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Table Of Contents
Configuring CNS Security Features
Enabling and Configuring the CNS Agents
Configuring Advanced CNS Features
Monitoring and Verifying the CNS Agents
Configuration Examples for CNS Agents
Deploying the CNS Router: Example
Configuring a Partial Configuration: Example
Enabling and Configuring CNS Agents: Example
cns notifications encapsulation
CNS Agents
CNS agents is a collection of services that can provide remote event-driven configuring of Cisco IOS networking devices and remote execution of some command-line interface (CLI) commands.
Feature History for the CNS Feature
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Contents
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Configuration Examples for CNS Agents
Prerequisites for CNS Agents
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Table 1 Router Interface and Transport Protocols Required by CNS Services
T1
Yes
Yes
Yes
ADSL
No
Yes
Yes
Serial
Yes
No
Yes
Restrictions for CNS Agents
Remote Router
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–
–
CNS Configuration Engine
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•
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Information About CNS Agents
To configure CNS agents, you should understand the following concepts:
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CNS
CNS is a foundation technology for linking users to networking services and provides the infrastructure for the automated configuration of large numbers of network devices. Many IP networks are quite complex with many devices, and each device must currently be configured individually. When standard configurations do not exist or have been modified, the time involved in initial installation and subsequent upgrading is considerable. The volume of smaller, more standardized, customer networks is also growing faster than the number of available network engineers. Internet service providers (ISPs) now need a method for sending out partial configurations to introduce new services. To address all these issues, CNS has been designed to provide "plug-and-play" network services using a central directory service and distributed agents. CNS features include CNS configuration and event agents and a flow-through provisioning structure. The configuration and event agents use a CNS configuration engine to provide methods for automating initial Cisco IOS device configurations, incremental configurations, and synchronized configuration updates, and the configuration engine reports the status of the configuration load as an event to which a network monitoring or workflow application can subscribe. The CNS flow-through provisioning uses the CNS configuration and event agents to provide an automated workflow, eliminating the need for an on-site technician.
CNS Configuration Agent
The CNS configuration agent is involved in the initial configuration and subsequent partial configurations on a Cisco IOS device. To activate the CNS configuration agent, enter any of the cns config command-line interface (CLI) commands.
CNS Exec Agent
The CNS exec agent allows a remote application to execute an EXEC mode CLI command on a Cisco IOS device by sending an event message that contains the command. A restricted set of EXEC CLI commands—show commands—is supported.
CNS Event Agent
Although other CNS agents may be configured, no other CNS agents are operational until the cns event command is entered because the CNS event agent provides a transport connection to the CNS event bus for all other CNS agents. The other CNS agents use the connection to the CNS event bus to send and receive messages. The CNS event agent does not read or modify the messages.
Initial CNS Configuration
When a routing device first comes up, it connects to the configuration server component of the CNS configuration agent by establishing a TCP connection through the use of cns config initial, a standard command-line interface (CLI) command. The device issues a request and identifies itself by providing a unique configuration ID to the configuration server.
When the CNS web server receives a request for a configuration file, it invokes the Java servlet and executes the corresponding embedded code. The embedded code directs the CNS web server to access the directory server and file system to read the configuration reference for this device (configuration ID) and template. The Configuration Agent prepares an instantiated configuration file by substituting all the parameter values specified in the template with valid values for this device. The configuration server forwards the configuration file to the CNS web server for transmission to the routing device.
The CNS configuration agent accepts the configuration file from the CNS web server, performs XML parsing, checks syntax (optional), and loads the configuration file. The routing device reports the status of the configuration load as an event to which a network monitoring or workflow application can subscribe.
Incremental CNS Configuration
Once the network is up and running, new services can be added using the CNS configuration agent. Incremental (partial) configurations can be sent to routing devices. The actual configuration can be sent as an event payload by way of the event gateway (push operation) or as a signal event that triggers the device to initiate a pull operation.
The routing device can check the syntax of the configuration before applying it. If the syntax is correct, the routing device applies the incremental configuration and publishes an event that signals success to the configuration server. If the device fails to apply the incremental configuration, it publishes an event that indicates an error.
Once the routing device has applied the incremental configuration, it can write the configuration to NVRAM or wait until signaled to do so.
CNS IDs
The CNS identifier (ID) is a text string that is used exclusively with a particular CNS agent. The CNS ID is used by the CNS agent to identify itself to the server application with which it communicates. For example, the CNS configuration agent will include the configuration ID when communicating between the networking device and the configuration server. The configuration server uses the CNS configuration ID as a key to locate the attribute containing the Cisco IOS CLI configuration intended for the device that originated the configuration pull.
The network administrator must ensure a match between the CNS agent ID as defined on the routing device and the CNS agent ID contained in the directory attribute that corresponds to the configuration intended for the routing device. Within the routing device, the default value of the CNS agent ID is always set to the host name. If the host name changes, the CNS agent ID also changes. If the CNS agent ID is set using the CLI, any change will be followed by a message sent to syslog or an event message will be sent.
The CNS agent ID does not address security issues.
How to Configure CNS Agents
This section contains the following tasks:
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•
•
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•
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Deploying the CNS Router
Perform this task to manually install an initial CNS configuration.
Your remote router arrives from the factory with a bootstrap configuration. Upon initial power-on, the router automatically pulls a full initial configuration from the CNS configuration engine, although you can optionally arrange for this manually as well. After initial configuration, you can optionally arrange for periodic incremental (partial) configurations for synchronization purposes.
