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Table Of Contents
Understanding Simple Network Management Protocol
Simple Network Management Protocol Support
SNMP Configuration Requirements
SNMP Community Strings and Users
SNMP Management Information Base (MIB)
Where to Find More Information
Understanding Simple Network Management Protocol
This chapter provides information on the following topics:
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Simple Network Management Protocol Support
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Simple Network Management Protocol Support
SNMP, an application layer protocol, facilitates the exchange of management information among network devices, such as nodes, routers, and so on. As part of the TCP/IP protocol suite, SNMP enables administrators to remotely manage network performance, find and solve network problems, and plan for network growth.
Cisco allows you to use any SFTP server product but recommends SFTP products that have been certified with Cisco through the Cisco Technology Developer Partner program (CTDP). CTDP partners, such as GlobalSCAPE, certify their products with specified version of Cisco Unified Communications Manager. For information on which vendors have certified their products with your version of Cisco Unified Communications Manager, refer to the following URL:
http://www.cisco.com/pcgi-bin/ctdp/Search.pl
For information on using GlobalSCAPE with supported Cisco Unified Communications versions, refer to the following URL:
http://www.globalscape.com/gsftps/cisco.aspx
Cisco uses the following servers for internal testing. You may use one of the servers, but you must contact the vendor for support:
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Titan (refer to http://www.titanftp.com/)
For issues with third-party products that have not been certified through the CTDP process, contact the third-party vendor for support.
You use Cisco Unified Serviceability to configure SNMP-associated settings, such as community strings, users, and notification destinations for V1, V2c, and V3. The settings that you configure in Cisco Unified Serviceability apply to the local node; however, if your Cisco Unified Communications Manager or Cisco Unity Connection configuration supports clusters, you can apply settings to all servers in the cluster with the "Apply to All Nodes" option in the SNMP configuration windows.
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SNMP supports IPv4, although the CISCO-CCM-MIB includes columns and storage for IPv6 addresses, preferences, and so on.
This section contains information on the following topics:
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SNMP Basics
An SNMP-managed network comprises three key components: managed devices, agents, and network management systems.
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Unified CM BE only: The server where Cisco Unified Communications Manager is installed acts as the managed device.
Unified CM only: In a configuration that supports clusters, the first node in the cluster acts as the managed device.
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Cisco Unified Communications Manager and Cisco Unity Connection use a master agent and subagent components to support SNMP. The master agent acts as the agent protocol engine and performs the authentication, authorization, access control, and privacy functions that relate to SNMP requests. Likewise, the master agent contains a few MIB variables that relate to MIB-II. The master agent also connects and disconnects subagents after the subagent completes necessary tasks. The SNMP master agent listens on port 161 and forwards SNMP packets for Vendor MIBs.
The Cisco Unified Communications Manager subagent interacts with the local Cisco Unified Communications Manager only. The Cisco Unified Communications Manager subagents send trap and information messages to the SNMP Master Agent, and the SNMP Master Agent communicates with the SNMP trap receiver (notification destination).
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SNMP Configuration Requirements
The system provides no default SNMP configuration. You must configure SNMP settings after installation to access MIB information. Cisco supports SNMP V1, V2c, and V3 versions.
SNMP agent provides security with community names and authentication traps. You must configure a community name to access MIB information. Table 15-1 provides the required SNMP configuration settings.
SNMP Version 1 Support
SNMP version 1 (SNMPv1), the initial implementation of SNMP that functions within the specifications of the Structure of Management Information (SMI), operates over protocols, such as User Datagram Protocol (UDP) and Internet Protocol (IP).
The SNMPv1 SMI defines highly structured tables (MIBs) that are used to group the instances of a tabular object (that is, an object that contains multiple variables). Tables contain zero or more rows, which are indexed, so SNMP can retrieve or alter an entire row with a supported command.
With SNMPv1, the NMS issues a request, and managed devices return responses. Agents use the Trap operation to asynchronously inform the NMS of a significant event.
In Cisco Unified Serviceability, you configure SNMP v1 support in the V1/V2c Configuration window.
SNMP Version 2c Support
As with SNMPv1, SNMPv2c functions within the specifications of the Structure of Management Information (SMI). MIB modules contain definitions of interrelated managed objects. The operations that are used in SNMPv1 are similar to those that are used in SNMPv2. The SNMPv2 Trap operation, for example, serves the same function as that used in SNMPv1, but it uses a different message format and replaces the SNMPv1 Trap.
The Inform operation in SNMPv2c allows one NMS to send trap information to another NMS and to then receive a response from the NMS.
In Cisco Unified Serviceability, you configure SNMP v2c support in the V1/V2c Configuration window.
SNMP Version 3 Support
SNMP version 3 provides security features such as authentication (verifying that the request comes from a genuine source), privacy (encryption of data), authorization (verifying that the user allows the requested operation), and access control (verifying that the user has access to the objects requested.) To prevent SNMP packets from being exposed on the network, you can configure encryption with SNMPv3.
