83
Configuring Cisco IOS Configuration Engine
Information About Configuring Cisco IOS Configuration Engine
Hostname and DeviceID Interaction
The DeviceID is fixed at the time of the connection to the event gateway and does not change even when the switch
hostname is reconfigured.
When changing the switch hostname on the switch, the only way to refresh the DeviceID is to break the connection
between the switch and the event gateway. Enter the no cns event global configuration command followed by the cns
event global configuration command.
When the connection is reestablished, the switch sends its modified hostname to the event gateway. The event gateway
redefines the DeviceID to the new value.
Using Hostname, DeviceID, and ConfigID
In standalone mode, when a hostname value is set for a switch, the configuration server uses the hostname as the
DeviceID when an event is sent on hostname. If the hostname has not been set, the event is sent on the cn=<value> of
the device.
In server mode, the hostname is not used. In this mode, the unique DeviceID attribute is always used for sending an event
on the bus. If this attribute is not set, you cannot update the switch.
These and other associated attributes (tag value pairs) are set when you run Setup on Configuration Engine.
Cisco IOS Agents
The CNS event agent feature allows the switch to publish and subscribe to events on the event bus and works with the
Cisco IOS agent.
Initial Configuration
When the switch first comes up, it attempts to get an IP address by broadcasting a DHCP request on the network.
Assuming there is no DHCP server on the subnet, the distribution switch acts as a DHCP relay agent and forwards the
request to the DHCP server. Upon receiving the request, the DHCP server assigns an IP address to the new switch and
includes the TFTP server IP address, the path to the bootstrap configuration file, and the default gateway IP address in
a unicast reply to the DHCP relay agent. The DHCP relay agent forwards the reply to the switch.
The switch automatically configures the assigned IP address on interface VLAN 1 (the default) and downloads the
bootstrap configuration file from the TFTP server. Upon successful download of the bootstrap configuration file, the
switch loads the file in its running configuration.
The Cisco IOS agents initiate communication with Configuration Engine by using the appropriate ConfigID and EventID.
Configuration Engine maps the ConfigID to a template and downloads the full configuration file to the switch.
Figure 6 on page 84 shows a sample network configuration for retrieving the initial bootstrap configuration file by using
DHCP-based autoconfiguration.
To Next Page
Loading...
Need help?
General
