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Table Of Contents
Related Features and Technologies
Supported Standards, MIBs, and RFCs
Configuring MSDP MIB Notifications
Verifying MSDP MIB Configuration
Monitoring and Maintaining MSDP
MSDP MIB
This feature module describes the MSDP MIB support added for SNMP network monitoring in Cisco IOS Release 12.1(5)T. It includes the following sections:
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Supported Standards, MIBs, and RFCs
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Feature Overview
Multicast Source Discovery Protocol (MSDP) is a mechanism to connect multiple Protocol Independent Multicast sparse-mode (PIM-SM) domains. MSDP allows multicast sources for a group to be known to all rendezvous points (RPs) in different domains. Each PIM-SM domain uses its own RPs and need not depend on RPs in other domains. An RP (or other MSDP SA originator) runs MSDP over TCP to discover multicast sources in other domains. MSDP support was implemented in Cisco IOS Release 12.0(7)T.
The MSDP MIB describes managed objects that can be used to remotely monitor MSDP speakers using SNMP.
The MSDP MIB module contains four scalar objects and three tables. The tables are the Requests table, the Peer table, and the Source-Active (SA) Cache table. The Cisco implementation supports the Peer table and SA Cache table only. The Requests table contains information used to determine which peer to send SA requests to. However, the MSDP implementation used in Cisco IOS software does not associate sending SA requests to peers with group addresses (or group address masks).
Benefits
This feature allows the monitoring of MSDP activity using SNMP. Typically SNMP monitoring is performed using a Network Management System (NMS).
Restrictions
All MSDP-MIB objects are implemented as read-only.
The Requests table is not supported in Cisco's implementation of the MSDP MIB.
The msdpEstablished notification is not supported in Cisco's implementation of the MSDP MIB.
Related Features and Technologies
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Related Documents
For information on MSDP and the MSDP MIB, see the following Internet Draft documents (available at www.ietf.org):
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Farinacci, D., Rekhter, Y., Meyer, D., Lothberg, P., Kilmer, H., and Hall, J.•
(Note that Cisco currently supports only Draft 3 of the MIB)For information on configuring MSDP on your Cisco devices, see the Cisco IOS Release 12.0(7)T feature module titled "Multicast Source Discovery Protocol," available on Cisco Connection Online.
For information on configuring SNMP using Cisco IOS software, see the following documents:
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For information on using SNMP MIB features, see the appropriate documentation for your network management system.
For complete implementation details of the MSDP MIB, see the file MSDP-MIB.my, available from Cisco.com at http://www.cisco.com/public/mibs/v2/.
Supported Platforms
MSDP MIB functionality is available only in software images that support MSDP, IP multicast, and SNMP. Supported platforms include:
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Supported Standards, MIBs, and RFCs
Standards
No new or modified standards are supported by this feature.
MIBs
This feature introduces the MSDP MIB.
The MSDP-MIB.my file can be downloaded from the Cisco MIB web site on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
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Prerequisites
The tasks in this document assume that you have configured SNMP and MSDP on your devices.
In each PIM-SM domain there should be a device that is configured as the MSDP speaker. This device must have SNMP enabled and must have the MSDP MIB available.
All MSDP speakers should have an IP address configured in order to support SNMP Get operations.
Configuration Tasks
See the following sections for configuration tasks for the MSDP MIB feature. Each task in the list is identified as optional or required.
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Configuring MSDP MIB Notifications
To control the generation of MSDP traps or informs on a device, use any of the following commands in global configuration mode:
Note that MSDP MIB notifications do not have to be enabled on a system to process simple Set or Get SNMP requests.
Verifying MSDP MIB Configuration
Use the more system:running-config or the show running-config command to verify that the desired snmp-server commands are in your configuration file.
Troubleshooting Tips
You can compare the results of MSDP MIB notifications to the output from the Cisco IOS software by using the show ip msdp summary and show ip msdp peer CLI commands on the appropriate routing device. You can also compare the results of these commands to the results from SNMP Get operations. You can verify Source-Active (SA) Cache table entries using the show ip msdp sa-cache Cisco IOS CLI command. Additional troubleshooting information, such as the local address of the connection, the local port, and the remote port, and be obtained using the output from the debug ip msdp command.
Monitoring and Maintaining MSDP
The MSDP MIB feature is designed to provide information to network management applications (typically graphical-user-interface programs running on an external network management system). MSDP MIB objects can be read by the NMS using SNMP Get, Get-next, and Get-bulk operations.
Configuration Examples
The following example shows a configuration session on one of the Cisco devices serving as a speaker in a PIM-SM domain. MSDP MIB traps are enabled to be sent to the host specified by the name myhost.cisco.com. The community string is defined as public.
