Cisco MDS 9000 Family NX-OS System Management Configuration Guide
Configuring SNMP
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Configuring SNMP

Table Of Contents

Configuring SNMP

About SNMP Security

SNMP Version 1 and Version 2c

SNMP Version 3

Assigning SNMP Switch Contact and Location Information

SNMPv3 CLI User Management and AAA Integration

CLI and SNMP User Synchronization

Restricting Switch Access

Group-Based SNMP Access

Creating and Modifying Users

About AES Encryption-Based Privacy

Configuring SNMP Users from the CLI

Enforcing SNMPv3 Message Encryption

Assigning SNMPv3 Users to Multiple Roles

Adding or Deleting Communities

SNMP Trap and Inform Notifications

Configuring SNMPv2c Notifications

Configuring SNMPv3 Notifications

Enabling SNMP Notifications

Configuring the Notification Target User

Configuring LinkUp/LinkDown Notifications for Switches

Configuring Up/Down SNMP Link-State Traps for Interfaces

Scope of Link Up/Down Trap Settings

Displaying SNMP Security Information

Default Settings


Configuring SNMP


The CLI and SNMP use common roles in all switches in the Cisco MDS 9000 Family. You can use SNMP to modify a role that was created using the CLI and vice versa.

Users, passwords, and roles for all CLI and SNMP users are the same. A user configured through the CLI can access the switch using SNMP (for example, the Fabric Manager or the Device Manager) and vice versa.

This chapter includes the following sections:

About SNMP Security

SNMPv3 CLI User Management and AAA Integration

Creating and Modifying Users

SNMP Trap and Inform Notifications

Default Settings

About SNMP Security

SNMP is an application layer protocol that facilitates the exchange of management information between network devices. In all Cisco MDS 9000 Family switches, three SNMP versions are available: SNMPv1, SNMPv2c, and SNMPv3 (see Figure 9-1).

Figure 9-1 SNMP Security

This section includes the following topics:

SNMP Version 1 and Version 2c

SNMP Version 3

Assigning SNMP Switch Contact and Location Information

SNMP Version 1 and Version 2c

SNMP Version 1 (SNMPv1) and SNMP Version 2c (SNMPv2c) use a community string match for user authentication. Community strings provided a weak form of access control in earlier versions of SNMP. SNMPv3 provides much improved access control using strong authentication and should be preferred over SNMPv1 and SNMPv2c wherever it is supported.

SNMP Version 3

SNMP Version 3 (SNMPv3) is an interoperable standards-based protocol for network management. SNMPv3 provides secure access to devices by a combination of authenticating and encrypting frames over the network. The security features provided in SNMPv3 are:

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.

Assigning SNMP Switch Contact and Location Information

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

To configure contact and location information, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

Enters configuration mode.

Step 2 

switch(config)# snmp-server contact NewUser

Assigns the contact name for the switch.

switch(config)# no snmp-server contact NewUser

Deletes the contact name for the switch.

Step 3 

switch(config)# snmp-server location SanJose

Assigns the switch location.

switch(config)# no snmp-server location SanJose

Deletes the switch location.

SNMPv3 CLI User Management and AAA Integration

The Cisco NX-OS software implements RFC 3414 and RFC 3415, including user-based security model (USM) and role-based access control. While SNMP and the CLI have common role management and share the same credentials and access privileges, the local user database was not synchronized in earlier releases.

SNMPv3 user management can be centralized at the AAA server level. This centralized user management allows the SNMP agent running on the Cisco MDS switch to leverage the user authentication service of the AAA server. Once user authentication is verified, the SNMP PDUs are processed further. The AAA server also is used to store user group names. SNMP uses the group names to apply the access/role policy that is locally available in the switch.

This section includes the following topics:

CLI and SNMP User Synchronization

Restricting Switch Access

Group-Based SNMP Access

CLI and SNMP User Synchronization

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

To create an SNMP or CLI user, use either the username or snmp-server user commands.

The auth passphrase specified in the snmp-server user command is synchronized as the password for the CLI user.

The password specified in the username command is synchronized as the auth and priv passphrases for the SNMP user.

Users are synchronized as follows:

Deleting a user using either command results in the user being deleted for both SNMP and the CLI.

User-role mapping changes are synchronized in SNMP and the CLI.


Note When the passphrase/password is specified in localized key/encrypted format, the password is not synchronized.


