SNMP Inform Request

The Simple Network Management Protocol (SNMP) Inform Requests feature allows devices to send inform requests to SNMP managers.

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Information About SNMP Inform Requests

SNMP Inform Request

The SNMP Inform Request feature supports sending inform requests. SNMP asynchronous notifications are usually sent as SNMP traps.

Traps are less reliable than informs because an acknowledgment is not sent from the receiving end when a trap is received; however, an SNMP manager that receives an inform acknowledges the message with an SNMP response PDU. If the sender does not receive a response for an inform, the inform can be sent again.

How to Configure SNMP Inform Requests

Configuring Devices to Send Traps

Perform the following task to configure the device to send traps to a host in global configuration mode:

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    snmp-server host host[version {1|2c}]community-string[udp-port port][notification-type]

    4.    snmp-server enable traps[ notification-type] [notification-option]

    5.    end


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable

    Example:
    Device> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.

     
    Step 2 configure terminal


    Example:
    Device# configure terminal
     

    Enters global configuration mode.

     
    Step 3snmp-server host host[version {1|2c}]community-string[udp-port port][notification-type]


    Example:
    Device(config)# snmp-server host 10.10.10.10 version 1 public udp-port 2012
     

    Specifies the recipient of the trap message.

     
    Step 4snmp-server enable traps[ notification-type] [notification-option]


    Example:
    Device(config)# snmp-server enable traps alarms 3
     
    Globally enables the trap production mechanism for the specified traps.
    Note   

    Some traps are not controlled by the snmp-serverenabletraps command. These traps are either enabled by default or controlled through other commands. For example, by default, SNMP link traps are sent when an interface goes up or down. For interfaces expected to go up and down during normal usage, such as ISDN interfaces, the output generated by these traps may not be useful. Use the nosnmptrapslink-status interface configuration command to disable these traps. In order for a host to receive a trap, an snmp-serverhost command must be configured for that host, and the trap must be enabled globally through the snmp-serverenabletraps command, through a different command, such as snmptrapslink-status, or by default.
     
    Step 5end


    Example:
    Device(config)# end
     

    Exits global configuration mode.

     

    Changing Inform Operation Values

    Perform the following optional task in global configuration mode to change inform operation values:

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    snmp-server informs [retries retries] [timeout seconds] [pending pending]

      4.    snmp-server trap-source interface

      5.    end


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 enable


      Example: 
      Device> enable
       

      Enables privileged EXEC mode.

      • Enter your password if prompted.

       
      Step 2 configure terminal


      Example: 
      Device# configure terminal
       

      Enters global configuration mode.

       
      Step 3 snmp-server informs [retries retries] [timeout seconds] [pending pending]


      Example: 
      Device(config)# snmp-server informs retries 10 timeout 30 pending 100
       

      Configures inform-specific operation values.

      • This example sets the maximum number of times to resend an inform, the number of seconds to wait for an acknowledgment before resending, and the maximum number of informs waiting for acknowledgments at any one time.

       
      Step 4 snmp-server trap-source interface


      Example: 
      Device(config)# snmp-server trap-source Gigabitethernet 1/2/1
       

      This example sets the IP address for the Fast Ethernet interface in slot2, port 1 as the source for all SNMP notifications.

       
      Step 5end


      Example: 
      Device(config)# end
       

      Exits global configuration mode.

       

      Configuration Examples for SNMP Inform Request

      Example: Configuring SNMP Inform Request

      The following configuration example shows how to configure the SNMP Inform Request feature for SNMPv1 or SNMPv2:

      The following example sends the SNMP and Cisco environmental monitor enterprise-specific traps to address 172.30.2.160: 

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

      The following example enables the device to send all traps to the host myhost.example.com using the community string public: 

      Device(config)# snmp-server enable traps
Device(config)# snmp-server host myhost.example.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. 