Instead of using community strings like SNMP v1 and v2, SNMP v3 uses SNMP users, as described in the "SNMP Community Strings and Users" section.
In Cisco Unified Serviceability, you configure SNMP v3 support in the V3 Configuration window.
SNMP Services
The services in Table 15-2 support SNMP operations. For a description of each service, see the "Understanding Services" section on page 9-1.
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Caution
SNMP Community Strings and Users
Although SNMP community strings provide no security, they authenticate access to MIB objects and function as embedded passwords. You configure SNMP community strings for SNMP V1 and V2c only.
SNMP V3 does not use community strings. Instead, version 3 uses SNMP users. These users serve the same purpose as community strings, but users provide security because you can configure encryption or authentication for them.
In Cisco Unified Serviceability, no default community string or user exists.
SNMP Traps and Informs
An SNMP agent sends notifications to NMS in the form of traps or informs to identify important system events. Traps do not receive acknowledgments from the destination whereas informs do receive acknowledgments. You configure the notification destinations by using the SNMP Notification Destination Configuration windows in Cisco Unified Serviceability.
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For all notifications, the system sends traps immediately if the corresponding trap flags are enabled. In the case of the syslog agent, the CallManager alarms and system level log messages get sent to syslog daemon for logging. Also, some standard third-party applications send the log messages to syslog daemon for logging. These log messages get logged locally in the syslog files and also get converted into SNMP traps/notifications.
The following list contains Cisco Unified Communications Manager SNMP trap/inform messages that are sent to a configured trap destination:
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You configure the SNMP trap destination by choosing SNMP > V1/V2 > Notification Destination or SNMP > V3> Notification Destination in Cisco Unified Serviceability.Table 15-3 comprises information about Cisco Unified Communications Manager trap/inform parameters that you configure on the Network Management System (NMS). You can configure the values in Table 15-3 by issuing the appropriate commands on the NMS, as described in the SNMP product documentation that supports the NMS.
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Table 15-3 Cisco Unified Communications Manager Trap/Inform Configuration Parameters
ccmCallManagerAlarmEnable
True
ccmCallManagerFailed
ccmMediaResourceListExhausted
ccmRouteListExhausted
ccmTLSConnectionFailure
Keep the default specification.
ccmGatewayAlarmEnable
True
ccmGatewayFailed
ccmGatewayLayer2Change
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None. The default specifies this trap as enabled.
ccmPhoneStatusUpdateStorePeriod
ccmPhoneStatusUpdateAlarmInterval
1800
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ccmPhoneStatusUpdate
Set the ccmPhoneStatusUpdateAlarmInterval to a value between 30 and 3600. See Configuring CISCO-CCM-MIB Trap Parameters, page 19-2.
ccmPhoneFailedStorePeriod
ccmPhoneFailedAlarmInterval
1800
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ccmPhoneFailed
Set the ccmPhoneFailedAlarmInterval to a value between 30 and 3600. See Configuring CISCO-CCM-MIB Trap Parameters, page 19-2.
ccmMaliciousCallAlarmEnable
True
ccmMaliciousCall
None. The default specifies this trap as enabled.
ccmQualityReportAlarmEnable
True
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ccmQualityReport
None. The default specifies this trap as enabled.
clogNotificationsEnabled
False
clogMessageGenerated
To enable trap generation, set clogNotificationsEnable to True. See Configuring CISCO-SYSLOG-MIB Trap Parameters, page 19-1.
clogMaxSeverity
Warning
clogMessageGenerated
When you set clogMaxSeverity to warning, a SNMP trap generates when Cisco Unified Communications Manager applications generate a syslog message with at least a warning severity level.Configuring CISCO-SYSLOG-MIB Trap Parameters, page 19-1.
SNMP Management Information Base (MIB)
SNMP allows access to Management Information Base (MIB), which is a collection of information that is organized hierarchically. MIBs comprise managed objects, which are identified by object identifiers. A MIB object, which contains specific characteristics of a managed device, comprises one or more object instances (variables).
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The SNMP interface provides these Cisco Standard MIBs:
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The Simple Network Management Protocol (SNMP) extension agent resides in the server and exposes the CISCO-CCM-MIB, which provides detailed information about devices that are known to the server. In the case of a cluster configuration, the SNMP extension agent resides in each server in the cluster. The CISCO-CCM-MIB provides device information such as device registration status, IP address, description, and model type for the server (not the cluster, in a configuration that supports clusters).
The SNMP interface also provides these Industry Standard MIBs:
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For vendor-specific supported hardware MIBS, refer to the "Vendor-Specific MIBs" section.
Cisco Unified Communications Manager SNMP Interface supports the following MIBs.
