgment of receipt; furthermore, the sender of the trap cannot determine if the trap was received. See also notification.

XDR—External Data Representation. Information elements inside Inter-Process Communication (IPC) messages in which Cisco Express Forwarding updates are encoded in distributed packet forwarding.


Note See Internetworking Terms and Acronyms for terms not included in this glossary.