Cisco Nexus 9000 Series NX-OS System Management Configuration Guide, Release 6.x

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• Preface
• New and Changed Information
• Overview
• Configuring NTP
• Configuring CDP
• Configuring System Message Logging
• Configuring Smart Call Home
• Configuring Rollback
• Configuring Session Manager
• Configuring the Scheduler
• Configuring SNMP
• Configuring RMON
• Configuring Online Diagnostics
• Configuring the Embedded Event Manager
• Configuring Onboard Failure Logging
• Configuring SPAN
• Configuring ERSPAN
• Configuring LLDP
• Performing Software Maintenance Upgrades
• IETF RFCs supported by Cisco NX-OS System Management
• Embedded Event Manager System Events and Configuration Examples
• Configuration Limits for Cisco NX-OS System Management

Book Title

Cisco Nexus 9000 Series NX-OS System Management Configuration Guide, Release 6.x

Configuring SNMP

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Results

Chapter: Configuring SNMP

• Configuring SNMP
• About SNMP
  • SNMP Functional Overview
  • SNMP Notifications
  • SNMPv3
    • Security Models and Levels for SNMPv1, v2, v3
    • User-Based Security Model
    • CLI and SNMP User Synchronization
    • Group-Based SNMP Access
    • Configuring SNMP Users
    • Enforcing SNMP Message Encryption
    • Assigning SNMPv3 Users to Multiple Roles
    • Creating SNMP Communities
    • Filtering SNMP Requests
    • Configuring SNMP Notification Receivers
    • Configuring a Source Interface for SNMP Notifications
    • Configuring the Notification Target User
    • Configuring SNMP Notification Receivers with VRFs
    • Configuring SNMP to Send Traps Using an Inband Port
    • Enabling SNMP Notifications
    • Disabling Link Notifications on an Interface
    • Displaying SNMP ifIndex for an Interface
    • Enabling a One-Time Authentication for SNMP over TCP
    • Assigning SNMP Device Contact and Location Information
    • Configuring the Context to Network Entity Mapping
    • Disabling SNMP
    • Modifying the AAA Synchronization Time
    • Related Documents
    • RFCs
    • MIBs

    Configuring SNMP

    This chapter describes how to configure the SNMP feature on Cisco NX-OS devices.

    This chapter contains the following sections:

    About SNMP

    The Simple Network Management Protocol (SNMP) is an application-layer protocol that provides a message format for communication between SNMP managers and agents. SNMP provides a standardized framework and a common language used for the monitoring and management of devices in a network.

    SNMP Functional Overview

    The SNMP framework consists of three parts:

    • An SNMP manager—The system used to control and monitor the activities of network devices using SNMP.
    • An SNMP agent—The software component within the managed device that maintains the data for the device and reports these data, as needed, to managing systems. The Cisco Nexus device supports the agent and MIB. To enable the SNMP agent, you must define the relationship between the manager and the agent.
    • A managed information base (MIB)—The collection of managed objects on the SNMP agent

    SNMP is defined in RFCs 3411 to 3418.

    The device supports SNMPv1, SNMPv2c, and SNMPv3. Both SNMPv1 and SNMPv2c use a community-based form of security.

    Cisco NX-OS supports SNMP over IPv6.

    SNMP Notifications

    A key feature of SNMP is the ability to generate notifications from an SNMP agent. These notifications do not require that requests be sent from the SNMP manager. Notifications can indicate improper user authentication, restarts, the closing of a connection, loss of connection to a neighbor router, or other significant events.

    Cisco NX-OS generates SNMP notifications as either traps or informs. A trap is an asynchronous, unacknowledged message sent from the agent to the SNMP managers listed in the host receiver table. Informs are asynchronous messages sent from the SNMP agent to the SNMP manager which the manager must acknowledge receipt of.

    Traps are less reliable than informs because the SNMP manager does not send any acknowledgment when it receives a trap. The device cannot determine if the trap was received. An SNMP manager that receives an inform request acknowledges the message with an SNMP response protocol data unit (PDU). If the device never receives a response, it can send the inform request again.

    You can configure Cisco NX-OS to send notifications to multiple host receivers.

    The following table lists the SNMP traps that are enabled by default.

    Trap Type	Description
    generic	: coldStart
    entity	: entity_fan_status_change
    entity	: entity_mib_change
    entity	: entity_module_status_change
    entity	: entity_module_inserted
    entity	: entity_module_removed
    entity	: entity_power_out_change
    entity	: entity_power_status_change
    entity	: entity_unrecognised_module
    link	: cErrDisableInterfaceEventRev1
    link	: cieLinkDown
    link	: cieLinkUp
    link	: cmn-mac-move-notification
    link	: delayed-link-state-change
    link	: extended-linkDown
    link	: extended-linkUp
    link	: linkDown
    link	: linkUp
    rf	: redundancy_framework
    license	: notify-license-expiry
    license	: notify-no-license-for-feature
    license	: notify-licensefile-missing
    license	: notify-license-expiry-warning
    upgrade	: UpgradeOpNotifyOnCompletion
    upgrade	: UpgradeJobStatusNotify
    entity	: entity_sensor
    rmon	: fallingAlarm
    rmon	: hcRisingAlarm
    rmon	: hcFallingAlarm
    rmon	: risingAlarm

    SNMPv3

    SNMPv3 provides secure access to devices by a combination of authenticating and encrypting frames over the network. The security features provided in SNMPv3 are the following:

    • Message integrity—Ensures that a packet has not been tampered with in-transit.
    • Authentication—Determines the message is from a valid source.
    • Encryption—Scrambles the packet contents to prevent it from being seen by unauthorized sources.

