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Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
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Chapter 4 Configuring Cisco IOS CNS Agents
Configuring Cisco IOS Agents
Upgrading Devices with Cisco IOS Image Agent
Administrators maintaining large networks of Cisco IOS devices need an automated mechanism to load
image files onto large numbers of remote devices. Existing network management applications are useful
to determine which images to run and how to manage images received from the Cisco online software
center. Other image distribution solutions do not scale to cover thousands of devices and cannot
distribute images to devices behind a firewall. The CNS image agent enables the managed device to
initiate a network connection and request an image download allowing devices behind firewalls to access
the image server.
You can use image agent to download one or more devices. The switches must have the image agent
running on them.

Prerequisites for the CNS Image Agent

Confirm these prerequisites before upgrading one or more devices with image agent:
• Determine where to store the Cisco IOS images on a file server to make the image available to the
other networking devices. If the CNS Event Bus is to be used to store and distribute the images, the
CNS event agent must be configured.
• Set up a file server to enable the networking devices to download the new images using the HTTPS
protocol.
• Determine how to handle error messages generated by image agent operations. Error messages can
be sent to the CNS Event Bus or an HTTP or HTTPS URL.

Restrictions for the CNS Image Agent

During automated image loading operations you must try to prevent the Cisco IOS device from losing
connectivity with the file server that is providing the image. Image reloading is subject to memory issues
and connection issues. Boot options must also be configured to allow the Cisco IOS device to boot
another image if the first image reload fails.
These other restrictions apply to the image agent running on a the switch:
• You can only download the tar image file. Downloading the bin image file is not supported.
• Only the immediate download option is supported. You cannot schedule a download to occur at a
specified date and time.
• The Destination field in the Associate Image with Device window is not supported.
For more details, see your CNS IE2100 documentation and see the “File Management” section of the
Cisco IOS Configuration Fundamentals Configuration Guide, Release 12.2.
Beginning in privileged EXEC mode, follow these steps to initiate the image agent to check for a new
image and upgrade a device:
Command Purpose
Step 1 configure terminal Enter global configuration mode
Step 2 ip host {ip-address} {hostname} Enter the IP address and the hostname of the event
gateway.
Step 3 cns trusted-server all-agents {hostname} Specify a trusted server for CNS agent.
Step 4 no cns aaa enable cns event {ip-address} {port number}Disable AAA authentication on the event gateway.