For more details on using the Cisco CNS configuration engine to automatically install the initial CNS configuration, refer to the Cisco CNS Configuration Engine Administrator's Guide at http://www.cisco.com/univercd/cc/td/doc/product/rtrmgmt/cns/ce/rel13/ag13/index.htm.
Initial CNS Configuration
Initial configuration of the remote router occurs automatically when the router is initialized on the network. Optionally, you can perform this configuration manually.
CNS assigns the remote router a unique IP address or host name. After resolving the IP address (using SLARP, ATM InARP, or PPP protocols), the system optionally uses DNS reverse lookup to assign a host name to the router and invokes the CNS agent to download the initial configuration from the CNS configuration engine.
SUMMARY STEPS
1.
2.
3.
4.
or
line-cli {modem-cmd | line-config-cmd}5.
6.
7.
8.
DETAILED STEPS
What to Do Next
If you do not need to configure CNS security features, proceed to the "Determining the CNS Agent ID" section.
Configuring CNS Security Features
Perform this optional task to configure CNS trusted servers.
CNS Trusted Servers
The cns trusted-server command can be used to specify a trusted server for an individual CNS agent or for all the CNS agents. To avoid security violations, you can build a list of trusted servers from which CNS agents can receive messages. An attempt to connect to a server not on the list will result in an error message being displayed.
Configure a CNS trusted server when a CNS agent will redirect its response to a server address that is not explicitly configured on the command line for the specific CNS agent. For example, the CNS exec agent may have one server configured but receive a message from the CNS event bus that overrides the configured server. The new server address has not been explicitly configured, so the new server address is not a trusted server. An error will be generated when the CNS exec agent tries to respond to this new server address unless the cns trusted-server command has been configured for the new server address.
SUMMARY STEPS
1.
2.
3.
DETAILED STEPS
Determining the CNS Agent ID
Perform this task to determine the CNS agent IDs. CNS agent IDs can be configured for the CNS event agent or CNS configuration agent. By default, the value of hostname is set as the CNS agent ID.
SUMMARY STEPS
1.
2.
3.
or
cns id {hardware-serial | hostname | string string} [event]4.
DETAILED STEPS
Enabling and Configuring the CNS Agents
Perform this task to enable and configure the various CNS agents.
CNS Event Agent Parameters
The CNS event agent command—cns event—has several parameters that can be configured. The failover-time keyword is useful if you have a backup CNS event gateway configured. If the CNS event agent is trying to connect to the gateway and it discovers that the route to the backup gateway is available before the route to the primary gateway, the seconds argument specifies how long the CNS event agent will continue to search for a route to the primary gateway before attempting to link to the backup gateway.
Unless you are using a bandwidth-constrained link, you should set a keepalive timeout and retry count. Doing so allows the management network to recover gracefully should a Cisco IE2100 configuration engine ever fail. Without the keepalive data, such a failure requires manual intervention on every device. The seconds value multiplied by the retry-count value determines the length of idle time before the CNS event agent will disconnect and attempt to reconnect to the gateway. We recommend a minimum retry-count value of 2.
If the optional source keyword is used, the source IP address might be a secondary IP address of a specific interface to allow a management network to run on top of a production network.
Note
SUMMARY STEPS
1.
2.
3.
4.
5.
6.
DETAILED STEPS
What to Do Next
If you do not need to configure any advanced CNS features, proceed to the "Monitoring and Verifying the CNS Agents" section.
Configuring Advanced CNS Features
Perform this task to configure more advanced CNS features. After the CNS agents are operational, you can configure some other features. You can enable the CNS inventory agent—that is, send an inventory of the router's line cards and modules to the CNS configuration engine—and enter CNS inventory mode.
Some other advanced features allow you to use the Software Developer's Toolkit (SDK) to specify how CNS notifications should be sent or how to access MIB information. Two encapsulation methods can be used: either nongranular (SNMP) encapsulation or granular (XML) encapsulation.
Incremental Configuration
Incremental or partial configuration allows the remote router to be incrementally configured after its initial configuration. You must perform these configurations manually through the CNS configuration engine. The registrar allows you to change the configuration templates, edit parameters, and submit the new configuration to the router without a software or hardware restart.
Prerequisites
This task assumes that CNS is operational and that the required CNS agents are configured.
SUMMARY STEPS
1.
2.
3.
4.
5.
6.
7.
8.
9.
DETAILED STEPS
Monitoring and Verifying the CNS Agents
Perform this optional task to display the status of the CNS event agent connection and to display a list of subjects about the CNS event agent connection.
SUMMARY STEPS
1.
2.
3.
DETAILED STEPS
Step 1
Enables privileged EXEC mode. Enter your password if prompted.
Router> enableStep 2
Use this command to display the status of the CNS event agent connection—such as whether it is connecting to the gateway, connected, or active—and to display the gateway used by the event agent and its IP address and port number.
Router# show cns event connectionsThe currently configured primary event gateway:hostname is 10.1.1.1.port number is 11011.Event-Id is Internal test1Keepalive setting:none.Connection status:Connection Established.The currently configured backup event gateway:none.The currently connected event gateway:hostname is 10.1.1.1.port number is 11011.Step 3
Use this command to display a list of subjects of the CNS event agent that are subscribed to by applications.
