Cisco Unified Serviceability Administration Guide, Release 6.1(1)
Understanding Simple Network Management Protocol
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Understanding Simple Network Management Protocol

Table Of Contents

Understanding Simple Network Management Protocol

Simple Network Management Protocol Support

SNMP Basics

SNMP version 1 Support

SNMP version 2c Support

SNMP version 3 Support

SNMP Services

SNMP Community Strings and Users

SNMP Traps and Informs

SNMP Management Information Base (MIB)

SNMP Trace Configuration

SNMP Configuration Checklist

Troubleshooting

Where to Find More Information


Understanding Simple Network Management Protocol


This chapter provides information on the following topics:

Simple Network Management Protocol Support

SNMP Basics

SNMP version 1 Support

SNMP version 2c Support

SNMP version 3 Support

SNMP Services

SNMP Community Strings and Users

SNMP Management Information Base (MIB)

SNMP Traps and Informs

SNMP Trace Configuration

SNMP Configuration Checklist

Troubleshooting

Where to Find More Information

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.

You use Cisco Unified Serviceability to configure SNMP-associated settings, such as community strings, users, and notification destinations for V1, V2c, and V3. Likewise, in the SNMP configuration windows, you can apply the settings to all nodes in the cluster.


Tip SNMP configuration parameters that you specified in Cisco Unified CallManager or Cisco Unified Communications Manager 4.X do not migrate during the Cisco Unified Communications Manager 6.0 upgrade. You must perform the SNMP configuration procedures again in Cisco Unified Serviceability.


This section contains information on the following topics:

SNMP Basics

SNMP version 1 Support

SNMP version 2c Support

SNMP version 3 Support

SNMP Services

SNMP Community Strings and Users

SNMP Management Information Base (MIB)

SNMP Traps and Informs

SNMP Basics

An SNMP-managed network comprises three key components: managed devices, agents, and network management systems.

Managed device—A network node that contains an SNMP agent and resides on a managed network. Managed devices collect and store management information and make it available by using SNMP.

The first node in the Cisco Unified Communications Manager cluster acts as the managed device.

Agent—A network-managed software module that resides on a managed device. An agent contains local knowledge of management information and translates it into a form that is compatible with SNMP.

Cisco Unified Communications Manager uses 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).

Network Management System (NMS)—A SNMP management application (together with the PC on which it runs) that provides the bulk of the processing and memory resources that are required for network management. An NMS executes applications that monitor and control managed devices. Cisco Unified Communications Manager works with the following NMS:

CiscoWorks2000

HP OpenView

Third-party applications that support SNMP and Cisco Unified Communications Manager SNMP interfaces

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

To support SNMP, you must use the following services, which display in the Service Activation and/or Control Center windows in Cisco Unified Serviceability. For a description of each service, see the "Understanding Services" section on page 9-1.

Cisco CallManager SNMP service

SNMP Master Agent

MIB2 Agent

Host Resources Agent

System Application Agent

Native Agent Adaptor

Cisco CDP Agent

Cisco Syslog Agent


Caution Stopping any SNMP service may result in loss of data because the network management system no longer monitors the Cisco Unified Communications Manager network. Do not stop the services unless your technical support team tells you to do so .

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.

For some alarms, if the routing list in the alarm definition displays SNMP traps, the CCMAgent receives alarm notifications from the alarms. The notifications are received as XML messages which are parsed and traps are sent. In the case of Phone Failed and Phone Status events, the Phone Failed and Phone Status MMFs are populated. For all other notifications, traps are sent immediately if the corresponding trap flags are enabled. In the case of the syslog agent, the CallManager alarms and system level log messages are sent to syslog daemon for logging. Also, some standard third-party applications send the log messages to syslog daemon for logging. These log messages are logged locally in the syslog files and are also 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:

Cisco Unified CallManager failed

Phone failed

Phones status update

Gateway failed

Media resource list exhausted

Route list exhausted

Gateway layer 2 change

Quality report

Malicious call

Syslog message generated


Tip Before you configure notification destination, verify that the required SNMP services are activated and running. Also, make sure that you configured the privileges for the community string/user correctly.

You configure the SNMP trap destination by choosing SNMP > V1/V2 > Notification Destination or SNMP > V3> Notification Destination in Cisco Unified Serviceability.