Existing SNMP users continue to retain the auth and priv passphrases without any changes.

If the management station creates an SNMP user in the usmUserTable, the corresponding CLI user is created without any password (login is disabled) and will have the network-operator role.

Restricting Switch Access

You can restrict access to a Cisco MDS 9000 Family switch using IP Access Control Lists (IP-ACLs).

Group-Based SNMP Access


Note Because group is a standard SNMP term used industry-wide, we refer to role(s) as group(s) 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 three accesses: read access, write access, and notification access. Each access can be enabled or disabled within each group.

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

Creating and Modifying Users

You can create users or modify existing users using or the CLI.

SNMP—Create a user as a clone of an existing user in the usmUserTable on the switch. Once you have created the user, change the cloned secret key before activating the user. Refer to RFC 2574.

CLI—Create a user or modify an existing user using the snmp-server user command.

A network-operator and network-admin roles are available in a Cisco MDS 9000 Family switch. There is also a default-role if you want to use the GUI (Fabric Manager and Device Manager). You can also use any role that is configured in the Common Roles database.


Tip All updates to the CLI security database and the SNMP user database are synchronized. You can use the SNMP password to log into either Fabric Manager or Device Manager. However, after you use the CLI password to log into Fabric Manager or Device Manager, you must use the CLI password for all future logins. If a user exists in both the SNMP database and the CLI database before upgrading to Cisco MDS SAN-OS Release 2.0(1b), then the set of roles assigned to the user becomes the union of both sets of roles after the upgrade.


This section includes the following topics:

About AES Encryption-Based Privacy

Configuring SNMP Users from the CLI

Enforcing SNMPv3 Message Encryption

Assigning SNMPv3 Users to Multiple Roles

Adding or Deleting Communities

About AES Encryption-Based Privacy

The Advanced Encryption Standard (AES) is the symmetric cipher algorithm. The Cisco NX-OS software uses AES as one of the privacy protocols for SNMP 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 along with the aes-128 token indicates 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 characters. If you use the localized key, you can specify a maximum of 130 characters.


Note For an SNMPv3 operation using the external AAA server, user configurations in the external AAA server require AES to be the privacy protocol to use SNMP PDU encryption.


Configuring SNMP Users from the CLI

The passphrase specified in the snmp-server user command and the username command are synchronized.

To create or modify SNMP users from the CLI, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server user joe network-admin auth sha abcd1234

Creates or modifies the settings for a user (joe) in the network-admin role using the HMAC-SHA-96 authentication password (abcd1234).

switch(config)# snmp-server user sam network-admin auth md5 abcdefgh

Creates or modifies the settings for a user (sam) in the network-admin role using the HMAC-MD5-96 authentication password (abcdefgh).

switch(config)# snmp-server user Bill network-admin auth sha abcd1234 priv abcdefgh

Creates or modifies the settings for a user (Bill) in the network-admin role using the HMAC-SHA-96 authentication level and privacy encryption parameters.

switch(config)# no snmp-server user usernameA

Deletes the user (usernameA) and all associated parameters.

switch(config)# no snmp-server usam role vsan-admin

Deletes the specified user (usam) from the vsan-admin role.

 

switch(config)# snmp-server user user1 network-admin auth md5 0xab0211gh priv 0x45abf342 localizedkey

Specifies the password to be in localized key format (RFC 2574). The localized key is provided in hexadecimal format (for example, 0xacbdef).

 

switch(config)# snmp-server user user2 auth md5 asdgfsadf priv aes-128 asgfsgkhkj

Configures the user2 with the MD5 authentication protocol and AES-128 privacy protocol.

Step 3 

switch(config)# snmp-server user joe sangroup

Adds the specified user (joe) to the sangroup role.

switch(config)# snmp-server user joe techdocs

Adds the specified user (joe) to the techdocs role.

To create or modify passwords for SNMP users from the CLI, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server user user1 role1 auth md5 0xab0211gh priv 0x45abf342 localizedkey

Specifies the password to be in localized key format using the DES option for security encryption.

switch(config)# snmp-server user user1 role2 auth sha 0xab0211gh priv aes-128 0x45abf342 localizedkey

Specifies the password to be in localized key format using the 128-bit AES option for security encryption


Caution Avoid using the localizedkey option when configuring an SNMP user from the CLI. The localized keys are not portable across devices as they contain device engine ID information. If a configuration file is copied to the device, the passwords may not be set correctly if the configuration file was generated at a different device. Explicitly configure the desired passwords after copying the configuration into the device. Passwords specified with the localizedkey option are limited to 130 characters.


