Contents

1   About SNMP

The Simple Network Management Protocol (SNMP) allows you to monitor network devices from a central location. This section provides an overview of SNMP.

SNMP defines the standards used to monitor one or more network devices.

An SNMP management system contains the following parts:

• One or more SNMP agents
• SNMP Manager (entity containing command generator or notification receiver applications)
• Protocol to communicate information between the SNMP agent and manager entities.

  The following are examples of protocols SNMP uses to communicate between entities:

  • Trap notifications—for example, traps and events
  • Get requests
  • Set requests
  • Management Information Bases (MIBs)

1.1   MIBs

The Management Information Base (MIB) is a virtual database of defined objects used to manage network devices. MIB objects are organized hierarchically and each object has a unique object identifier (OID). You can read and write objects to obtain information about a network by using a network-management protocol, such as SNMP. For a list of SNMP standards, see the SNMP Management Framework and RFCs section. For information about SmartEdge OS standard MIB support, see Standard SNMP MIBs.

The SmartEdge™ router supports enterprise-specific MIBs and standard MIBs defined by Ericsson and standard MIBs defined by standards bodies, such as the Internet Engineering Task Force (IETF), International Telecommunications Union (ITU), and Institute of Electrical and Electronics Engineers, Inc. (IEEE). For information about the enterprise-specific MIBs (including the OIDs), see Enterprise MIBs.

OIDs are identifiable by numbers. These numbers represent the hierarchy of the object in the MIB. For example, all Ericsson proprietary MIBs start with the OID syntax 1.3.6.1.4.1.2352.2.xyz. This syntax indicates that .xyz is located in the MIB hierarchy in the following way (numbers in parentheses show their placement in the MIB hierarchy; however, in the system, MIB OIDs are displayed as numbers only):

The following example shows the hierarchy of the MIB.

iso(1).org(3).dod(6).internet(1).private(4).enterprises
(1).redBackNetworks(2352).rbnMgmt(2).xyz

You can also identify an object by its object name. For example, ifNumber in IF-MIB can be identified by its object name (iso.org.dod.internet.mgmt.enterprises.interfaces.ifNumber) or OID (1.3.6.1.2.1.2.1). This document identifies OIDs by object names and numerical format.

1.2   Capability Statements

For the enterprise MIBs, updates are documented in capability statements (CAP files), organized by software release (similar to a revision history). Standard MIBs do not contain capability statements.

1.3   Notifications

An SNMP agent sends notifications to a network manager when certain system events occur. A standard or proprietary MIB defines these notifications, also called traps or events. Notifications are defined in various standard and enterprise-specific MIB modules. For more information about notifications used in the SmartEdge router , see SNMP MIB Notifications.

Examples of notifications that can occur in the SmartEdge router include:

• A card restarts
• An XCRP is replaced
• The system reaches too high a temperature

See Configure SNMPv1 and SNMPv2 or Configure SNMPv3 for instructions on how to enable notifications on the SmartEdge router . Use the snmp-server host command to specify whether to send SNMP notifications as traps or informs (informational notifications).

1.4   SNMP Management Framework and RFCs

The following components and standards documents define the SNMP management framework:

• Overall architecture—Described in RFC 3411, An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks
• Mechanisms for describing and naming objects and events for the purpose of management:

  The first version, Structure of Management Information (SMIv1) as described in:

  • STD 16, RFC 1155, Structure and Identification of Management Information for TCP/IP-based Internets
  • STD 15, RFC 1157, A Simple Network Management Protocol (SNMP)
  • STD 16, RFC 1212, Concise MIB Definitions
  • RFC 1215, Convention for Defining Traps for Use with the SNMP
  
  

  The second version, SMIv2, as described in:

  • STD 58, RFC 2578, Structure of Management Information Version 2 (SMIv2)
  • STD 58, RFC 2579, Textual Conventions for SMIv2
  • STD 58, RFC 2580, Conformance Statements for SMIv2
  • RFC 3416, Version 2 of the Protocol Operations for the Simple Network Management Protocol (SNMP)
  • RFC 1901, Introduction to Community-based SNMPv2
  
  

  SNMP Version 3 (SNMPv3):

  • STD 62, RFC 3410, Introduction and Applicability Statements for Internet Standard Management Framework
  • RFC 3411, An Architecture for Describing SNMP Management Frameworks
  • RFC 3412 Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)
  • RFC 3413 SNMPv3 Applications
  • RFC 3414 User-based Security Model (USM) for version 33 of the Simple Network Management Protocol (SNMPv3)
  • RFC 3415 View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)
  • RFC 3416 Version 2 of the Protocol Operations for the Simple Network Management Protocol (SNMP)
  • RFC 3417 Transport Mappings for the Simple Network Management Protocol (SNMP)
  • RFC 3418 Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)
  • STD 62, RFC 3584, Coexistence between Version 1, Version 2, and Version 3 of the Internet-Standard Network Management Framework

The SmartEdge router supports the User-Based Security Model (USM) and the following applications specific to RFC 3413 and RFC 3414:

• Command Responder—The SmartEdge router accepts SNMP read-class and write-class requests, performs the appropriate protocol operation, and generates a response message.
• Notification Originator—The SmartEdge router monitors the system for particular events and conditions and generates notification-class messages based on these events or conditions.

Managed objects are accessed through a virtual information store, the Management Information Base (MIB). MIB objects are defined using the mechanisms set out in the Structure of Management Information (SMI); for more information, see the MIBs section.

Other supported RFCs are:

• RFC 1155 Structure and Identification of Management Information for TCP/IP-based Internets
• RFC 2790 Host Resources MIB
• RFC 4113 Management Information Base for the User Datagram Protocol (UDP)

1.5   SNMP Versions

The SmartEdge router supports SNMP Version 1 (SNMPv1), Version 2c (SNMPv2), and Version 3 (SNMPv3).