Table 14-1 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 14-1 by issuing the appropriate commands on the NMS, as described in the SNMP product documentation that supports the NMS.


Note Be aware that all of the parameters that are listed in Table 14-1 are part of CISCO-CCM-MIB except for the last two. The last two, clogNotificationsEnabled and clogMaxSeverity, comprise part of CISCO-SYSLOG-MIB.


Table 14-1 Cisco Unified Communications Manager Trap/Inform Configuration Parameters 

Parameter Name
Default Value
Generated Traps
Configuration Recommendations

ccmCallManagerAlarmEnable

True

ccmCallManagerFailed

ccmMediaResourceListExhausted

ccmRouteListExhausted

ccmTLSConnectionFailure

Keep the default specification.

ccmGatewayAlarmEnable

True

ccmGatewayFailed

ccmGatewayLayer2Change

Note Although you can configure a Cisco ATA 186 device as a phone in Cisco Unified Communications Manager Administration, when Cisco Unified Communications Manager sends SNMP traps for the Cisco ATA device, it sends a gateway type trap; for example, ccmGatewayFailed.

None. The default specifies this trap as enabled.

ccmPhoneStatusUpdateStorePeriod

ccmPhoneStatusUpdateAlarmInterval

1800

0

ccmPhoneStatusUpdate

Set the ccmPhoneStatusUpdateAlarmInterval to a value between 30 and 3600.

ccmPhoneFailedStorePeriod

ccmPhoneFailedAlarmInterval

1800

0

ccmPhoneFailed

Set the ccmPhoneFailedAlarmInterval to a value between 30 and 3600.

ccmMaliciousCallAlarmEnable

True

ccmMaliciousCall

None. The default specifies this trap as enabled.

ccmQualityReportAlarmEnable

True

Note This trap gets generated only if the Cisco Extended Functions service is activated and running on the local Cisco Unified Communications Manager node.

ccmQualityReport

None. The default specifies this trap as enabled.

clogNotificationsEnabled

False

clogMessageGenerated

To enable trap generation, set clogNotificationsEnable to True.

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.


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).

The Simple Network Management Protocol (SNMP) extension agent resides in each Cisco Unified Communications Managernode and exposes the CISCO-CCM-MIB that provides detailed information about devices that are known to the node. The CISCO-CCM-MIB provides device information such as device registration status, IP address, description, and model type for the node (not the cluster).

Cisco Unified Communications Manager 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 to advertise itself to other Cisco devices on the network.

The CDP subagent implements the CDP-MIB. The CDP-MIB contains the following objects:

cdpInterfaceIfIndex

cdpInterfaceMessageInterval

CdpInterfaceEnable

cdpInterfaceGroup

cdpInterfacePort

CdpGlobalRun

CdpGlobalMessageInterval

CdpGlobalHoldTime

cdpGlobalLastChange

cdpGobalDeviceId

cdpGlobalDeviceIdFormat

cdpGlobalDeviceIdFormatCpd

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:

sysApplInstalled

sysApplRun

sysApplMap

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:

system

interfaces

at

ip

icmp

tcp

udp

snmp

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:

hrSystem

hrStorage

hrDevice

hrSWRun

hrSWRunPerf

hrSWInstalled

CISCO-SYSLOG-MIB

The system supports trap functionality only. The Cisco Syslog Agent supports only the following objects of CISCO-SYSLOG-MIB:

clogNotificationsSent

clogNotificationsEnabled

clogMaxSeverity

clogMsgIgnores

clogMsgDrops

CISCO-CCM-MIB

The CISCO-CCM-MIB contains both dynamic (real-time) and configured (static) information about the local Cisco Unified Communications Managerand its associated devices, such as phones, gateways, and so on. Simple Network Management Protocol (SNMP) tables contain information such as IP address, registration status, and model type.