    SNMPv3 provides for both security models and security levels. A security model is an authentication strategy that is set up for a user and the role in which the user resides. A security level is the permitted level of security within a security model. A combination of a security model and a security level determines which security mechanism is employed when handling an SNMP packet.

    Security Models and Levels for SNMPv1, v2, v3

    The security level determines if an SNMP message needs to be protected from disclosure and if the message needs to be authenticated. The various security levels that exist within a security model are as follows:

    • noAuthNoPriv—Security level that does not provide authentication or encryption. This level is not supported for SNMPv3.
    • authNoPriv—Security level that provides authentication but does not provide encryption.
    • authPriv—Security level that provides both authentication and encryption.

    Three security models are available: SNMPv1, SNMPv2c, and SNMPv3. The security model combined with the security level determine the security mechanism applied when the SNMP message is processed. The following table identifies what the combinations of security models and levels mean.

    Uses a community string match for authentication.

    Uses a community string match for authentication.

    HMAC-MD5, or HMAC-SHA

    Provides authentication based on the Hash-Based Message Authentication Code (HMAC) Message Digest 5 (MD5) algorithm or the HMAC Secure Hash Algorithm (SHA).

    HMAC-MD5, or HMAC-SHA

    Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides Data Encryption Standard (DES) 56-bit encryption in addition to authentication based on the Cipher Block Chaining (CBC) DES (DES-56) standard.

    User-Based Security Model

    The SNMPv3 User-Based Security Model (USM) refers to SNMP message-level security and offers the following services:

    • Message integrity—Ensures that messages have not been altered or destroyed in an unauthorized manner and that data sequences have not been altered to an extent greater than can occur nonmaliciously.
    • Message origin authentication—Ensures that the claimed identity of the user on whose behalf received data was originated is confirmed.
    • Message confidentiality—Ensures that information is not made available or disclosed to unauthorized individuals, entities, or processes.

    SNMPv3 authorizes management operations only by configured users and encrypts SNMP messages.

    Cisco NX-OS uses three authentication protocols for SNMPv3:

    • HMAC-MD5-96 authentication protocol
    • HMAC-SHA-96 authentication protocol

    Cisco NX-OS uses Advanced Encryption Standard (AES) as one of the privacy protocols for SNMPv3 message encryption and conforms with RFC 3826.

    The priv option offers a choice of DES or 128-bit AES encryption for SNMP security encryption. The priv option and the aes-128 token indicate that this privacy password is for generating a 128-bit AES key. The AES priv password can have a minimum of eight characters. If the passphrases are specified in clear text, you can specify a maximum of 64 case-sensitive, alphanumeric characters. If you use the localized key, you can specify a maximum of 130 characters.

    For an SNMPv3 operation using the external AAA server, you must use AES for the privacy protocol in the user configuration on the external AAA server.

    CLI and SNMP User Synchronization

    SNMPv3 user management can be centralized at the Access Authentication and Accounting (AAA) server level. This centralized user management allows the SNMP agent in Cisco NX-OS to leverage the user authentication service of the AAA server. Once user authentication is verified, the SNMP PDUs are processed further. Additionally, the AAA server is also used to store user group names. SNMP uses the group names to apply the access/role policy that is locally available in the switch.

    Any configuration changes made to the user group, role, or password results in database synchronization for both SNMP and AAA.

    Cisco NX-OS synchronizes the user configuration in the following ways:

    • The authentication passphrase specified in the snmp-server user command becomes the password for the CLI user.
    • The password specified in the username command becomes the authentication and privacy passphrases for the SNMP user.
    • If you create or delete a user using either SNMP or the CLI, the user is created or deleted for both SNMP and the CLI.
    • User-role mapping changes are synchronized in SNMP and the CLI.
    • Role changes (deletions or modifications) from the CLI are synchronized to SNMP.

    When you configure a passphrase/password in localized key/encrypted format, Cisco NX-OS does not synchronize the user information (passwords, roles, and so on).

    Cisco NX-OS holds the synchronized user configuration for 60 minutes by default.

    Group-Based SNMP Access

    Because group is a standard SNMP term used industry-wide, we refer to roles as groups in this SNMP section.

    SNMP access rights are organized by groups. Each group in SNMP is similar to a role through the CLI. Each group is defined with read access or read-write access.

    You can begin communicating with the agent once your username is created, your roles are set up by your administrator, and you are added to the roles.

    SNMP and Embedded Event Manager

    The Embedded Event Manager (EEM) feature monitors events, including SNMP MIB objects, and triggers an action based on these events. One of the actions could be to send an SNMP notification. EEM sends the cEventMgrPolicyEvent of CISCO-EMBEDDED-EVENT-MGR-MIB as the SNMP notification.