Note The snmp-server user command takes the engineID as an additional parameter. The engineID creates the notification target user (see the "Configuring the Notification Target User" section). If the engineID is not specified, the local user is created.


Enforcing SNMPv3 Message Encryption

By default the SNMP agent allows the securityLevel parameters of authNoPriv and authPriv for the SNMPv3 messages that use user-configured SNMPv3 message encryption with auth and priv keys.

To enforce the message encryption for a user, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server user testUser enforcePriv

Enforces the message encryption for SNMPv3 messages using this user.

Note You can only use this command for previously existing users configured with both auth and priv keys. When the user is configured to enforce privacy, for any SNMPv3 PDU request using securityLevel parameter of either noAuthNoPriv or authNoPriv, the SNMP agent responds with authorizationError.

switch(config)# no snmp-server user testUser enforcePriv

Disables SNMPv3 message encryption enforcement.

Alternatively, you can enforce the SNMPv3 message encryption globally on all the users using the following commands:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server globalEnforcePriv

Enforces the SNMPv3 message encryption for all the users on the switch.

switch(config)# no snmp-server globalEnforcePriv

Disables global SNMPv3 message encryption enforcement.

Assigning SNMPv3 Users to Multiple Roles

The SNMP server user configuration is enhanced to accommodate multiple roles (groups) for SNMPv3 users. After the initial SNMPv3 user creation, you can map additional roles for the user.


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


To configure multiple roles for SNMPv3 users from the CLI, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server user NewUser role1

Creates or modifies the settings for an SNMPv3 user (NewUser) for the role1 role.

switch(config)# snmp-server user NewUser role2

Creates or modifies the settings for an SNMPv3 user (NewUser) for the role2 role.

switch(config)# no snmp-server user User5 role2

Removes role2 for the specified user (User5).

Adding or Deleting Communities

You can configure read-only or read-write access for SNMPv1 and SNMPv2 users. Refer to RFC 2576.

To create an SNMPv1 or SNMPv2c community, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

Enters configuration mode.

Step 2 

switch(config)# snmp-server community snmp_Community ro

Adds read-only access for the specified SNMP community.

switch(config)# snmp-server community snmp_Community rw

Adds read-write access for the specified SNMP community.

switch(config)# no snmp-server community snmp_Community

Deletes access for the specified SNMP community (default).

SNMP Trap and Inform Notifications

You can configure the Cisco MDS switch to send notifications to SNMP managers when particular events occur.


Note You must enable the RMON traps in the SNMP configuration. For more information refer to Configuring RMON



Note Use the SNMP-TARGET-MIB to obtain more information on the destinations to which notifications are to be sent either as traps or as informs. Refer to the Cisco MDS 9000 Family MIB Quick Reference.


This section includes the following topics:

Configuring SNMPv2c Notifications

Configuring SNMPv3 Notifications

Enabling SNMP Notifications

Configuring the Notification Target User

Configuring LinkUp/LinkDown Notifications for Switches

Configuring Up/Down SNMP Link-State Traps for Interfaces

Displaying SNMP Security Information


Tip The SNMPv1 option is not available with the snmp-server host ip-address informs command.


Configuring SNMPv2c Notifications

To configure SNMPv2c notifications using IPv4, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server host 171.71.187.101 traps version 2c private udp-port 1163

Configures the specified host to receive SNMPv2c traps using SNMPv2c community string (private).

switch(config)# no snmp-server host 171.71.187.101 traps version 2c private udp-port 2162

Prevents the specified host from receiving SNMPv2c traps on the configured UDP port using SNMPv2c community string (private).

Step 3 

switch(config)# snmp-server host 171.71.187.101 informs version 2c private udp-port 1163

Configures the specified host to receive SNMPv2c informs using SNMPv2c community string (private).

switch(config)# no snmp-server host 171.71.187.101 informs version 2c private udp-port 2162

Prevents the specified host from receiving SNMPv2c informs on the configured UDP port using SNMPv2c community string (private).