To view the support lists for the CISCO-CCM-MIB, go to the following link:

ftp://ftp.cisco.com/pub/mibs/supportlists/callmanager/callmanager-supportlist.html

The following list of tables exists in the CISCO-CCM-MIB:

ccmPhoneFailedTable, ccmPhoneStatusUpdateTable, ccmPhoneExtnTable, ccmPhoneTable

For the Cisco Unified IP Phone, the number of registered phones in ccmPhoneTable should match Cisco Unified Communications Manager/RegisteredHardware Phones perfmon counter. The ccmPhoneTable includes one entry for each registered, unregistered, or rejected Cisco Unified IP Phone.

ccmCTIDeviceTable, ccmCTIDeviceDirNumTable

The ccmCTIDeviceTable stores each CTI device as one device. Based on the registration status of the CTI Route Point or CTI Port, the ccmRegisteredCTIDevices, ccmUnregisteredCTIDevices, and ccmRejectedCTIDevices counters in the Cisco Unified Communications Manager MIB get updated.

ccmSIPDeviceTable

The CCMSIPDeviceTable stores each SIP trunk as one device.

ccmH323Device

The ccmH323DeviceTable contains the list of H323 devices for which the local Cisco Unified Communications Manager contains information. For H.323 phones or H.323 gateways, the ccmH.323DeviceTable contains one entry for each H.323 device. (The H.323 phone and gateway do not register with Cisco Unified Communications Manager. Cisco Unified Communications Manager generates the H.323Started alarm when it is ready to handle calls for the indicated H.323 phone and gateway.) The system provides the gatekeeper information as part of the H323 trunk information.

ccmVoiceMailDeviceTable, ccmVoiceMailDirNumTable

For Cisco uOne, ActiveVoice, the ccmVoiceMailDeviceTable has one entry for each voice-messaging device. Based on the registration status, the ccmRegisteredVoiceMailDevices, ccmUnregisteredVoiceMailDevices, and ccmRejectedVoiceMailDevices counters in the Cisco Unified Communications Manager MIB get updated.

ccmGatewayTable

The ccmRegisteredGateways, ccmUnregistered gateways, and ccmRejectedGateways keep track of the number of registered gateway devices or ports, number of unregistered gateway devices or ports, and number of rejected gateway devices or ports, respectively.

Cisco Unified Communications Manager generates alarms at the device or port level. The ccmGatewayTable, based on CallManager alarms, contains device- or port-level information. Each registered, unregistered, or rejected device or port has one entry in ccmGatewayTable. The VG200 with two FXS ports and one T1 port has three entries in ccmGatewayTable. The ccmActiveGateway and ccmInActiveGateway counters track number of active (registered) and lost contact with (unregistered or rejected) gateway devices or ports.

Based on the registration status, ccmRegisteredGateways, ccmUnregisteredGateways, and ccmRejectedGateways counters get updated.

ccmProductTypeTable

The table contains the list of product types that are supported in a Cisco Unified Communications Manager cluster, including phone types, gateway types, media device types, H323 device types, CTI device types, voice-messaging device types and SIP device types.

ccmMediaDeviceInfo Table

The table contains a list of all media devices which have tried to register with the local CallManager at least once.


Note The dynamic tables such as phoneTable, gatewayTable, and so on, get populated only if the local Cisco CallManager service is up and running. The static tables such as region, timezone, devicepool, and so on, in the Cisco Unified Communications Manager MIB, get populated when the Cisco CallManager SNMP service is running.



Note The "ccmAlarmConfigInfo" and "ccmQualityReportAlarmConfigInfo" groups in the CISCO-CCM-MIB define the configuration parameters that relate to the notifications that the "SNMP Traps and Informs" section describes.


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 are developed by the hardware vendors; 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:

Table 14-2—Describes supported IBM MIBs

Table 14-3—Describes supported HP MIBs

Table 14-2 IBM MIBs 

MIB
OID
Description
Supported for browsing only

IBM-SYSTEM-HEALTH-MIB

1.3.6.1.4.1.2.6.159.1.1.30

Provides temperature, voltage, and fan status

IBM-SYSTEM-ASSETID-MIB

1.3.6.1.4.1.2.6.159.1.1.60

Provides hardware component asset data

IBM-SYSTEM-LMSENSOR-MIB

1.3.6.1.4.1.2.6.159.1.1.80

Provides temperature, voltage, and fan details

IBM-SYSTEM-NETWORK-MIB

1.3.6.1.4.1.2.6.159.1.1.110

Provides Network Interface Card (NIC) status

IBM-SYSTEM-MEMORY-MIB

1.3.6.1.4.1.2.6.159.1.1.120

Provides physical memory details

IBM-SYSTEM-POWER-MIB

1.3.6.1.4.1.2.6.159.1.1.130

Provides power supply details

IBM-SYSTEM-PROCESSOR-MIB

1.3.6.1.4.1.2.6.159.1.1.140

Provides CPU asset/status data

Supported for system traps

IBM-SYSTEM-TRAP

1.3.6.1.4.1.2.6.159.1.1.0

Provides temperature, voltage, fan, disk, NIC, memory, power supply, and CPU details