Router# show cns event subjectThe list of subjects subscribed by applications.cisco.cns.mibaccess:requestcisco.cns.config.loadcisco.cns.config.rebootcisco.cns.exec.cmd
Configuration Examples for CNS Agents
This section contains the following configuration examples:
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•
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Deploying the CNS Router: Example
The following example shows an initial configuration on a remote router. The host name of the remote router is the unique ID. The CNS configuration engine IP address is 172.28.129.22.
Router(config)# cns config connect-intf serial ping-interval 1 retries 1Router(config-cns-conn-if)# config-cli ip address negotiatedRouter(config-cns-conn-if)# config-cli encapsulation pppRouter(config-cns-conn-if)# config-cli ip directed-broadcastRouter(config-cns-conn-if)# config-cli no keepaliveRouter(config-cns-conn-if)# config-cli no shutdownRouter(config-cns-conn-if)# exitRouter(config)# hostname RemoteRouterRemoteRouter(config)# ip route 172.28.129.22 255.255.255.0 10.11.11.1RemoteRouter(config)# cns id Ethernet 0 ipaddressRemoteRouter(config)# cns config initial 10.1.1.1 no-persistRemoteRouter(config)# cns mib-access encapsulation xmlRemoteRouter(config)# cns notifications encapsulation xmlRemoteRouter(config)# cns inventoryRouter(cns_inv)# transport eventRouter(cns_inv)# exitConfiguring a Partial Configuration: Example
Incremental or partial configuration allows the remote router to be incrementally configured after its initial configuration. You must perform these configurations manually through the CNS configuration engine. The registrar allows you to change the configuration templates, edit parameters, and submit the new configuration to the router without a software or hardware restart.
The following example shows incremental (partial) configuration on a remote router. The CNS configuration engine IP address is 172.28.129.22, and the port number is 80.
Router(config)# cns config partial 172.28.129.22 80Enabling and Configuring CNS Agents: Example
The following example shows various CNS agents being enabled and configured starting with the configuration agent being enabled with the cns config partial command to configure an incremental (partial) configuration on a remote router. The CNS configuration engine IP address is 172.28.129.22, and the port number is 80. The CNS exec agent is enabled with an IP address of 172.28.129.23, and the CNS event agent is enabled with an IP address of 172.28.129.24. Until the CNS event agent is enabled, no other CNS agents are operational.
Router(config)# cns config partial 172.28.129.22 80Router(config)# cns exec 172.28.129.23 source 172.22.2.2Router(config)# cns event 172.28.129.24 source 172.22.2.1Router(config)# exitAdditional References
The following sections provide references related to CNS agents.
Related Documents
Standards
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.
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MIBs
RFCs
No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.
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Technical Assistance
Command Reference
This section documents new and modified commands only.
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announce config
To specify that an unsolicited configuration inventory is sent out by the CNS inventory agent at bootup, use the announce config command in CNS inventory configuration mode. To disable the sending of the configuration inventory, use the no form of this command.
announce config
no announce config
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
CNS inventory configuration
Command History
12.3(1)
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Use this command to limit inventory requests by the CNS inventory agent. When configured, the routing device details will be announced on the CNS event bus, but the routing device will not respond to any queries from the CNS event bus.
Examples
The following example shows how to configure the CNS inventory agent to send out an unsolicited configuration inventory one time only at bootup:
Router(config)# cns inventoryRouter(cns_inv)# announce configRelated Commands
cns inventory
Enables the CNS inventory agent and enters CNS inventory configuration mode.
clear cns config stats
To clear the statistics about the CNS configuration agent, use the clear cns config stats command in privileged EXEC mode.
clear cns config stats
Syntax Description
This command has no arguments or keywords.
Defaults
No statistics are cleared.
Command Modes
Privileged EXEC
Command History
12.3(1)
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
The clear cns config stats command clears all the statistics displayed by the show cns config stats command.
Examples
The following example shows how to clear all of the statistics for the CNS configuration agent:
Router# clear cns config statsRelated Commands
clear cns counters
To clear all CNS statistics, use the clear cns counters command in privileged EXEC mode.
clear cns counters
Syntax Description
This command has no arguments or keywords.
Defaults
No statistics are cleared.
Command Modes
Privileged EXEC
Command History
12.3(1)
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
The clear cns counters command clears all the statistics tracked and displayed by CNS agents.
Examples
The following example shows how to clear all of the statistics used by CNS:
Router# clear cns countersRelated Commands
clear cns event stats
To clear the statistics about the CNS event agent, use the clear cns event stats command in privileged EXEC mode.
clear cns event stats
Syntax Description
This command has no arguments or keywords.
Defaults
No statistics are cleared.
Command Modes
Privileged EXEC
Command History
12.3(1)
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
The clear cns event stats command clears all the statistics displayed by the show cns event stats command.
Examples
The following example shows how to clear all of the statistics for the CNS event agent:
Router# clear cns event statsRelated Commands
cns config cancel
To remove a partial Cisco Networking Services (CNS) configuration from the list of outstanding partial configurations, use the cns config cancel command in EXEC mode.
cns config cancel queue-id
Syntax Description
Defaults
No default behavior or values.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Incremental (partial) configurations take place in two steps:
1.
2.
Use the cns config cancel command in error scenarios where the second event message is not received and you need to remove the configuration from the list of outstanding configurations. Currently the maximum number of outstanding configurations is one.