To configure SNMPv2c notifications using IPv6, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server host 2001:0DB8:800:200C::417A traps version 2c private udp-port 1163

Configures the specified host to receive SNMPv2c traps using SNMPv2c community string (private).

switch(config)# no snmp-server host 2001:0DB8:800:200C::417A traps version 2c private udp-port 2162

Prevents the specified host from receiving SNMPv2c traps on the configured UDP port using SNMPv2c community string (private).

Step 3 

switch(config)# snmp-server host 2001:0DB8:800:200C::417A informs version 2c private udp-port 1163

Configures the specified host to receive SNMPv2c informs using SNMPv2c community string (private).

switch(config)# no snmp-server host 2001:0DB8:800:200C::417A informs version 2c private udp-port 2162

Prevents the specified host from receiving SNMPv2c informs on the configured UDP port using SNMPv2c community string (private).


Note Switches can forward events (SNMP traps and informs) up to 10 destinations.


Configuring SNMPv3 Notifications

To configure SNMPv3 notifications using IPv4, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server host 16.20.11.14 traps version 3 noauth testuser udp-port 1163

Configures the specified host to receive SNMPv3 traps using SNMPv3 user (testuser) and securityLevel of noAuthNoPriv.

switch(config)# snmp-server host 16.20.11.14 informs version 3 auth testuser udp-port 1163

Configures the specified host to receive SNMPv3 informs using SNMPv3 user (testuser) and securityLevel of AuthNoPriv.

switch(config)# snmp-server host 16.20.11.14 informs version 3 priv testuser udp-port 1163

Configures the specified host to receive SNMPv3 informs using SNMPv3 user (testuser) and securityLevel of AuthPriv.

switch(config)# no snmp-server host 172.18.2.247 informs version 3 testuser noauth udp-port 2162

Prevents the specified host from receiving SNMPv3 informs.

To configure SNMPv3 notifications using IPv6, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server host 2001:0DB8:800:200C::417A traps version 3 noauth testuser udp-port 1163

Configures the specified host to receive SNMPv3 traps using SNMPv3 user (testuser) and securityLevel of noAuthNoPriv.

switch(config)# snmp-server host 2001:0DB8:800:200C::417A informs version 3 auth testuser udp-port 1163

Configures the specified host to receive SNMPv3 informs using SNMPv3 user (testuser) and securityLevel of AuthNoPriv.

switch(config)# snmp-server host 2001:0DB8:800:200C::417A informs version 3 priv testuser udp-port 1163

Configures the specified host to receive SNMPv3 informs using SNMPv3 user (testuser) and securityLevel of AuthPriv.

switch(config)# no snmp-server host 2001:0DB8:800:200C::417A informs version 3 testuser noauth udp-port 2162

Prevents the specified host from receiving SNMPv3 informs.


Note In the case of SNMPv3 notifications, the SNMP manager is expected to know the user credentials (authKey/PrivKey) based on the switch's engineID to authenticate and decrypt the SNMP messages.


Enabling SNMP Notifications

Notifications (traps and informs) are system alerts that the switch generates when certain events occur. You can enable or disable notifications. By default, no notification is defined or issued. If a notification name is not specified, all notifications are disabled or enabled.

With the SNMP central infra feature, you can add the traps that need to be enabled or disabled. The MIB CISCO-NOTIFICATION-CONTROL-MIB is supported to enable the use of a MIB browser to control notification generation.

You can enable or disable the supported traps at the following levels:

Switch level—You can use snmp-server enable traps command to enable all the traps in the supported MIBs at the switch level.

Feature level—You can use snmp-server enable traps command with the feature name to enable traps at the feature level.

switch =>snmp-server enable traps callhome ?
event-notify    Callhome External Event Notification
smtp-send-fail  SMTP Message Send Fail notification
 
   

Individual traps - You can use snmp-server enable traps command with the feature name to enable traps at the individual level.

switch =>snmp-server enable traps callhome event-notify ?

Table 9-1 lists the CLI commands that enable the notifications for Cisco NX-OS MIBs.


Note The snmp-server enable traps CLI command enables both traps and informs, depending on how you configured SNMP. See the notifications displayed with the snmp-server host CLI command.