IBM-SYSTEM-RAID-MIB

1.3.6.1.4.1.2.6.167.2

Provides RAID status


Table 14-3 HP MIBs 

MIB
OID
Description
Supported for browsing and system traps

CPQSTDEQ-MIB

1.3.6.1.4.1.232.1

Provides hardware component configuration data

CPQSINFO-MIB

1.3.6.1.4.1.232.2

Provides hardware component asset data

CPQIDA-MIB

1.3.6.1.4.1.232.3

Provides RAID status/events

CPQHLTH-MIB

1.3.6.1.4.1.232.6

Provides hardware components status/events

CPQSTSYS-MIB

1.3.6.1.4.1.232.8

Provides storage (disk) systems status/events

CPQSM2-MIB

1.3.6.1.4.1.232.9

Provides iLO status/events

CPQTHRSH-MIB

1.3.6.1.4.1.232.10

Provides alarm threshold management

CPQHOST-MIB

1.3.6.1.4.1.232.11

Provides operating system information

CPQIDE-MIB

1.3.6.1.4.1.232.14

Provides IDE (CD-ROM) drive status/events

CPQNIC-MIB

1.3.6.1.4.1.232.18

Provides Network Interface Card (NIC) status/events


SNMP Trace Configuration

In the Trace Configuration window in Cisco Unified Serviceability, you can configure trace for the Cisco CM agent 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 Cisco Unified Communications Operating System Administration Guide.

SNMP Configuration Checklist

Table 14-4 provides an overview of the steps for configuring SNMP.

Table 14-4 SNMP Configuration Checklist 

Configuration Steps
Related Procedures and Topics

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.

SNMP Services

Understanding Services, page 9-1

Configuring Services, page 11-1

Step 3 

In the Service Activation window, activate the Cisco CallManager SNMP service.

SNMP Services

Understanding Services, page 9-1

Activating and Deactivating Feature Services, page 11-1

Step 4 

If you are using SNMP v1/v2c, configure the community string.

Configuring a Community String, page 15-2

Step 5 

If you are using SNMP v3, configure the SNMP user.

Configuring the SNMP User, page 16-2

Step 6 

Configure the notification destination for traps or informs.

For SNMP v1/v2c—Configuring a Notification Destination for SNMP V1/V2c, page 15-6

For SNMP v3—Configuring a Notification Destination for SNMP V3, page 16-6

SNMP Traps and Informs

Step 7 

Configure the system contact and location for the MIB2 system group.

Configuring the MIB2 System Group, page 17-1

Step 8 

Restart the Master Agent service.

SNMP Services

Understanding Services, page 9-1

Understanding Services, page 9-1

Step 9 

On the NMS, configure the Cisco Unified Communications Manager trap parameters.

SNMP Traps and Informs

SNMP product documentation that supports the NMS

Troubleshooting

Review this section for troubleshooting tips.

Make sure that all of the feature and network services listed in "SNMP Services" section are running.

Cannot poll any MIBs from the system

This condition means that the community string or the snmp user is not configured on the system or they do not match with what is configured on the system.


Note By default, no community string or user is configured on the system.


Check whether the community string or snmp user is properly configured on the system by using the SNMP configuration windows.

Cannot receive any notifications from the system

This condition means that the notification destination is not configured correctly on the system.

Verify that you configured the notification destination properly in the Notification Destination (V1/V2c or V3) Configuration window.

Where to Find More Information

Related Topics

Understanding Services, page 9-1

Configuring Services, page 11-1

Configuring SNMP V1/V2c, page 15-1

Configuring SNMP V3, page 16-1

Configuring the MIB2 System Group, page 17-1