Examples
The following example shows the process of checking the existing outstanding CNS configurations and cancelling the configuration with the queue-id of 1:
Router# show cns config outstandingThe outstanding configuration information:queue id identifier config-id1 identifierREAD config_idREADRouter# cns config cancel 1Router# show cns config outstandingThe outstanding configuration information:queue id identifier config-idRelated Commands
cns config connect-intf
To specify the interface for connecting to the Cisco Networking Services (CNS) configuration engine, use the cns config connect-intf command in global configuration mode. To disable this interface for the connection, use the no form of this command.
cns config connect-intf type number [ping-interval seconds] [retries number]
no cns config connect-intf type number
Syntax Description
Defaults
The ping interval defaults to 10 seconds.
The number of retries defaults to 5.Command Modes
Global configuration
Command History
12.2(8)T
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Use this command to connect to the CNS configuration engine using a specific type of interface. You must specify the interface type but need not specify the interface number; the router's bootstrap configuration finds the connecting interface, regardless of the slot in which the card resides or the modem dialout line for the connection, by trying different candidate interfaces or lines until it successfully pings the registrar.
Use this command to enter CSN Connect-interface configuration mode (config-cns-conn-if). Then use one of the following bootstrap-configuration commands to connect to the registrar for initial configuration:
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The config-cli command accepts the special directive character "&," which acts as a placeholder for the interface name. When the configuration is applied, the & is replaced with the interface name. Thus, for example, if we are able to connect using FastEthernet0/0, the command
config-cli ip route 0.0.0.0 0.0.0.0 &generates the command
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0.
Similarly, the command
config-virtual terminal line (vty) cns id & ipaddressgenerates the command
cns id FastEthernet0/0 ipaddressExamples
In the following example, the user connects to a configuration engine using the async interface and issues a number of commands:
Router(config)# cns config connect-intf AsyncRouter(config-cns-conn-if)# config-cli encapsulation pppRouter(config-cns-conn-if)# config-cli ip unnumbered FastEthernet0/0Router(config-cns-conn-if)# config-cli dialer rotary-group 0Router(config-cns-conn-if)# line-cli modem InOutRouter(config-cns-conn-if)# line-cli ...<other line commands>...Router(config-cns-conn-if)# exitThese commands result in the following configuration being applied:
line 65modem InOut...interface Async65encapsulation pppdialer in-banddialer rotary-group 0Related Commands
cns config initial
To enable the CNS configuration agent and initiate a download of the initial configuration, use the cns config initial command in global configuration mode. To remove an existing cns config initial command from the running configuration of the routing device, use the no form of this command.
cns config initial {host-name | ip-address} [encrypt] [port-number] [page page] [syntax-check] [no-persist] [source ip-address] [event] [inventory]
no cns config initial
Syntax Description
Defaults
The port number defaults to 80 with no encryption and 443 with encryption.
Default web page of the initial configuration is /cns/config.asp.Command Modes
Global configuration
Command History
Usage Guidelines
Use this command when a basic configuration—called a bootstrap configuration—is added to multiple routers before being deployed. When a router is initially powered (or each time a router is reloaded when the no-persist keyword is used) the cns config initial command will cause a configuration file—called an initial configuration—for the router to be downloaded from the configuration server. The initial configuration can be unique for each router.
When the configuration has been received by the router, each line of the configuration will be applied in the same order as it was received. If the Cisco IOS parser has an error with one of the lines of the configuration, then all the configuration up to this point will be applied to the router, but none of the configuration beyond the error will be applied. If an error occurs, the command will retry until it successfully completes. Once the configuration has successfully completed the cns config initial command will be removed from the running configuration. By default, NVRAM will be updated except when the no-persist keyword is configured.
When this command is used with the event keyword, a single message will be published on the event bus after the configuration is complete. The event bus will display one of the following status messages:
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Examples
The following example shows how to enable the CNS configuration agent and initiate an initial configuration:
Router# cns config initial 10.19.4.5 page /cns/config/first.aspRelated Commands
cns config notify
To notify CNS agents of configuration changes on Cisco IOS devices, use the cns config notify command in global configuration mode. To disable notifications, use the no form of this command.
cns config notify {all | diff} [interval minutes] [no_cns_events] [old-format]
no cns config notify {all | diff} [interval minutes] [no_cns_events] [old-format]
Syntax Description
Defaults
The interval defaults to 5 minutes.
Command Modes
Global configuration
Command History
Usage Guidelines
When the cns config notify command is enabled, commands entered in configuration mode are detected. If the all keyword is specified, the command is stored for future notification. If the diff keyword is specified, the command is stored for future notification if the software determines that the command will cause a configuration change. The diff keyword also allows the software to store information about the command including previous configuration states, source of the change (for example, a telnet user), and the time of configuration.
The stored information is formatted in XML and sent as part of a CNS config agent change notification event. A CNS config agent change notification event is sent to the CNS event bus when configuration mode is exited or no activity from that source has occurred for the configured interval time.
You must enable the CNS event agent using the cns event command before configuring this command. If the CNS event agent is not configured, the notification event will be queued and sent when the CNS event agent is enabled. If the CNS config notify queue is full, subsequent events are dropped and a "lost" CNS config change notification is sent when the CNS event agent is enabled.
Use the no_cns_events for applications that already record configuration changes sent to the routing device through the CNS event bus.
Use the old-format keyword to generate XML output—only the entered command and previous configuration state—that is compatible with the versions of this commands when the diff keyword was removed.