Table 9-1 Enabling SNMP Notifications 

MIB
Related Commands

All notifications

snmp-server enable traps

CISCO-AAA-SERVER-MIB

snmp-server enable traps aaa

ENITY-MIB, CISCO-ENTITY-FRU-CONTROL-MIB, CISCO-ENTITY-SENSOR-MIB

snmp-server enable traps entity
snmp-server enable traps entity fru

CISCO-FCC-MIB

snmp-server enable traps fcc

CISCO-DM-MIB

snmp-server enable traps fcdomain

CISCO-NS-MIB

snmp-server enable traps fcns

CISCO-FCS-MIB

snmp-server enable traps fcs discovery-complete
snmp-server enable traps fcs request-reject

CISCO-FDMI-MIB

snmp-server enable traps fdmi

CISCO-FSPF-MIB

snmp-server enable traps fspf

CISCO-LICENSE-MGR-MIB

snmp-server enable traps license

IF-MIB

snmp-server enable traps link

CISCO-PSM-MIB

snmp-server enable traps port-security

CISCO-RSCN-MIB

snmp-server enable traps rscn
snmp-server enable traps rscn els
snmp-server enable traps rscn ils

SNMPv2-MIB

snmp-server enable traps snmp
snmp-server enable traps snmp authentication

VRRP-MIB, CISCO-IETF-VRRP-MIB

snmp-server enable traps vrrp

CISCO-ZS-MIB

snmp-server enable traps zone
snmp-server enable traps zone default-zone-behavior-change
snmp-server enable traps zone merge-failure
snmp-server enable traps zone merge-success
snmp-server enable traps zone request-reject
snmp-server enable traps zone unsupp-mem


The following notifications are enabled by default:

entity fru

license

link ietf-extended

All other notifications are disabled by default.

To enable individual notifications, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server enable traps fcdomain

Enables the specified SNMP (fcdomain) notification.

switch(config)# no snmp-server enable traps

Disables the specified SNMP notification. If a notification name is not specified, all notifications are disabled.

You can use the show snmp trap command to display all the notifications and their status.

switch# show snmp trap
Trap type 																	Enabled
---------                           																	-------
entity               : entity_mib_change                            Yes
entity               : entity_module_status_change                  Yes
entity               : entity_power_status_change                   Yes
entity               : entity_module_inserted                       Yes
entity               : entity_module_removed                        Yes
entity               : entity_unrecognised_module                   Yes
entity               : entity_fan_status_change                     Yes
entity               : entity_power_out_change                      Yes
link                 : linkDown                                     Yes
link                 : linkUp                                       Yes
link                 : extended-linkDown                            Yes
link                 : extended-linkUp                              Yes
link                 : cieLinkDown                                  Yes
link                 : cieLinkUp                                    Yes
link                 : connUnitPortStatusChange                     Yes
link                 : fcTrunkIfUpNotify                            Yes
link                 : fcTrunkIfDownNotify                          Yes
link                 : delayed-link-state-change                    Yes
link                 : fcot-inserted                                Yes
link                 : fcot-removed                                 Yes
callhome             : event-notify                                 Yes
cfs                  : merge-failure                                Yes
fcdomain             : dmNewPrincipalSwitchNotify                   Yes
fcdomain             : dmDomainIdNotAssignedNotify                  Yes
fcdomain             : dmFabricChangeNotify                         Yes
ivr                  : activation-complete                          Yes
ivr                  : deactivation-complete                        Yes
ivr                  : domain-conflict                              Yes
fcsp                 : fcsp                                         Yes
rf                   : redundancy_framework                         Yes
aaa                  : server-state-change                          Yes
license              : notify-license-expiry                        Yes
license              : notify-no-license-for-feature                Yes
license              : notify-licensefile-missing                   Yes
license              : notify-license-expiry-warning                Yes
scsi                 : scsi-disc-complete                           Yes
fcns                 : reject-reg-req                               Yes
fcns                 : local-entry-change                           Yes
fcns                 : db-full                                      Yes
fcns                 : remote-entry-change                          Yes
rscn                 : rscnElsRejectReqNotify                       Yes
rscn                 : rscnIlsRejectReqNotify                       Yes
rscn                 : rscnElsRxRejectReqNotify                     Yes
rscn                 : rscnIlsRxRejectReqNotify                     Yes
fcs                  : request-reject                               Yes
fcs                  : discovery-complete                           Yes
fctrace              : route                                        Yes
zone                 : request-reject1                              Yes
zone                 : merge-success                                Yes
zone                 : merge-failure                                Yes
zone                 : default-zone-behavior-change                 Yes
zone                 : unsupp-mem                                   Yes
port-security        : fport-violation                              Yes
port-security        : eport-violation                              Yes
port-security        : fabric-binding-violation                     Yes
ipsec                : CryptoMap-Added                              Yes
ipsec                : CryptoMap-Deleted                            Yes
ipsec                : CryptoMap-Attached                           Yes
ipsec                : CryptoMap-Detached                           Yes
vni                  : virtual-interface-created                    Yes
vni                  : virtual-interface-removed                    Yes
vsan                 : vsanStatusChange                             Yes
vsan                 : vsanPortMembershipChange                     Yes
fspf                 : fspfNbrStateChangeNotify                     Yes
upgrade              : UpgradeOpNotifyOnCompletion                  Yes
upgrade              : UpgradeJobStatusNotify                       Yes
feature-control      : FeatureOpStatusChange                        Yes
callhome             : smtp-send-fail                               Yes
cfs                  : state-change-notif                           Yes
snmp                 : authentication                               Yes
 