    Multiple Instance Support

    A device can support multiple instances of a logical network entity, such as protocol instances or virtual routing and forwarding (VRF) instances. Most existing MIBs cannot distinguish between these multiple logical network entities. For example, the original OSPF-MIB assumes a single protocol instance on a device, but you can now configure multiple OSPF instances on a device.

    SNMPv3 uses contexts to distinguish between these multiple instances. An SNMP context is a collection of management information that you can access through the SNMP agent. A device can support multiple contexts for different logical network entities. An SNMP context allows the SNMP manager to access one of the multiple instances of a MIB module supported on the device for the different logical network entities.

    Cisco NX-OS supports the CISCO-CONTEXT-MAPPING-MIB to map between SNMP contexts and logical network entities. You can associate an SNMP context to a VRF, protocol instance, or topology.

    SNMPv3 supports contexts with the contextName field of the SNMPv3 PDU. You can map this contextName field to a particular protocol instance or VRF.

    For SNMPv2c, you can map the SNMP community to a context using the snmpCommunityContextName MIB object in the SNMP-COMMUNITY-MIB (RFC 3584). You can then map this snmpCommunityContextName to a particular protocol instance or VRF using the CISCO-CONTEXT-MAPPING-MIB or the CLI.

    High Availability for SNMP

    Cisco NX-OS supports stateless restarts for SNMP. After a reboot or supervisor switchover, Cisco NX-OS applies the running configuration.

    Virtualization Support for SNMP

    Cisco NX-OS supports one instance of the SNMP. SNMP supports multiple MIB module instances and maps them to logical network entities.

    SNMP is also VRF aware. You can configure SNMP to use a particular VRF to reach the SNMP notification host receiver. You can also configure SNMP to filter notifications to an SNMP host receiver based on the VRF where the notification occurred.

    Guidelines and Limitations for SNMP

    SNMP has the following configuration guidelines and limitations:

    • Commands configured using SNMP SET should be deleted using SNMP SET only. Commands configured using Command Line Interface(CLI) or NX-API should be deleted using CLI or NX-API only.
    • Access control list (ACLs) can be applied only to local SNMPv3 users configured on the switch. ACLs cannot be applied to remote SNMPv3 users stored on Authentication, Authorization, and Accounting (AAA) servers.
    • Cisco NX-OS supports read-only access to some SNMP MIBs. See the Cisco NX-OS MIB support list at the following URL for more information:https://cisco.github.io/cisco-mibs/supportlists/nexus9000/Nexus9000MIBSupportList.html
    • Cisco NX-OS does not support the SNMPv3 noAuthNoPriv security level.
    • Special characters @ and % are not allowed in the SNMP community string.
    • The default SNMP PDU value is 1500 bytes. The SNMP agent drops any response PDU that is greater than 1500 bytes, causing the SNMP request to fail. To receive MIB data values larger than 1500 bytes, use the snmp-server packetsize command to reconfigure the packet size. The valid byte-count range is from 484 to 17382. When a GETBULK response exceeds the packet size, the data can get truncated.
    • You must use either the CLI or SNMP to configure a feature on your switch. Do not configure a feature using both interfaces to the switch.
    • Using cefcFanTrayOperStatus snmpwalk on an individual fan OID tree where the fan is not populated in chassis, can return a response for next OID entry in the tree. To prevent this behavior, use the -CI option in snmpwalk. The behavior is not seen when polling parent OID, or when using getmany.

    Default Settings for SNMP

    The following table lists the default settings for SNMP parameters.

    Parameters	Default
    License notifications	Enabled

    Configuring SNMP

    Configuring SNMP Users

    You can configure a user for SNMP.

    Procedure

    Example:

    switch# configure terminal switch(config)#

    Enters global configuration mode.

    (Optional) show snmp user

    Example:

    switch(config)# show snmp user

    Displays information about one or more SNMP users.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Enforcing SNMP Message Encryption

    You can configure SNMP to require authentication or encryption for incoming requests. By default, the SNMP agent accepts SNMPv3 messages without authentication and encryption. When you enforce privacy, Cisco NX-OS responds with an authorization error for any SNMPv3 PDU request using a security level parameter of either noAuthNoPriv or authNoPriv .

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server user name enforcePriv

    Example:

    switch(config)# snmp-server user Admin enforcePriv 

    Enforces SNMP message encryption for this user.

    Example:

    switch(config)# snmp-server globalEnforcePriv 

    Enforces SNMP message encryption for all users.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Assigning SNMPv3 Users to Multiple Roles

    After you configure an SNMP user, you can assign multiple roles for the user.

    Only users belonging to a network-admin role can assign roles to other users.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server user name group

    Example:

    switch(config)# snmp-server user Admin superuser 

    Associates this SNMP user with the configured user role.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Creating SNMP Communities

    You can create SNMP communities for SNMPv1 or SNMPv2c.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server community name

    Example:

    switch(config)# snmp-server community public ro 

    Creates an SNMP community string.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Filtering SNMP Requests

    ACL with SNMPv3 user is not supported. You can assign an access control list (ACL) to an SNMPv2 community to filter SNMP requests. If the assigned ACL allows the incoming request packet, SNMP processes the request. If the ACL denies the request, SNMP drops the request and sends a system message.