Examples
The following example detects configuration changes for all configuration commands:
Router(config)# cns config notify allRelated Commands
cns config partial
To start the CNS configuration agent and accept a partial configuration, use the cns config partial command in global configuration mode. To shut down the CNS partial configuration agent, use the no form of this command.
cns config partial {host-name | ip-address} [encrypt] [port-number] [source ip-address] [inventory]
no cns config partial
Syntax Description
Defaults
The port number defaults to 80 with no encryption and 443 with encryption.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to start the CNS partial configuration agent. You must enable the CNS event agent using the cns event command before configuring this command. The CNS event agent sends an event with the subject "cisco.mgmt.cns.config.load" to specify whether configuration data can be pushed to the CNS partial configuration agent or pulled from a configuration server by the CNS partial configuration agent.
In the push model, the event message delivers the configuration data to the partial configuration agent.
In the pull model, the event message triggers the partial configuration agent to pull the configuration data from the CNS configuration engine. The event message contains information about the CNS configuration engine, not the actual configuration data. The host name or IP address is the address of the CNS configuration engine from which the configuration is pulled. Use the cns trusted-server command to specify which CNS configuration engines can be used by the CNS partial configuration agent.
When the configuration has been received by the router, each line of the configuration will be applied in the same order as it was received. If the IOS parser has an error with one of the lines of the configuration, then all the configuration up to this point will be applied to the router, but none of the configuration beyond the error will be applied. If an error occurs, the command will retry until it successfully completes. In the pull mode, the command will not retry after an error. By default, NVRAM will be updated except when the no-persist keyword is configured.
A single message will be published on the CNS event bus after the partial configuration is complete. The CNS event bus will display one of the following status messages:
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•
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Examples
The following example shows how to configure the CNS partial configuration agent to accept events from the event gateway at 172.28.129.22. The CNS partial configuration agent will connect to the CNS configuration server at 172.28.129.22, port number 80. The CNS partial configuration agent requests are redirected to a configuration server at 172.28.129.40, port number 80.
Router(config)# cns event 172.28.129.22Router(config)# cns trusted-server config 172.28.129.40Router(config)# cns config partial 172.28.129.22Related Commands
cns config retrieve
To request the configuration of a routing device, use the cns config retrieve command in EXEC mode.
cns config retrieve {host-name | ip-address} [encrypt] [port-number] [page page] [overwrite-startup] [syntax-check] [no-persist] [source ip-address] [event] [inventory]
Syntax Description
Defaults
The port number defaults to 80 with no encryption and 443 with encryption.
Default web page of the initial configuration is /cns/config.asp.Command Modes
EXEC
Command History
Usage Guidelines
Use this command to request the configuration of a device from a configuration server. Use the cns trusted-server command to specify which configuration server can be used (trusted).
When the configuration has been received by the router, each line of the configuration will be applied in the same order as it was received. If the IOS parser has an error with one of the lines of the configuration, then all the configuration up to this point will be applied to the router, but none of the configuration beyond the error will be applied. If an error occurs, the command will not retry.
A single message will be published on the event bus after the partial configuration is complete. The event bus will display one of the following status messages:
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The cns config retrieve command can be used with Command Scheduler commands (for example, kron policy-list and cli commands) in environments where it is not practical to use the CNS event agent and the cns config partial command. Configured within the cli command, the cns config retrieve command can be used to poll the configuration server to detect configuration changes.
Examples
The following example shows how to request a configuration from a trusted server at 10.1.1.1:
Router(config)# cns trusted-server all 10.1.1.1Router(config)# cns config retrieve 10.1.1.1Related Commands
cns event
To configure the CNS event gateway, which provides CNS event services to Cisco IOS clients, use the cns event command in global configuration mode. To remove the specified event gateway from the gateway list, use the no form of this command.
cns event {host-name | ip-address} [encrypt] [port-number] [backup] [failover-time seconds] [keepalive seconds retry-count] [source ip-address]
no cns event {host-name | ip-address} [encrypt] [port-number] [backup] [failover-time seconds] [keepalive seconds retry-count] [source ip-address]
Syntax Description
Defaults
The event gateway port number default is 11011 with no encryption or 11012 with encryption.
The number of seconds to wait for a primary gateway route defaults to 3.
The system uses format 2.Command Modes
Global configuration
Command History
Usage Guidelines
The CNS event agent must be enabled before any of the other CNS agents are configured because the CNS event agent provides a transport connection to the CNS event bus for all other CNS agents. The other CNS agents use the connection to the CNS event bus to send and receive messages. The CNS event agent does not read or modify the messages.
The failover-time keyword is useful if you have a backup CNS event gateway configured. If the CNS event agent is trying to connect to the gateway and it discovers that the route to the backup is available before the route to the primary gateway, the seconds argument specifies how long the CNS event agent will continue to search for a route to the primary gateway before attempting to link to the backup gateway.
Unless you are using a bandwidth-constrained link, you should set a keepalive timeout and retry count. Doing so allows the management network to recover gracefully should a Cisco IE2100 configuration engine ever fail. Without the keepalive data, such a failure requires manual intervention on every device. The seconds multiplied by the retry-count determines the length of idle time before the CNS event agent will disconnect and attempt to reconnect to the gateway. We recommend a minimum retry-count of two.
If the optional source keyword is used, the source IP address might be a secondary IP address of a specific interface to allow a management network to run on top of a production network.