      Device(config)# snmp-server enable traps bgp
Device(config)# snmp-server host bob public isdn

      The following example enables the device to send all inform requests to the host myhost.example.com using the community string public: 

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

      Additional References

      Related Documents

      Related Topic

      Document Title

      Cisco IOS commands

      Cisco IOS Master Command List, All Releases

      SNMP commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples

      Cisco IOS SNMP Command Reference

      Cisco implementation of RFC 1724, RIP Version 2 MIB Extensions

      RIPv2 Monitoring with SNMP Using the RFC 1724 MIB Extensions feature module

      DSP Operational State Notifications for notifications to be generated when a digital signaling processor (DSP) is used

      DSP Operational State Notifications feature module

      Standards and RFCs

      Standard/RFC

      Title

      CBC-DES (DES-56) standard

      Symmetric Encryption Protocol

      STD: 58

      Structure of Management Information Version 2 (SMIv2)

      RFC 1067

      A Simple Network Management Protocol

      RFC 1091

      Telnet terminal-type option

      RFC 1098

      Simple Network Management Protocol (SNMP)

      RFC 1157

      Simple Network Management Protocol (SNMP)

      RFC 1213

      Management Information Base for Network Management of TCP/IP-based internets:MIB-II

      RFC 1215

      Convention for defining traps for use with the SNMP

      RFC 1901

      Introduction to Community-based SNMPv2

      RFC 1905

      Common Management Information Services and Protocol over TCP/IP (CMOT)

      RFC 1906

      Telnet X Display Location Option

      RFC 1908

      Simple Network Management Protocol (SNMP)

      RFC 2104

      HMAC: Keyed-Hashing for Message Authentication

      RFC 2206

      RSVP Management Information Base using SMIv2

      RFC 2213

      Integrated Services Management Information Base using SMIv2

      RFC 2214

      Integrated Services Management Information Base Guaranteed Service Extensions using SMIv2

      RFC 2271

      An Architecture for Describing SNMP Management Frameworks

      RFC 2570

      Introduction to Version 3 of the Internet-standard Network Management Framework

      RFC 2578

      Structure of Management Information Version 2 (SMIv2)

      RFC 2579

      Textual Conventions for SMIv2

      RFC 2580

      Conformance Statements for SMIv2

      RFC 2981

      Event MIB

      RFC 2982

      Distributed Management Expression MIB

      RFC 3413

      SNMPv3 Applications

      RFC 3415

      View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)

      RFC 3418

      Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)

      MIBs

      MIB

      MIBs Link

      • Circuit Interface Identification MIB

      • Cisco SNMPv2

      • Ethernet-like Interfaces MIB

      • Event MIB

      • Expression MIB Support for Delta, Wildcarding, and Aggregation

      • Interfaces Group MIB (IF-MIB)

      • Interfaces Group MIB Enhancements

      • MIB Enhancements for Universal Gateways and Access Servers

      • MSDP MIB

      • NTP MIB

      • Response Time Monitor MIB

      • Virtual Switch MIB

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

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

      Technical Assistance

      Description

      Link

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      http:/​/​www.cisco.com/​cisco/​web/​support/​index.html

      Feature Information for SNMP Inform Request

      The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

      Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to . An account on Cisco.com is not required.
      Table 1 Feature Information for SNMP Inform Request

      Feature Name

      Releases

      Feature Information

      SNMP Inform Request

      Cisco IOS XE Release 3.3SE

      The SNMP Inform Request feature supports sending inform requests. SNMP asynchronous notifications are usually sent as SNMP traps. Traps are less reliable than informs because an acknowledgment is not sent from the receiving end when a trap is received; however, an SNMP manager that receives an inform acknowledges the message with an SNMP response PDU. If the sender does not receive a response for an inform, the inform can be sent again.

      In Cisco IOS XE Release 3.3SE, support was added for the Cisco Catalyst 3650 Series Switches and Cisco Catalyst 3850 Series Switches.