    Create the ACL with the following parameters:

    • Source IP address
    • Destination IP address
    • Source port
    • Destination port
    • Protocol (UDP or TCP)

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server community name [ use-ipv4acl acl-name ]

    Example:

    switch(config)# snmp-server community public use-ipv4acl myacl 

    Assigns an IPv4 ACL to an SNMPv2 community to filter SNMP requests.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Configuring SNMP Notification Receivers

    You can configure Cisco NX-OS to generate SNMP notifications to multiple host receivers.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server host ip-address traps version 1 community [ udp_port number ]

    Example:

    switch(config)# snmp-server host 192.0.2.1 traps version 1 public 

    Configures a host receiver for SNMPv1 traps. The ip-address can be an IPv4 or IPv6 address. The community can be any alphanumeric string up to 255 characters. The UDP port number range is from 0 to 65535.

    snmp-server host ip-address < traps | informs >version 2c community [ udp_port number ]

    Example:

    switch(config)# snmp-server host 192.0.2.1 informs version 2c public 

    Configures a host receiver for SNMPv2c traps or informs. The ip-address can be an IPv4 or IPv6 address. The community can be any alphanumeric string up to 255 characters. The UDP port number range is from 0 to 65535.

    snmp-server host ip-address < traps | informs >version 3 < auth | noauth | priv >username [ udp_port number ]

    Example:

    switch(config)# snmp-server host 192.0.2.1 informs version 3 auth NMS 

    The SNMP manager must know the user credentials (authKey/PrivKey) based on the SNMP engine ID of the Cisco NX-OS device to authenticate and decrypt the SNMPv3 messages.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Configuring a Source Interface for SNMP Notifications

    You can configure SNMP to use the IP address of an interface as the source IP address for notifications. When a notification is generated, its source IP address is based on the IP address of this configured interface.

    You can configure a source interface as follows:

    • All notifications sent to all SNMP notification receivers.
    • All notifications sent to a specific SNMP notification receiver. This configuration overrides the global source interface configuration.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server host ip-address source-interface if-type if-number traps version 2c name

    Example:

    snmp-server host 192.0.2.1 source-interface ethernet 2/1 traps version 2c public 

    (Optional) Send Traps messages to this host.

    The traps version is the SNMP version to use for notification messages. 2c indicates that SNMPv2c is to be used.

    snmp-server host ip-address source-interface if-type if-number use-vrf vrf-name

    Example:

    snmp-server host 192.0.2.1 source-interface ethernet 2/1 use-vrf default 

    Configures SNMP to use the selected VRF to communicate with the host receiver. The ip-address can be an IPv4 or IPv6 address. The VRF name can be any alphanumeric string up to 32 characters.

    This command does not remove the host configuration.

    snmp-server host ip-address source-interface if-type if-number [ udp_port number ]

    Example:

    switch(config)# snmp-server host 192.0.2.1 source-interface ethernet 2/1 

    Configures a host receiver for SNMPv2c traps or informs. The ip-address can be an IPv4 or IPv6 address. Use ? to determine the supported interface types. The UDP port number range is from 0 to 65535.

    This configuration overrides the global source interface configuration.

    snmp-server source-interface < traps | informs >if-type if-number

    Example:

    switch(config)# snmp-server source-interface traps ethernet 2/1 

    Configures a source interface for sending out SNMPv2c traps or informs. Use ? to determine the supported interface types.

    show snmp source-interface

    Example:

    switch(config)# show snmp source-interface 

    Displays information about configured source interfaces.

    Configuring the Notification Target User

    You must configure a notification target user on the device to send SNMPv3 inform notifications to a notification host receiver.

    Cisco NX-OS uses the credentials of the notification target user to encrypt the SNMPv3 inform notification messages to the configured notification host receiver.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server user name [ auth < md5 | sha | sha-256 >passphrase [ auto ] [ priv [ aes-128 ] passphrase ] [ engineID id ]

    Example:

    switch(config)# snmp-server user NMS auth sha abcd1234 priv abcdefgh engineID 00:00:00:63:00:01:00:10:20:15:10:03 

    Configures the notification target user with the specified engine ID for the notification host receiver. The engine ID format is a 12-digit colon-separated decimal number.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Configuring SNMP Notification Receivers with VRFs

    SNMP adds entries into the cExtSnmpTargetVrfTable of the CISCO-SNMP-TARGET-EXT-MIB when you configure the VRF reachability and filtering options for an SNMP notification receiver.

    You must configure the host before configuring the VRF reachability or filtering options.

    You can configure Cisco NX-OS to use a configured VRF to reach the host receiver or to filter notifications based on the VRF in which the notification occurred.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    [ no ] snmp-server host ip-address use-vrf vrf-name [ udp_port number ]

    Example:

    switch(config)# snmp-server host 192.0.2.1 use-vrf Blue 

    Configures SNMP to use the selected VRF to communicate with the host receiver. The ip-address can be an IPv4 or IPv6 address. The VRF name can be any alphanumeric string up to 255 characters. The UDP port number range is from 0 to 65535. This command adds an entry into the ExtSnmpTargetVrfTable of the CISCO-SNMP-TARGET-EXT-MB.