Router# configure terminalRouter(config)# snmp-server community public roRouter(config)# snmp-server enable traps msdpRouter(config)# snmp-server host myhost.cisco.com traps version 2c public msdpCommand Reference
This section documents the following modified commands:
All other commands used with this feature are documented in the Cisco IOS Release 12.1 command reference publications.
snmp-server enable traps
To enable the router to send Simple Network Management Protocol (SNMP) traps or informs (notifications), use the snmp-server enable traps global configuration command. To disable SNMP notifications, use the no form of this command.
snmp-server enable traps [notification-type] [notification-option]
no snmp-server enable traps [notification-type] [notification-option]
Syntax Description
Defaults
SNMP notifications are disabled.
If you enter this command with no notification-type keywords, the default is to enable all available notification types controlled by this command.
Command Modes
Global configuration
Command History
Usage Guidelines
The no form of the snmp-server enable traps command is useful for disabling notifications that are generating a large amount of unneeded noise on your network.
SNMP notifications can be sent as traps or inform requests. This command enables both traps and inform requests for the specified notification types. The notification types available on your routing device will vary depending on the Cisco IOS software image.
If you do not enter an snmp-server enable traps command, no notifications controlled by this command are sent. To configure the router to send these SNMP notifications, you must enter at least one snmp-server enable traps command. If you enter the command with no keywords, all notification types are enabled. If you enter the command with a keyword, only the notification type related to that keyword is enabled. To enable multiple types of notifications, you must issue a separate snmp-server enable traps command for each notification type and notification option.
The snmp-server enable traps command is used in conjunction with the snmp-server host command. Use the snmp-server host command to specify which host or hosts receive SNMP notifications. To send notifications, you must configure at least one snmp-server host command.
For a host to receive a notification controlled by this command, both the snmp-server enable traps command and the snmp-server host command for that host must be enabled. If the notification type is not controlled by this command, just the appropriate snmp-server host command must be enabled.
The notification types used in this command all have an associated MIB object that allows them to be enabled or disabled (for example, HSRP traps are defined using the HSRP MIB, repeater traps are defined using the Repeater Hub MIB, and so on). Not all of the notification types available in the snmp-server host command have notificationEnable MIB objects, so some notification types cannot be controlled using the snmp-server enable traps command.
Examples
The following example enables the router to send all traps to the host "myhost.cisco.com" using the community string defined as public:
snmp-server enable trapssnmp-server host myhost.cisco.com publicThe following example enables the router to send Frame Relay and environmental monitor traps to the host myhost.cisco.com using the community string public:
snmp-server enable traps frame-relaysnmp-server enable traps envmon temperaturesnmp-server host myhost.cisco.com publicThe following example will not send traps to any host. The BGP traps are enabled for all hosts, but the only traps enabled to be sent to a host are ISDN traps (which are not enabled in this example).
snmp-server enable traps bgpsnmp-server host bob public isdnThe following example enables the router to send all inform requests to the host "myhost.cisco.com" using the community string defined as public:
snmp-server enable trapssnmp-server host myhost.cisco.com informs version 2c publicThe following example sends HSRP MIB traps to the host myhost.cisco.com using the community string public.
snmp-server enable hsrpsnmp-server host myhost.cisco.com traps version 2c public hsrpRelated Commands
snmp-server host
To specify the recipient of a Simple Network Management Protocol (SNMP) notification operation, use the snmp-server host global configuration command. To remove the specified host from the configuration, use the no form of this command.
snmp-server host host [traps | informs] [version {1 | 2c | 3 [auth | priv | noauth]}] community-string [udp-port port-number] [notification-type]
no snmp-server host host [traps | informs] [notification-type]
Syntax Description
Defaults
This command is disabled by default (no notifications are sent).
If you enter this command with no keywords, the default is to send all trap types to the host. No informs will be sent to this host.
If no version keyword is present, the default is version 1. If no traps or informs keyword is present, traps are enabled.
The no snmp-server host command with no keywords specified will disable traps, but not informs, to the host. To disable informs, use the no snmp-server host informs command.
Command Modes
Global configuration
Command History
10.0
This command was introduced.
12.1(3)T
The hsrp keyword was added for the Cisco IOS Release 12.1 T train.
12.1(5)T
The msdp keyword was added.
Usage Guidelines
SNMP notifications can be sent as traps or inform requests. Traps are unreliable because the receiver does not send acknowledgments when it receives traps. The sender cannot determine if the traps were received. However, an SNMP entity that receives an inform request acknowledges the message with an SNMP response protocol data unit (PDU). If the sender never receives the response, the inform request can be sent again. Thus, informs are more likely to reach their intended destination.