Examples
The following example shows how to set the address of the primary CNS event gateway to the configuration engine software running on IP address 10.1.2.3, port 11011, with a keepalive of 60 seconds and a retry count of 5:
Router(config)# cns event 10.1.2.3 11011 keepalive 60 5Related Commands
cns id
Sets the unique event ID or config ID router identifier.
show cns event status
Displays status information about the CNS event agent.
cns exec
To enable and configure the CNS exec agent, which provides CNS exec services to Cisco IOS clients, use the cns exec command in global configuration mode. To disable the use of CNS exec agent services, use the no form of this command.
cns exec [host-name | ip-address] [encrypt [enc-port-number]] [port-number] [source ip-address]
no cns exec [host-name | ip-address] [encrypt [enc-port-number]] [port-number] [source ip-address]
Syntax Description
Defaults
The default exec server port number is 80.
The default encrypted exec server port number is 443.Command Modes
Global configuration
Command History
12.3(1)
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
The CNS exec agent allows a remote application to execute an EXEC mode command-line interface (CLI) command on a Cisco IOS device by sending an event message containing the command. A restricted set of EXEC CLI commands—show commands—are supported.
In previous Cisco IOS Releases the CNS exec agent was enabled when the CNS configuration agent was enabled through the cns config partial command.
Examples
The following example shows how to enable the CNS exec agent with an IP address of 10.1.2.3 for the exec agent server, a port number of 93, and a source IP address of 172.17.2.2:
Router(config)# cns exec 10.1.2.3 93 source 172.17.2.2Related Commands
cns event
Enables and configures CNS event agent services.
show cns event subject
Displays a list of CNS event agent subjects that are subscribed to by applications.
cns id
To set the unique event ID, or config ID Cisco IOS device identifier used by CNS services, use the cns id command in global configuration mode. To set the identifier to the host name of the Cisco IOS device, use the no form of this command.
If ID Choice Is IP Address or MAC Address
cns id type number {dns-reverse | ipaddress | mac-address} [event]
no cns id type number {dns-reverse | ipaddress | mac-address} [event]
If ID Choice Is Anything Else
cns id {hardware-serial | hostname | string string} [event]
no cns id {hardware-serial | hostname | string string} [event]
Syntax Description
Defaults
The system defaults to the host name of the Cisco IOS device as the unique ID.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to set the unique ID to the CNS configuration agent, which then pulls the initial configuration template to the Cisco IOS device during bootup.
You can set one or both IDs: the config ID value for CNS configuration services, and the event ID value for CNS event services. To set all values, use the command twice.
To set the CNS event ID to the host name of the Cisco IOS device, use the no form of this command with the event keyword. To set the CNS config ID to the host name of the Cisco IOS device, use the no form of this command without the event keyword.
Examples
The following example shows how to pass the host name of the Cisco IOS device as the config ID value:
Router(config)# cns id hostnameThe following example shows how to pass the hardware serial number of the Cisco IOS device as the event ID value:
Router(config)# cns id hardware-serial eventRelated Commands
cns event
Enables the CNS event gateway, which provides CNS event services to Cisco IOS clients.
cns inventory
To enable the CNS inventory agent—that is, to send an inventory of the router's line cards and modules to the CNS configuration engine—and enter CNS inventory mode, use the cns inventory command in global configuration mode. To disable the CNS inventory agent, use the no form of this command.
cns inventory
no cns inventory
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Global configuration
Command History
12.2(8)T
This command was introduced.
12.3(1)
The config, event, and notify oir keywords were removed.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Use this command with the announce config and transport event CNS inventory configuration mode commands to specify when to notify the CNS configuration engine of changes to the router's port-adaptor and interface inventory. A transport must be specified in CNS inventory configuration mode before any of the CNS inventory commands are executed.
Examples
The following example shows how to enable the CNS inventory agent and enter CNS inventory configuration mode:
Router(config)# cns inventoryRouter(cns_inv)#Related Commands
cns mib-access encapsulation
To specify whether CNS should use nongranular (SNMP) or granular (XML) encapsulation to access MIBs, use the cns mib-access encapsulation command in global configuration mode. To disable the currently specified encapsulation, use the no form of this command.
cns mib-access encapsulation {snmp | xml [size bytes]}
no cns mib-access encapsulation {snmp | xml}
Syntax Description
Defaults
For XML encapsulation, a maximum size of 3072 bytes.
Command Modes
Global configuration
Command History
12.2(8)T
This command was introduced on Cisco 2600 series and Cisco 3600 series routers.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Examples
The following example specifies that XML be used to access MIBs:
Router(config)# cns mib-access encapsulation xmlRelated Commands
cns notifications encapsulation
Specifies whether CNS notifications should be sent using nongranular (SNMP) or granular (XML) encapsulation.
cns notifications encapsulation
To specify whether CNS notifications should be sent using nongranular (SNMP) or granular (XML) encapsulation, use the cns notifications encapsulation command in global configuration mode. To disable the currently specified encapsulation, use the no form of this command.
cns notifications encapsulation {snmp | xml}
no cns notifications encapsulation {snmp | xml}
Syntax Description
snmp
Uses nongranular (SNMP) encapsulation to send notifications.
xml
Uses granular (XML) encapsulation to send notifications.
Defaults
This command is disabled.