    The no form of this command removes the VRF reachability information for the configured host and removes the entry from the ExtSnmpTargetVrfTable of the CISCO-SNMP-TARGET-EXT-MB.

    This command does not remove the host configuration.

    [ no ] snmp-server host ip-address filter-vrf vrf-name [ udp_port number ]

    Example:

    switch(config)# snmp-server host 192.0.2.1 filter-vrf Red 

    Filters notifications to the notification host receiver based on the configured VRF. The ip-address can be an IPv4 or IPv6 address. The VRF name can be any alphanumeric string up to 255 characters. The UDP port number range is from 0 to 65535.

    This command adds an entry into the ExtSnmpTargetVrfTable of the CISCO-SNMP-TARGET-EXT-MB.

    The no form of this command removes the VRF filter information for the configured host and removes the entry from the ExtSnmpTargetVrfTable of the CISCO-SNMP-TARGET-EXT-MB.

    This command does not remove the host configuration.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Configuring SNMP to Send Traps Using an Inband Port

    You can configure SNMP to send traps using an inband port. To do so, you must configure the source interface (at the global or host level) and the VRF used to send the traps.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server source-interface traps if-type if-number

    Example:

    switch(config)# snmp-server source-interface traps ethernet 1/2 

    Globally configures a source interface for sending out SNMP traps. Use ? to determine the supported interface types.

    You can configure the source interface at the global level or at a host level. When the source interface is configured globally, any new host configuration uses the global configuration to send the traps.

    (Optional) show snmp source-interface

    Example:

    switch(config)# show snmp source-interface 

    Displays information about configured source interfaces.

    snmp-server host ip-address use-vrf vrf-name [ udp_port number ]

    Example:

    switch(config)# snmp-server host 171.71.48.164 use-vrf default 

    Configures SNMP to use the selected VRF to communicate with the host receiver. The ip-address can be an IPv4 or IPv6 address. The VRF name can be any alphanumeric string up to 255 characters. The UDP port number range is from 0 to 65535. This command adds an entry into the ExtSnmpTargetVrfTable of the CISCO-SNMP-TARGET-EXT-MB.

    (Optional) show snmp host

    Example:

    switch(config)# show snmp host 

    Displays information about configured SNMP hosts.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Enabling SNMP Notifications

    You can enable or disable notifications. If you do not specify a notification name, Cisco NX-OS enables all notifications except BGP, EIGRP, and OSPF notifications.

    The following table lists the commands that enable the notifications for Cisco NX-OS MIBs.

    All notifications (except BGP, EIGRP, and OSPF)

    snmp-server enable traps

    snmp-server enable traps aaa

    snmp-server enable traps aaa server-state-change

    snmp-server enable traps bgp

    snmp-server enable traps callhome

    snmp-server enable traps callhome event-notify

    snmp-server enable traps callhome smtp-send-fail

    snmp-server enable traps config

    snmp-server enable traps config ccmCLIRunningConfigChanged

    snmp-server enable traps eigrp [ tag ]

    snmp-server enable traps link cerrDisableInterfaceEventRev1

    snmp-server enable traps entity

    snmp-server enable traps entity entity_fan_status_change

    snmp-server enable traps entity entity_mib_change

    snmp-server enable traps entity entity_module_inserted

    snmp-server enable traps entity entity_module_removed

    snmp-server enable traps entity entity_module_status_change

    snmp-server enable traps entity entity_power_out_change

    snmp-server enable traps entity entity_power_status_change

    snmp-server enable traps entity entity_unrecognised_module

    snmp-server enable traps feature-control

    snmp-server enable traps feature-control FeatureOpStatusChange

    snmp-server enable traps hsrp

    snmp-server enable traps hsrp state-change

    snmp-server enable traps license

    snmp-server enable traps license notify-license-expiry

    snmp-server enable traps license notify-license-expiry-warning

    snmp-server enable traps license notify-licensefile-missing

    snmp-server enable traps license notify-no-license-for-feature

    snmp-server enable traps link

    snmp-server enable traps link IETF-extended-linkDown

    snmp-server enable traps link IETF-extended-linkUp

    snmp-server enable traps link cisco-extended-linkDown

    snmp-server enable traps link cisco-extended-linkUp

    snmp-server enable traps link linkDown

    snmp-server enable traps link Up

    snmp-server enable traps ospf [ tag ]