However, informs consume more resources in the agent and in the network. Unlike a trap, which is discarded as soon as it is sent, an inform request must be held in memory until a response is received or the request times out. Also, traps are sent only once, while an inform may be retried several times. The retries increase traffic and contribute to a higher overhead on the network.
If you do not enter an snmp-server host command, no notifications controlled by this command are sent. To configure the router to send those SNMP notifications, you must enter at least one snmp-server host command. If you enter the command with no keywords, all trap types are enabled for the host. To enable multiple hosts, you must issue a separate snmp-server host command for each host. You can specify multiple notification types in the command for each host.
When multiple snmp-server host commands are given for the same host and kind of notification (trap or inform), each succeeding command overwrites the previous command. Only the last snmp-server host command will be in effect. For example, if you enter an snmp-server host informs command for a host and then enter another snmp-server host informs command for the same host, the second command will replace the first.
The snmp-server host command is used in conjunction with the snmp-server enable command. Use the snmp-server enable command to specify which SNMP notifications are sent globally. For a host to receive most notifications, at least one snmp-server enable command and the snmp-server host command for that host must be enabled.
However, some notification types cannot be controlled with the snmp-server enable command. For example, some notification types are always enabled. Other notification types are enabled by a different command. For example, the linkUpDown notifications are controlled by the snmp trap link-status command. These notification types do not require an snmp-server enable command.
The availability of a notification type option depends on the router type and Cisco IOS software features supported on the router. For example, the envmon notification type is available only if the environmental monitor is part of the system (for example, the Cisco 12000 series GSR platforms use the environmental monitor).
Examples
The following example sends HSRP MIB traps to the host "myhost.cisco.com". The community string is defined as public.
snmp-server enable traps hsrpsnmp-server host myhost.cisco.com traps version 2c public hsrpThe following example sends the SNMP traps defined in RFC 1157 to the host "myhost.cisco.com". The community string is defined as comaccess.
snmp-server enable trapssnmp-server host myhost.cisco.com comaccess snmpThe following example sends the SNMP and Cisco environmental monitor enterprise-specific traps to address 172.30.2.160:
snmp-server enable trapssnmp-server host 172.30.2.160 public snmp envmonThe following example enables the router to send all traps to the host myhost.cisco.com using the community string public:
snmp-server enable trapssnmp-server host myhost.cisco.com publicThe following example will not send traps to any host. The BGP traps are enabled for all hosts, but only the ISDN traps are enabled to be sent to a host.
snmp-server enable traps bgpsnmp-server host bob public isdnThe following example enables the router to send all inform requests to the host myhost.cisco.com using the community string public:
snmp-server enable trapssnmp-server host myhost.cisco.com informs version 2c publicRelated Commands
Glossary
inform—An SNMP trap message which includes a delivery confirmation request. See "trap."
MIB—Management Information Base. Database of network management information that is used and maintained by a network management protocol such as SNMP. The value of a MIB object can be changed or retrieved using SNMP commands, usually through a Network Management System (NMS). MIB objects are organized in a tree structure that includes public (standard) and private (proprietary) branches.
MSDP—Multicast Source Discovery Protocol. A mechanism to connect multiple PIM sparse-mode (SM) domains. MSDP allows multicast sources for a group to be known to all rendezvous point(s) (RPs) in different domains. Each PIM-SM domain uses its own RPs and need not depend on RPs in other domains. An RP runs MSDP over TCP to discover multicast sources in other domains.
NMS—Network Management System. An application or suite of applications designed to monitor networks using SNMP. CiscoView is one example of an NMS.
OID—Object Identifier. The values for OIDs are defined in specific MIB modules.
PIM—Protocol Independent Multicast. Multicast routing architecture that allows the addition of IP multicast routing on existing IP networks. PIM is unicast routing protocol independent and can be operated in two modes: PIM dense mode (PIM-DM) and PIM sparce mode (PIM-SM).
PDU—Protocol Data Unit. Refers to the information contained in an SNMP message. The SNMP PDU type identifies the type of message (trap or inform) being sent.
SNMP—Simple Network Management Protocol. Management protocol used almost exclusively in TCP/IP networks. SNMP provides a means to monitor and control network devices, and to manage configurations, statistics collection, performance, and security, typically through the use of a NMS.
trap—Message sent by an SNMP agent to a network management station, console, or terminal to indicate the occurrence of a significant event, such as a specifically defined condition or a threshold that was reached.