Command Modes
Global configuration
Command History
12.2(8)T
This command was introduced on Cisco 2600 series and Cisco 3600 series routers.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Examples
The following example shows how to specify that granular notifications should be sent:
Router(config)# cns notifications encapsulation xmlRelated Commands
cns mib-access encapsulation
Specifies whether CNS should use granular (XML) or nongranular (SNMP) encapsulation to access MIBs.
cns trusted-server
To specify a trusted server for CNS agents, use the cns trusted-server command in global configuration mode. To disable the use of a trusted server for a CNS agent, use the no form of this command.
cns trusted-server {all-agents | config | event | exec} {host-name | ip-address}
no cns trusted-server {all-agents | config | event | exec}
Syntax Description
Defaults
all-agents
Command Modes
Global configuration
Command History
12.3(1)
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Use the cns trusted-server command to specify a trusted server for an individual CNS agent or all the CNS agents. In previous Cisco IOS Releases CNS agents could connect to any server and this could expose the system to security violations. An attempt to connect to a server not on the list will result in an error message being displayed. For backwards compatibility the configuration of a server address using the configuration command-line interface (CLI) for a CNS agent will result in an implicit trust of the server. The implicit trusted server commands apply only to commands in configuration mode, not EXEC mode commands.
Use this command when a CNS agent will redirect its response to a server address that is not explicitly configured on the command line for the specific CNS agent. For example, the CNS exec agent may have one server configured but receive a message from the CNS Event Bus that overrides the configured server. The new server address has not been explicitly configured so the new server address is not a trusted server. An error will be generated when the CNS exec agent tries to respond to this new server address unless the cns trusted-server command has been configured for the new server address.
Examples
The following example shows how to configure server 10.19.2.5 as a trusted server for the CNS event agent:
Router# cns trusted-server event 10.19.2.5The following example shows how to configure server 10.2.2.8 as an implicit trusted server for the CNS image agent:
Router# cns image server 10.2.2.8 status 10.2.2.8Related Commands
cns config
Configures CNS configuration agent services.
cns event
Enables and configures CNS event agent services.
cns image
Configures CNS image agent services.
config-cli
To connect to the CNS configuration engine using a specific type of interface, use the config-cli command in CNS Connect-interface configuration mode.
config-cli {type [number] | interface-config-cmd}
Syntax Description
Defaults
No default behavior or values.
Command Modes
CNS Connect-interface configuration
Command History
12.2(8)T
This command was introduced on Cisco 2600 series and Cisco 3600 series routers.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Begin by using the cns config connect-intf command to enter CNS Connect-interface configuration (config-cns-conn-if) submode. Then use either this or its companion CNS bootstrap-configuration command to connect to the CNS configuration engine for initial configuration:
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Immediately after either of the commands, enter additional configuration commands as appropriate.
Examples
The following example enters CNS Connect-interface Configuration mode, connects to a configuration engine using an asynchronous interface, and issues a number of commands:
Router(config)# cns config connect-intf AsyncRouter(config-cns-conn-if)# config-cli encapsulation pppRouter(config-cns-conn-if)# config-cli ip unnumbered FastEthernet0/0Router(config-cns-conn-if)# config-cli dialer rotary-group 0Router(config-cns-conn-if)# line-cli modem InOutRouter(config-cns-conn-if)# line-cli ...<other line commands>...Router(config-cns-conn-if)# exitThese commands apply the following configuration:
line 65modem InOut...interface Async65encapsulation pppdialer in-banddialer rotary-group 0Related Commands
cns config connect-intf
Specifies the interface for connecting to the CNS configuration engine.
line-cli
Connects to the CNS configuration engine using a modem dialup line.
debug cns exec
To display debugging messages about CNS exec agent services, use the debug cns exec command in privileged EXEC mode. To disable debugging output, use the no or undebug form of this command.
debug cns exec {agent | all | decode | messages}
no debug cns exec {agent | all | decode | messages}
undebug cns exec {agent | all | decode | messages}
Syntax Description
Defaults
Debugging output is disabled.
Command Modes
Privileged EXEC
Command History
12.3(1)
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Use the debug cns exec command to troubleshoot CNS exec agent services.
Examples
The following example shows a debugging message for the CNS exec agent when a response has been posted to HTTP:
Router# debug cns exec agent4d20h: CNS exec agent: response postedRelated Commands
line-cli
To connect to the CNS configuration engine using a modem dialup line, use the line-cli command in CNS Connect-interface configuration mode.
line-cli {modem-cmd | line-config-cmd}
Syntax Description
Defaults
No default behavior or values.
Command Modes
CNS Connect-interface configuration
Command History
12.2(8)T
This command was introduced on Cisco 2600 series and Cisco 3600 series routers.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Use this command to connect to the CNS configuration engine using a modem dialout line. The bootstrap configuration on the router finds the connecting interface, regardless of the slot in which the card resides or the modem dialout line for the connection, by trying different candidate interfaces or lines until it successfully pings the registrar.