    snmp-server enable traps ospf lsa

    snmp-server enable traps ospf rate-limit rate

    snmp-server enable traps rf

    snmp-server enable traps rf redundancy_framework

    snmp-server enable traps rmon

    snmp-server enable traps rmon fallingAlarm

    snmp-server enable traps rmon hcFallingAlarm

    snmp-server enable traps rmon hcRisingAlarm

    snmp-server enable traps rmon risingAlarm

    snmp-server enable traps snmp

    snmp-server enable traps snmp authentication

    storm-control action trap

    snmp-server enable traps stpx stpxMstInconsistencyUpdate

    snmp-server enable traps bridge

    snmp-server enable traps bridge newroot

    snmp-server enable traps bridge topologychange

    snmp-server enable traps stpx

    snmp-server enable traps stpx inconsistency

    snmp-server enable traps stpx loop-inconsistency

    snmp-server enable traps stpx root-inconsistency

    snmp-server enable traps sysmgr

    snmp-server enable traps sysmgr cseFailSwCoreNotifyExtended

    snmp-server enable traps upgrade

    snmp-server enable traps upgrade UpgradeJobStatusNotify

    snmp-server enable traps upgrade UpgradeOpNotifyOnCompletion

    snmp-server enable traps vtp

    snmp-server enable traps vtp notifs

    snmp-server enable traps vtp vlancreate

    snmp-server enable traps vtp vlandelete

    Use the following commands in the configuration mode shown to enable the specified notification:

    Example:

    switch(config)# snmp-server enable traps

    Enables all SNMP notifications.

    Example:

    switch(config)# snmp-server enable traps aaa

    Enables the AAA SNMP notifications. Optionally, enables the following specific notifications:

    Example:

    switch(config)# snmp-server enable traps bgp

    Enables Border Gateway Protocol (BGP) SNMP notifications.

    Example:

    switch(config)# snmp-server enable traps bridge

    Enables STP bridge SNMP notifications. Optionally, enables the following specific notifications:

    • newroot —Enables STP new root bridge notifications.
    • topologychange —Enables STP bridge topology-change notifications.

    Example:

    switch(config)# snmp-server enable traps callhome

    Enables Call Home notifications. Optionally, enables the following specific notifications:

    • event-notify —Enables Call Home external event notifications.
    • smtp-send-fail —Enables Simple Mail Transfer Protocol (SMTP) message send fail notifications.

    Example:

    switch(config)# snmp-server enable traps config

    Enables SNMP notifications for configuration changes.

    • ccmCLIRunningConfigChanged —Enables SNMP notifications for configuration changes in the running or startup configuration.

    Example:

    switch(config)# snmp-server enable traps eigrp

    Enables CISCO-EIGRP-MIB SNMP notifications.

    Example:

    switch(config)# snmp-server enable traps entity

    Enables ENTITY-MIB SNMP notifications. Optionally, enables the following specific notifications:

    • entity_fan_status_change —Enables entity fan status-change notifications.
    • entity_mib_change —Enables entity MIB change notifications.
    • entity_module_inserted —Enables entity module inserted notifications.
    • entity_module_removed —Enables entity module removed notifications.
    • entity_module_status_change —Enables entity module status-change notifications.
    • entity_power_out_change —Enables entity power-out change notifications.
    • entity_power_status_change —Enables entity power status-change notifications.
    • entity_unrecognised_module —Enables entity unrecognized module notifications.

    Example:

    switch(config)# snmp-server enable traps feature-control

    Enables feature-control SNMP notifications. Optionally, enables the following specific notifications:

    • FeatureOpStatusChange —Enables feature operation status-change notifications.

    Example:

    switch(config)# snmp-server enable traps hsrp

    Enables CISCO-HSRP-MIB SNMP notifications. Optionally, enables the following specific notifications:

    • state-change —Enables HSRP state-change notifications.

    Example:

    switch(config)# snmp-server enable traps license

    Enables ENTITY-MIB SNMP notifications. Optionally, enables the following specific notifications:

    • notify-license-expiry —Enables license expiry notifications.
    • notify-license-expiry-warning —Enables license expiry warning notifications.
    • notify-licensefile-missing —Enables license file-missing notifications.
    • notify-no-license-for-feature —Enables no-license-installed-for-feature notifications.

    Example:

    switch(config)# snmp-server enable traps link

    Enables IF-MIB link notifications. Optionally, enable the following specific notifications:

    • IETF-extended-linkDown —Enables Cisco extended link state down notifications.
    • IETF-extended-linkUp —Enables Cisco extended link state up notifications.
    • cmn-mac-move-notification —Enables MAC address move notifications.
    • cisco-extended-linkDown —Enables Internet Engineering Task Force (IETF) extended link state down notifications.
    • cisco-extended-linkUp —Enables Internet Engineering Task Force (IETF) extended link state up notifications.
    • linkDown —Enables IETF link state down notifications.
    • linkUp —Enables IETF link state up notifications.

    Example:

    switch(config)# snmp-server enable traps ospf

    Enables Open Shortest Path First (OSPF) notifications. Optionally, enables the following specific notifications:

    • lsa —Enables OSPF link state advertisement (LSA) notifications.

    Example:

    switch(config)# snmp-server enable traps rf

    Enables redundancy framework (RF) SNMP notifications. Optionally, enables the following specific notifications:

    • redundancy-framework —Enables RF supervisor switchover MIB notifications.