   

Configuring the Notification Target User

You must configure a notification target user on the switch for sending SNMPv3 inform notifications to the SNMP manager.

To configure the notification target user, use the following command:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# snmp-server user testusr auth md5 xyub20gh priv xyub20gh engineID 00:00:00:63:00:01:00:a1:ac:15:10:03

Configures the notification target user with the specified credentials for the SNMP manager with the specified engine ID.

switch(config)# no snmp-server user testusr auth md5 xyub20gh priv xyub20gh engineID 00:00:00:63:00:01:00:a1:ac:15:10:03

Removes the notification target user.

The credentials of the notification target user are used for encrypting the SNMPv3 inform notification messages to the configured SNMPmanager (as in the snmp-server host command).


Note For authenticating and decrypting the received INFORM PDU, the SNMP manager should have the same user credentials in its local configuration data store of users.


Configuring LinkUp/LinkDown Notifications for Switches

You can configure which linkUp/linkDown notifications to enable on switches. You can enable the following types of linkUp/linkDown notifications:

Cisco—Only notifications (cieLinkUp, cieLinkDown) defined in CISCO-IF-EXTENSION-MIB.my are sent for an interface, if ifLinkUpDownTrapEnable (defined in IF-MIB) is enabled for that interface.

IETF—Only notifications (linkUp, linkDown) defined in IF-MIB are sent for an interface, if ifLinkUpDownTrapEnable (defined in IF-MIB) is enabled for that interface. Only the varbinds defined in the notification definition are sent with the notifications.

IEFT extended—Only notifications (linkUp, linkDown) defined in IF-MIB are sent for an interface, if ifLinkUpDownTrapEnable (defined in IF-MIB) is enabled for that interface. In addition to the varbinds defined in the notification definition, varbinds defined in the IF-MIB specific to the Cisco Systems implementation are sent. This is the default setting.

IEFT Cisco—Only notifications (linkUp, linkDown) defined in IF-MIB and notifications (cieLinkUp, cieLinkDown) defined in CISCO-IF-EXTENSION-MIB.my are sent for an interface, if ifLinkUpDownTrapEnable (defined in IF-MIB) is enabled for that interface. Only the varbinds defined in the notification definition are sent with the linkUp and linkDown notifications.

IEFT extended Cisco—Only notifications (linkUp, linkDown) defined in IF-MIB and notifications (cieLinkUp, cieLinkDown) defined in CISCO-IF-EXTENSION-MIB.my are sent for an interface, if ifLinkUpDownTrapEnable (defined in IF-MIB) is enabled for that interface. In addition to the varbinds defined in linkUp and linkDown notification definition, varbinds defined in the IF-MIB specific to the Cisco Systems implementation are sent with the linkUp and linkDown notifications.


Note For more information on the varbinds defined in the IF-MIB specific to the Cisco Systems implementation, refer to the Cisco MDS 9000 Family MIB Quick Reference.