Enter this command in CNS connect-interface-config (config-cns-conn-if) submode. Then use one of the following bootstrap-configuration commands to connect to the registrar for initial configuration:
•
•
The config-cli command accepts the special directive character "&," which acts as a placeholder for the interface name. When the configuration is applied, the & is replaced with the interface name. Thus, for example, if we are able to connect using FastEthernet0/0, the following is the case:
•
generates the command config ip route 0.0.0.0 0.0.0.0 FastEthernet0/0.•
generates the command cns id FastEthernet0/0 ipaddressExamples
The following example enters connect-interface-config if submode, connects to a configuration engine using an asynchronous interface, and issues a number of commands:
Router(config)# cns config connect-intf AsyncRouter(config-cns-conn-if)# config-cli encapsulation pppRouter(config-cns-conn-if)# config-cli ip unnumbered FastEthernet0/0Router(config-cns-conn-if)# config-cli dialer rotart-group 0Router(config-cns-conn-if)# line-cli modem InOutRouter(config-cns-conn-if)# line-cli ...<other line commands>...Router(config-cns-conn-if)# exitThese commands apply the following configuration:
line 65modem InOut...interface Async65encapsulation pppdialer in-banddialer rotary-group 0Related Commands
logging cns-events
To enable XML-formatted system event message logging to be sent trough the CNS event bus, use the logging cns-events command in global configuration mode. To disable the ability to send system logging event messages through the CNS event bus, use the no form of this command.
logging cns-events [severity-level]
no logging cns-events
Syntax Description
Defaults
Level 7: debugging
Command Modes
Global configuration
Command History
12.2(2)T
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Before you configure this command you must enable the CNS event agent with the cns event command because the CNS event agent sends out the CNS event logging messages. The generation of many CNS event logging messages can negatively impact the publishing time of standard CNS event messages that must be sent to the network.
If the debug cns event command is active when the logging cns-events command is configured, the logging of CNS events is disabled.
Examples
In the following example, the user enables XML-formatted CNS system error message logging to the CNS event bus for messages at levels 0 through 4:
Router(config)# logging cns-events 4Related Commands
cns event
Configures CNS event gateway, which provides CNS event services to Cisco IOS clients.
debug cns event
Displays CNS event agent debugging messages.
show cns config stats
To display statistics about the CNS configuration agent, use the show cns config stats command in privileged EXEC mode.
show cns config stats
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
This command displays the following statistics on the CNS configuration agent:
•
•
•
•
•
•
•
Examples
The following is sample output from the show cns config stats command:
Router# show cns config stats6 configuration requests received.4 configurations completed.1 configurations failed.1 configurations pending.0 configurations cancelled.The time of last received configuration is *May 5 2003 10:42:15 UTC.Initial Config received *May 5 2003 10:45:15 UTC.Related Commands
show cns event connections
To display the status of the CNS event agent connection, use the show cns event connections command in privileged EXEC mode.
show cns event connections
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
12.2(8)T
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Use the show cns event connections command to display the status of the event agent connection—such as whether it is connecting to the gateway, connected, or active—and to display the gateway used by the event agent and its IP address and port number.
Examples
The following example displays the IP address and port number of the primary and backup gateways:
Router# show cns event connectionsThe currently configured primary event gateway:hostname is 10.1.1.1.port number is 11011.Event-Id is Internal test1Keepalive setting:none.Connection status:Connection Established.The currently configured backup event gateway:none.The currently connected event gateway:hostname is 10.1.1.1.port number is 11011.Related Commands
show cns event stats
Displays statistics about the CNS event agent connection.
show cns event subject
Displays a list of subjects about the CNS event agent connection.
show cns event stats
To display statistics about the CNS event agent connection, use the show cns event stats command in privileged EXEC mode.
show cns event stats
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Use this command to display the following statistics for the CNS event agent:
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•
•
•
•
•
•
•
•
•
Examples
The following example displays statistics for the CNS event agent:
Router# show cns event stats0 events received.1 events sent.0 events not processed.0 events in the queue.0 events sent to other IOS applications.Event agent stats last cleared at Apr 4 2003 00:55:25 UTCNo events received since stats clearedThe time stamp of the last received event is *Mar 30 2003 11:04:08 UTCThe time stamp of the last sent event is *Apr 11 2003 22:21:23 UTC3 applications are using the event agent.0 subjects subscribed.1 subjects produced.0 subjects replied.Related Commands
show cns event subject
To display a list of subjects about the CNS event agent connection, use the show cns event subject command in privileged EXEC mode.
show cns event subject [name]
Syntax Description
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Use the show cns event subject command to display a list of subjects of the event agent that are subscribed to by applications.
Examples
The following example displays the IP address and port number of the primary and backup gateways:
Router# show cns event subjectThe list of subjects subscribed by applications.cisco.cns.mibaccess:requestcisco.cns.config.loadcisco.cns.config.rebootcisco.cns.exec.cmdRelated Commands
show cns event connections
Displays the status of the CNS event agent connection.
show cns event stats
Displays statistics about the CNS event agent connection.
transport event
To specify that inventory events are sent out by the CNS inventory agent, use the transport event command in CNS inventory configuration mode. To disable the transport of inventory events, use the no form of this command.
transport event
no transport event
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
CNS inventory configuration
Command History
12.3(1)
This command was introduced.
12.2(25)S
This command was integrated into Cisco IOS Release 12.2(25)S.
Usage Guidelines
Use this command to send out inventory requests with each CNS inventory agent message. When configured, the routing device will respond to queries from the CNS event bus. Online insertion and removal (OIR) events on the routing device will be reported to the CNS event bus.
Examples
The following example shows how to enable the CNS inventory agent and configure it to send out inventory events:
Router(config)# cns inventoryRouter(cns_inv)# transport eventRelated Commands
cns inventory
Enables the CNS inventory agent and enters CNS inventory configuration mode.
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