    Example:

    switch(config)# snmp-server enable traps rmon

    Enables remote monitoring (RMON) SNMP notifications. Optionally, enables the following specific notifications:

    • fallingAlarm —Enables RMON falling alarm notifications.
    • hcFallingAlarm —Enables RMON high-capacity falling alarm notifications.
    • hcRisingAlarm —Enables RMON high-capacity rising alarm notifications.
    • risingAlarm —Enables RMON rising alarm notifications.

    Example:

    switch(config)# snmp-server enable traps snmp

    Enables general SNMP notifications. Optionally, enables the following specific notifications:

    • authentication —Enables SNMP authentication notifications.

    Example:

    switch(config)# snmp-server enable traps stpx

    Enables SNMP STPX notifications. Optionally, enables the following specific notifications:

    • inconsistency —Enables SNMP STPX MIB inconsistency update notifications.
    • loop-inconsistency —Enables SNMP STPX MIB loop-inconsistency update notifications.
    • root-inconsistency —Enables SNMP STPX MIB root-inconsistency update notifications.

    Example:

    switch(config)# snmp-server enable traps syslog

    Sends syslog messages as traps to the defined SNMP host. Optionally, enables the following specific notifications:

    • message-generated —Enables software log message generated notifications.

    Example:

    switch(config)# snmp-server enable traps sysmgr

    Enables software change notifications. Optionally, enables the following specific notifications:

    • cseFailSwCoreNotifyExtended —Enables software core notifications.

    Example:

    switch(config)# snmp-server enable traps upgrade

    Enables upgrade notifications. Optionally, enables the following specific notifications:

    • UpgradeJobStatusNotify —Enables upgrade job status notifications.
    • UpgradeOpNotifyOnCompletion —Enables upgrade global status notifications.

    Example:

    switch(config)# snmp-server enable traps vtp

    Enables VTP notifications. Optionally, enables the following specific notifications:

    • notifs —Enables VTP notifications.
    • vlancreate —Enables VLAN creation notifications.
    • vlandelete —Enables VLAN deletion notifications.

    Example:

    switch(config-if)# storm-control action traps 

    Enables traffic storm control notifications when the traffic storm control limit is reached.

    Disabling Link Notifications on an Interface

    You can disable linkUp and linkDown notifications on an individual interface. You can use this limit notifications on flapping interface (an interface that transitions between up and down repeatedly).

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    interface type slot / port

    Example:

    switch(config)# interface ethernet 2/2 

    Disables SNMP link-state traps for the interface. This command is enabled by default.

    no snmp trap link-status

    Example:

    switch(config-if)# no snmp trap link-status 

    Disables SNMP link-state traps for the interface. This command is enabled by default.

    (Optional) copy running-config startup-config

    Example:

    switch(config-if)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Displaying SNMP ifIndex for an Interface

    The SNMP ifIndex is used across multiple SNMP MIBs to link related interface information.

    Procedure

    show interface snmp-ifindex

    Example:

    switch# show interface snmp-ifindex | grep -i Eth12/1 Eth12/1 441974784 (0x1a580000) 

    Displays the persistent SNMP ifIndex value from the IF-MIB for all interfaces. Optionally, use the | keyword and the grep keyword to search for a particular interface in the output.

    Enabling a One-Time Authentication for SNMP over TCP

    You can enable a one-time authentication for SNMP over a TCP session.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server tcp-session [ auth ]

    Example:

    switch(config)# snmp-server tcp-session 

    Enables a one-time authentication for SNMP over a TCP session. The default is disabled.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Assigning SNMP Device Contact and Location Information

    You can assign the device contact information, which is limited to 32 characters (without spaces) and the device location.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server contact name

    Example:

    switch(config)# snmp-server contact Admin 

    Configures sysContact, which is the SNMP contact name.

    snmp-server location name

    Example:

    switch(config)# snmp-server location Lab-7 

    Configures sysLocation, which is the SNMP location.

    (Optional) show snmp

    Example:

    switch(config)# show snmp 

    Displays information about one or more destination profiles.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Configuring the Context to Network Entity Mapping

    You can configure an SNMP context to map to a logical network entity, such as a protocol instance or VRF.

    Before you begin

    Determine the logical network entity instance. For more information on VRFs and protocol instances, see the Cisco Nexus 9000 Series NX-OS Unicast Routing Configuration Guide or the Cisco Nexus 9000 Series NX-OS Multicast Routing Configuration Guide.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    [ no ] snmp-server context context-name [ instance instance-name ] [ vrf vrf-name ] [ topology topology-name ]

    Example:

    switch(config)# snmp-server context public1 vrf red 

    Maps an SNMP context to a protocol instance, VRF, or topology. The names can be any alphanumeric string up to 32 characters.

    The no option deletes the mapping between an SNMP context and a protocol instance, VRF, or topology.

    (Optional) snmp-server mib community-map community-name context context-name

    Example:

    switch(config)# snmp-server mib community-map public context public1

    Maps an SNMPv2c community to an SNMP context. The names can be any alphanumeric string up to 32 characters.

    (Optional) show snmp context

    Example:

    switch(config)# show snmp context

    Displays information about one or more SNMP contexts.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Disabling SNMP

    You can disable SNMP on the device.