To configure the linkUp/linkDown notification for a switch using NX-OS Release 4.1(x) and earlier, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 1 

switch(config)# snmp-server enable traps link

Enables (default) only IETF extended linkUp/linkDown notifications.

switch(config)# snmp-server enable traps link cisco

Enables only Cisco Systems defined cieLinkUp/cieLinkDown notifications.

switch(config)# snmp-server enable traps link ietf

Enables only IETF linkUp/linkDown notifications.

switch(config)# snmp-server enable traps link ietf-extended

Enables (default) only IETF extended linkUp/linkDown notifications with extra varbinds.

switch(config)# snmp-server enable traps link ietf cisco

Enables IETF (linkUp/linkDown) and Cisco Systems defined (cieLinkUp/cieLinkDown) notifications.

switch(config)# snmp-server enable traps link ietf-extended cisco

Enables IEFT (linkUp/linkDown) notifications with extra varbinds and Cisco Systems defined (cieLinkUp/cieLinkDown) notifications.

switch(config)# no snmp-server enable traps link

Reverts to the default setting (IETF extended).


Note If both IETF and IETF extended are enabled, the show snmp traps command displays both as enabled. However, as a trap, you will receive only one trap with IETF extended payload.


To configure the linkUp/linkDown notification for a switch using NX-OS Release 4.2(1) and later, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 1 

switch(config)# snmp-server enable traps link

Enables (default) only IETF extended linkUp/linkDown notifications.

switch(config)# snmp-server enable traps link cieLinkDown

Enables Cisco extended link state down notification.

switch(config)# snmp-server enable traps link cieLinkUp

Enables Cisco extended link state up notification.

switch(config)# snmp-server enable traps link connUnitPortStatusChange

Enables FCMGMT The overall status of the connectivity unit Notification.

switch(config)# snmp-server enable traps link delayed-link-state-change

Enables Delayed link state change.

switch(config)# snmp-server enable traps link extended-linkDown

Enables IETF extended link state down notification.

switch(config)# snmp-server enable traps link extended-linkUp

Enables IETF extended link state down notification.

switch(config)# snmp-server enable traps link fcTrunkIfDownNotify

Enables FCFE Link state down notification.

switch(config)# snmp-server enable traps link fcTrunkIfUpNotify

Enables FCFE Link state up notification.

switch(config)# snmp-server enable traps link fcot-inserted

Enables FCOT info trap.

switch(config)# snmp-server enable traps link fcot-removed

Enables FCOT info trap.

switch(config)# snmp-server enable traps link linkDown

Enables IETF Link state down notification.

switch(config)# snmp-server enable traps link linkUp

Enables IETF Link state up notification.

switch(config)# no snmp-server enable traps link

Reverts to the default setting (IETF extended).

Configuring Up/Down SNMP Link-State Traps for Interfaces

By default, SNMP link-state traps are enabled for all interfaces. Whenever a link toggles its state from Up to Down or vice versa, an SNMP trap is generated.

In some instances, you may find that you have numerous switches with hundreds of interfaces, many of which do not require monitoring of the link state. In such cases, you may elect to disable link-state traps.To disable SNMP link-state traps for specific interfaces, follow these steps:

 
Command
Purpose

Step 1 

switch# config t

switch(config)#

Enters configuration mode.

Step 2 

switch(config)# interface bay 6

Specifies the interface on which to disable SNMP link-state traps.

switch(config-if)# no link-state-trap

Disables SNMP link-state traps for the interface.

switch(config-if)# link-state-trap

Enables SNMP link-state traps for the interface.

Whenever you disable an SNMP link-state trap for an interface, the command is also added to the running configuration of the system. To view the running configuration, enter the show running-config command for the interface.

switch# show running-config
version 3.1(2)
....
interface bay5
interface bay6
  no link-state-trap <-----command is added to the running configuration for the interface
interface bay7...

To view the SNMP link-state trap configuration for a particular interface, enter the show interface command.

switch# show interface bay 6
bay6 is down (Administratively down)
    Hardware is Fibre Channel 
    Port WWN is 20:0b:00:05:30:01:70:2c
    Admin port mode is auto, trunk mode is on
    snmp link-state traps are disabled
 
   
    Port vsan is 1
    Receive data field Size is 2112
    Beacon is turned off
    5 minutes input rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
    5 minutes output rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
      0 frames input, 0 bytes
        0 discards, 0 errors
        0 CRC,  0 unknown class
        0 too long, 0 too short
      0 frames output, 0 bytes
        0 discards, 0 errors
      0 input OLS, 0 LRR, 0 NOS, 0 loop inits
      0 output OLS, 0 LRR, 0 NOS, 0 loop inits
 
   

Scope of Link Up/Down Trap Settings

The link Up/Down trap settings for the interfaces generate traps based on the following scope:

Switch-level Trap Setting
Interface-level Trap Setting
Trap Generated for Interface Links?