There are several differences between configuring SNMPv1 and SNMPv2, and configuring SNMPv3:

• With SNMPv1 and 2c, communities are created to control access to MIB information. You can configure these communities to meet management requirements. For instance, you can set up the automatic generation of community strings for all managed Ericsson contexts. This automatically creates a group with the same name as the community string.
• With SNMPv3, groups and users (instead of communities) are manually configured to control access to MIB information. Privacy and encryption options ensure a high level of configurable security.
• SNMPv3 uses engine IDs to provide additional security.

2   Configuring RMON

To configure RMON, perform the tasks in the following sections.

2.1   Configuring RMON Features

To configure RMON features, perform the tasks described in Table 1; enter all commands in global configuration mode.

Note:  

You must first enable the SNMP server before you can configure RMON features.

2.2   Displaying RMON Information

Table 2 lists the operations tasks for SNMP and Remote Monitoring (RMON). Enter the show commands in any mode; enter all other commands in exec mode.

3   Configuring SNMP

To configure SNMP, perform the tasks in the following sections.

3.1   Configuring SNMPv1 and SNMPv2

To configure SNMPv1 and SNMPv2 for SNMP target management stations, such as the NetOp Element Management System (EMS) server, perform the tasks described in Table 3; enter all commands in global configuration mode unless otherwise noted.

Table 4 lists the operations tasks for SNMP and Remote Monitoring (RMON). Enter the show commands in any mode; enter all other commands in exec mode.

3.2   Example: Using SNMPv2

In the following SNMPv2 example, the view Inet-View includes all objects in the Internet object identifier (OID) tree. The Admin community allows read access to the Inet-View view, and then the SmartEdge router is configured to send traps to a system, NM-Station1, with an IP address of 198.164.190.110:

[local]Redback(config)#snmp server
[local]Redback(config-snmp-server)#traps ifmib encaps
[local]Redback(config-snmp-server)#exit
[local]Redback(config)#snmp view Inet-View internet included 
[local]Redback(config)#snmp community Admin view Inet-View read-only
[local]Redback(config)#snmp target NM-Station1 198.164.190.110 
security-name Admin version 2c view Inet-View trap
[local]Redback(config)#end

3.3   Configuring SNMPv3

Follow these guidelines to maximize security and ensure proper configuration of SNMPv3 for SNMP target management stations such as the NetOp EMS server:

• Define unique engine IDs—Do not define the engine ID value in a configuration file that will be applied to multiple systems.
• Protect configuration files—If you create configuration files that contain security information, such as authorization passwords and keys, the files should be stored on a secured system.
• Do not use saved configurations on multiple systems—SNMP security data is system-dependent. You compromise security if the same SNMP security data is assigned to multiple systems.

To configure SNMPv3, perform the tasks described in Table 5; enter all commands in global configuration mode, unless otherwise noted.

(1)  Option 1 and Option 2 are mutually exclusive. The snmp target command is equivalent to the set of commands of Option 2, but only if, in step 3, the SNMP group was created without a notification view identified (the snmp group command with the notifynotify-view construct).

3.4   Example: Using SNMPv3

The following SNMPv3 example configures the Inet-View view to include all objects in the Internet MIB tree. It also configures an authenticated group, Group4, to allow read and notify access to the Inet-View view, and a user, Admin, who is part of Group4, with an encoded authorization password. It also configures the SmartEdge router to send inform notifications from the Inet-View view to a system, Nm-Station1 (IP address 10.3.4.5), excluding the rbnSRMIBNotifications trap:

[local]Redback(config)#snmp server
[local]Redback(config-snmp-server)#traps ifmib encaps
[local]Redback(config-snmp-server)#exit
[local]Redback(config)#snmp engine-id local AA:00:00:00:01
[local]Redback(config)#snmp view Inet-View internet included 
[local]Redback(config)#snmp group Group4 security-model usm auth read 
Inet-View notify Inet-View
[local]Redback(config)#snmp user Admin group Group4 security-model usm 
md5 key encoded base64 L1sR+UKZj4PqeRodf3zqTg==
[local]Redback(config)#snmp notify Notify-Inform Tag-Inform inform
[local]Redback(config)#snmp notify-filter Filter-incInet 1.3.*.4 included
[local]Redback(config)#snmp notify-filter Filter-NOrbnSRMIB 
rbnSRMIBNotifications excluded
[local]Redback(config)#snmp target-parameters Param2 security-name 
Admin version 3 security-level auth 
[local]Redback(config)#snmp notify-target Nm-Station1 10.3.4.5/24 tag Inet-Informs parameters Param2 filter Filter-NOrbnSRMIB

3.5   Displaying SNMP Statistics

Table 6 lists the operations tasks for SNMP and RMON. Enter the show commands in any mode; enter all other commands in exec mode.

3.6   Generating SNMP Debug Messages

Table 7 lists the operations tasks for SNMP and Remote Monitoring (RMON). Enter the show commands in any mode; enter all other commands in exec mode.

3.7   Example: Setting SNMP Command Privileges

The following example assigns the minimum privilege level to all commands that start with the snmp keyword to 12:

[local]Redback(config)#privilege config inherit level 12 snmp

4   Configuring MIB Information to Display OIDs in Human-Readable Form

Note:  

You must enable SNMP before you can perform this procedure.

To configure MIB information to display Object Identifiers (OIDs) in human-readable form, perform the following tasks. This procedure provides a general overview of how to complete this task using any MIB browser. Refer to the documentation for your MIB browser for specific details on how to perform this procedure:

1. Download and install a MIB browser.
2. Download and save the MIB definition file.
3. Add the MIB files to the MIB browser.
4. Open a MIB object to see the human-readable form of the OID.