    Procedure

    Example:

    switch# configure terminal switch(config)#

    Enters global configuration mode.

    no snmp-server protocol enable

    Example:

    switch(config)# no snmp-server protocol enable

    Disables SNMP. SNMP is enabled by default.

    You cannot disable SNMPv1 without disabling SNMPv2. If you want to disable SNMPv1, then configure only SNMPv3, or disable SNMP entirely.

    Modifying the AAA Synchronization Time

    You can modify how long Cisco NX-OS holds the synchronized user configuration.

    Procedure

    Example:

    switch# configure terminal switch(config)# 

    Enters global configuration mode.

    snmp-server aaa-user cache-timeout seconds

    Example:

    switch(config)# snmp-server aaa-user cache-timeout 1200 

    Configures how long the AAA synchronized user configuration stays in the local cache. The range is from 1 to 86400 seconds. The default is 3600.

    (Optional) copy running-config startup-config

    Example:

    switch(config)# copy running-config startup-config 

    Copies the running configuration to the startup configuration.

    Verifying SNMP Configuration

    To display SNMP configuration information, perform one of the following tasks:

    Displays the SNMP ifIndex value for all interfaces (from IF-MIB).

    Displays the SNMP running configuration.

    Beginning with 9.3(8) release, SNMPv3 users under show run will be represented in SALT format instead of hash.

    Displays the SNMP status.

    Displays the SNMP community strings.

    If the name of the SNMP context in the snmp-server mib community-map command is more than 11 characters, the output of the show snmp community command is displayed in a vertical format instead of a tabular format.

    Displays the SNMP context mapping.

    Displays the SNMP engineID.

    Displays SNMP roles.

    Displays information about configured SNMP hosts.

    Displays SNMP sessions.

    Displays information about configured source interfaces.

    Displays the SNMP notifications enabled or disabled.

    Displays SNMPv3 users.

    Configuration Examples for SNMP

    This example shows how to configure Cisco NX-OS to send the Cisco linkUp or Down notifications to one notification host receiver using the Blue VRF and defines two SNMP users, Admin and NMS:

    configure terminal snmp-server contact Admin@company.com snmp-server user Admin auth sha abcd1234 priv abcdefgh snmp-server user NMS auth sha abcd1234 priv abcdefgh engineID 00:00:00:63:00:01:00:22:32:15:10:03 snmp-server host 192.0.2.1 informs version 3 auth NMS snmp-server host 192.0.2.1 use-vrf Blue snmp-server enable traps link cisco 

    This example shows how to configure SNMP to send traps using an inband port configured at the host level:

    switch# configure terminal Enter configuration commands, one per line. End with CNTL/Z. switch(config)# snmp-server host 171.71.48.164 version 2c public switch(config)# snmp-server host 171.71.48.164 source-interface ethernet 1/2 switch(config)# show snmp host ------------------------------------------------------------------- Host Port Version Level Type SecName ------------------------------------------------------------------- 171.71.48.164 162 v2c noauth trap public Source interface: Ethernet 1/2 ------------------------------------------------------------------- switch(config)# snmp-server host 171.71.48.164 use-vrf default switch(config)# show snmp host ------------------------------------------------------------------- Host Port Version Level Type SecName ------------------------------------------------------------------- 171.71.48.164 162 v2c noauth trap public Use VRF: default Source interface: Ethernet 1/2 ------------------------------------------------------------------- 

    This example shows how to configure SNMP to send traps using a globally configured inband port:

    switch# configure terminal Enter configuration commands, one per line. End with CNTL/Z. switch(config)# snmp-server source-interface traps ethernet 1/2 switch(config)# show snmp source-interface ------------------------------------------------------------------- Notification source-interface ------------------------------------------------------------------- trap Ethernet1/2 inform - ------------------------------------------------------------------- switch(config)# snmp-server host 171.71.48.164 use_vrf default switch(config)# show snmp host ------------------------------------------------------------------- Host Port Version Level Type SecName ------------------------------------------------------------------- 171.71.48.164 162 v2c noauth trap public Use VRF: default Source interface: Ethernet 1/2 ------------------------------------------------------------------- 

    This example shows how to map VRF red to the SNMPv2c public community string:

    switch# configure terminal Enter configuration commands, one per line. End with CNTL/Z. switch(config)# vrf context red switch(config-vrf)# exit switch(config)# snmp-server context public1 vrf red switch(config)# snmp-server mib community-map public context public1 

    This example shows how to map OSPF instance Enterprise to the same SNMPv2c public community string:

    switch# configure terminal Enter configuration commands, one per line. End with CNTL/Z. switch(config)# feature ospf switch(config)# router ospf Enterprise switch(config-router)# exit switch(config)# snmp-server context public1 instance Enterprise switch(config)# snmp-server mib community-map public context public1 

    Additional References

    Related Documents

    Related Topic	Document Title
    IP ACLs and AAA	Cisco Nexus 9000 Series NX-OS Security Configuration Guide
    MIBs	Cisco Nexus 7000 Series and 9000 Series NX-OS MIB Quick Reference

    RFCs

    RFC	Title
    RFC 3414	User-based Security Model (USM) for Version 3 of the Simple Network Management Protocol (SNMPv3)
    RFC 3415	View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)