Enabled (defualt)

Enabled (default)

Yes

Enabled

Disabled

No

Disabled

Enabled

No

Disabled

Disabled

No


Displaying SNMP Security Information

Use the show snmp commands to display configured SNMP information (see Example 9-1 and 9-6).

Example 9-1 Displays SNMP User Details

switch# show snmp user
______________________________________________________________
                  SNMP USERS
______________________________________________________________
 
   
User                          Auth  Priv(enforce) Groups
____                          ____  _____________ ______
admin                         md5   des(no)       network-admin
 
   
testusr                       md5   aes-128(no)   role111
                                                  role222
______________________________________________________________
 NOTIFICATION TARGET USERS (configured  for sending V3 Inform)
______________________________________________________________
User                          Auth  Priv
____                          ____  ____
testtargetusr                 md5   des
(EngineID 0:0:0:63:0:1:0:0:0:15:10:3)
 
   

Example 9-2 Displays SNMP Community Information

switch# show snmp community 
Community                      Access
---------                      ------
private                         rw
public                          ro
v93RACqPNH                      ro

Example 9-3 Displays SNMP Host Information

switch# show snmp host
Host                            Port Version  Level  Type   SecName
____                            ____ _______  ______ ____  ______
171.16.126.34                   2162 v2c      noauth trap   public
171.16.75.106                   2162 v2c      noauth trap   public
...
171.31.58.97                    2162 v2c      auth   trap   public
...

The show snmp command displays counter information for SNMP contact, location, and packet settings. This command provides information that is used entirely by the Cisco MDS 9000 Family Fabric Manager (refer to the Cisco Fabric Manager System Management Configuration Guide). See Example 9-4.

Example 9-4 Displays SNMP Information

switch# show snmp
sys contact:
sys location:
1631 SNMP packets input
        0 Bad SNMP versions
        0 Unknown community name
        0 Illegal operation for community name supplied
        0 Encoding errors
        64294 Number of requested variables
        1 Number of altered variables
        1628 Get-request PDUs
        0 Get-next PDUs
        1 Set-request PDUs
152725 SNMP packets output
        0 Too big errors
        1 No such name errors
        0 Bad values errors
        0 General errors
Community                      Group / Access
---------                      ------
public                          rw
 
   
______________________________________________________________
                  SNMP USERS
______________________________________________________________
 
   
User                          Auth  Priv(enforce) Groups
____                          ____  _____________ ______
admin                         md5   des(no)       network-admin
 
   
testusr                       md5   aes-128(no)   role111
                                                  role222
 
   
______________________________________________________________
 NOTIFICATION TARGET USERS (configured  for sending V3 Inform)
______________________________________________________________
 
   
User                          Auth  Priv
____                          ____  ____
testtargetusr                 md5   des
(EngineID 0:0:0:63:0:1:0:0:0:15:10:3)
 
   

Example 9-5 Displays SNMP Engine IDs

switch# show snmp engineID
Local SNMP engineID: [Hex] 8000000903000DEC2CF180
                     [Dec] 128:000:000:009:003:000:013:236:044:241:128
 
   

Example 9-6 Displays Information on SNMP Security Groups

switch# show snmp group
groupname: network-admin
security model: any
security level: noAuthNoPriv
readview: network-admin-rd
writeview: network-admin-wr
notifyview: network-admin-rd
storage-type: permanent
row status: active
 
   
groupname: network-admin
security model: any
security level: authNoPriv
readview: network-admin-rd
writeview: network-admin-wr
notifyview: network-admin-rd
storage-type: permanent
row status: active
 
   
groupname: network-operator
security model: any
security level: noAuthNoPriv
readview: network-operator-rd
writeview: network-operator-wr
notifyview: network-operator-rd
storage-type: permanent
row status: active
 
   
groupname: network-operator
security model: any
security level: authNoPriv
readview: network-operator-rd
writeview: network-operator-wr
notifyview: network-operator-rd
storage-type: permanent
row status: active
 
   

Default Settings

Table 9-2 lists the default settings for all SNMP features in any switch.

Table 9-2 Default SNMP Settings 

Parameters
Default

User account

No expiry (unless configured)

Password

None