CISCO-CDP-MIB
Use the Cisco Unified Communications Manager CDP subagent to read the Cisco Discovery Protocol MIB, CISCO-CDP-MIB. This MIB enables Cisco Unified Communications Manager and Cisco Unity Connection to advertise themselves to other Cisco devices on the network.
The CDP subagent implements the CDP-MIB. The CDP-MIB contains the following objects:
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SYSAPPL-MIB
Use the System Application Agent to get information from the SYSAPPL-MIB, such as installed applications, application components, and processes that are running on the system.
System Application Agent supports the following object groups of SYSAPPL-MIB:
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MIB-II
Use MIB2 agent to get information from MIB-II. The MIB2 agent provides access to variables that are defined in RFC 1213, such as interfaces, IP, and so on, and supports the following groups of objects:
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HOST-RESOURCES MIB
Use Host Resources Agent to get values from HOST-RESOURCES-MIB. The Host Resources Agent provides SNMP access to host information, such as storage resources, process tables, device information, and installed software base. The Host Resources Agent supports the following groups of objects:
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CISCO-SYSLOG-MIB
Syslog tracks and logs all system messages, from informational through critical. With this MIB, network management applications can receive syslog messages as SNMP traps:
The Cisco Syslog Agent supports trap functionality with the following MIB objects:
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CISCO-CCM-MIB/CISCO-CCM-CAPABILITY MIB
The CISCO-CCM-MIB contains both dynamic (real-time) and configured (static) information about the Cisco Unified Communications Manager and its associated devices, such as phones, gateways, and so on, that are visible on this Cisco Unified Communications Manager node. Simple Network Management Protocol (SNMP) tables contain information such as IP address, registration status, and model type.
SNMP supports IPv4, although the CISCO-CCM-MIB includes columns and storage for IPv6 addresses, preferences, and so on.
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To view the support lists for the CISCO-CCM-MIB and MIB definitions, go to the following link:
ftp://ftp.cisco.com/pub/mibs/supportlists/callmanager/callmanager-supportlist.html
To view MIB dependencies and MIB contents, including obsolete objects, across Cisco Unified Communications Manager releases, go to the following link: http://tools.cisco.com/Support/SNMP/do/BrowseMIB.do?local=en&step=2&mibName=CISCO-CCM-CAPABILITY
Dynamic tables (see Table 15-4) get populated only if the Cisco CallManager service is up and running (or the local Cisco CallManager service in the case of a Cisco Unified Communications Manager cluster configuration); static tables (see Table 15-5) get populated when the Cisco CallManager SNMP Service is running.
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CISCO-UNITY-MIB
The CISCO-UNITY-MIB uses the Connection SNMP Agent to get information about Cisco Unity Connection.
To view the CISCO-UNITY-MIB definitions, go to the following link and click SNMP V2 MIBs:
http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml
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The Connection SNMP Agent supports the following objects.
Vendor-Specific MIBs
The following MIBs exist on various Cisco MCS, depending on vendor and model number. To query these MIBS, you can use the standard MIB browsers that the hardware vendors develop; for example, HP Systems Insight Manager (SIM) and IBM Director Server+Console. For information on using the MIB browsers, refer to the documentation that the hardware vendor provides.
To review the vendor-specific MIB information, see the following tables:
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SNMP Trace Configuration
For Cisco Unified Communications Manager, you can configure trace for the Cisco CallManager SNMP agent in the Trace Configuration window in Cisco Unified Serviceability by choosing the Cisco CallManager SNMP Service in the Performance and Monitoring Services service group. A default setting exists for all the agents. For Cisco CDP Agent and Cisco Syslog Agent, you use the CLI to change trace settings, as described in the Command Line Interface Reference Guide for Cisco Unified Solutions.
For Cisco Unity Connection, you can configure trace for the Connection SNMP agent in the Trace Configuration window in Cisco Unity Connection Serviceability by choosing the Connection SNMP Agent component.
SNMP Configuration Checklist
Table 15-9 provides an overview of the steps for configuring SNMP.
Table 15-9 SNMP Configuration Checklist
Step 1
Install and configure the SNMP NMS.
SNMP product documentation that supports the NMS
Step 2
In the Control Center—Network Services window, verify that the system started the SNMP services.
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Unified CM and Unified CM BE only: In the Service Activation window, activate the Cisco CallManager SNMP service.
Connection only: The Connection SNMP Agent service automatically activates.
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Step 4
If you are using SNMP V1/V2c, configure the community string.
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If you are using SNMP V3, configure the SNMP user.
Step 6
Configure the notification destination for traps or informs.
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Configure the system contact and location for the MIB2 system group.
Step 8
Configure trap settings for CISCO-SYSLOG-MIB.
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Unified CM and Unified BE only: Configure trap settings for CISCO-CCM-MIB.
Step 10
Restart the Master Agent service.
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Step 11
On the NMS, configure the Cisco Unified Communications Manager trap parameters.
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Where to Find More Information
Related Topics
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