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 33-1).
Figure 33-1 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.
|
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 SAN-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. 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.
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). SeeChapter 35, "Configuring IPv4 and IPv6 Access Control Lists,".
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 SNMP, 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 (see the "User Accounts" section on page 39-10).
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 SAN-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 (see the "SNMPv3 CLI User Management and AAA Integration" section).
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 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.
Table 33-1 lists the CLI commands that enable the notifications for Cisco MDS MIBs.
Note The snmp-server enable traps CLI command enables both traps and informs, depending on how you configured . See notifications with the snmp-server host CLI command.
Table 33-1 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.
fcs discovery-complete No
zone unsupported member No
zone default-zone-behavior-change No
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 SNMP manager (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, 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).
|
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
no link-state-trap <-----command is added to the running configuration for the interface
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
Receive data field Size is 2112
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 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 33-1 and 33-6).
Example 33-1 Displays SNMP User Details
______________________________________________________________
______________________________________________________________
User Auth Priv(enforce) Groups
____ ____ _____________ ______
admin md5 des(no) network-admin
testusr md5 aes-128(no) role111
______________________________________________________________
NOTIFICATION TARGET USERS (configured for sending V3 Inform)
______________________________________________________________
(EngineID 0:0:0:63:0:1:0:0:0:15:10:3)
Example 33-2 Displays SNMP Community Information
switch# show snmp community
Example 33-3 Displays SNMP Host Information
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 MDS 9000 Family Fabric Manager Configuration Guide). See Example 33-4.
Example 33-4 Displays SNMP Information
0 Illegal operation for community name supplied
64294 Number of requested variables
1 Number of altered variables
152725 SNMP packets output
______________________________________________________________
______________________________________________________________
User Auth Priv(enforce) Groups
____ ____ _____________ ______
admin md5 des(no) network-admin
testusr md5 aes-128(no) role111
______________________________________________________________
NOTIFICATION TARGET USERS (configured for sending V3 Inform)
______________________________________________________________
(EngineID 0:0:0:63:0:1:0:0:0:15:10:3)
Example 33-5 Displays SNMP Engine IDs
switch# show snmp engineID
Local SNMP engineID: 800000090300053000851E
Example 33-6 Displays Information on SNMP Security Groups
security level: noAuthNoPriv
readview: network-admin-rd
writeview: network-admin-wr
notifyview: network-admin-rd
security level: authNoPriv
readview: network-admin-rd
writeview: network-admin-wr
notifyview: network-admin-rd
groupname: network-operator
security level: noAuthNoPriv
readview: network-operator-rd
writeview: network-operator-wr
notifyview: network-operator-rd
groupname: network-operator
security level: authNoPriv
readview: network-operator-rd
writeview: network-operator-wr
notifyview: network-operator-rd
Default Settings
Table 33-2 lists the default settings for all SNMP features in any switch.
Table 33-2 Default SNMP Settings
Parameters
|
Default
|
User account
|
No expiry (unless configured).
|
Password
|
None.
|
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