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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 5 Configuring IE2100 CNS Agents
Unders tanding IE2100 Series Configura tion Registrar Softw are

DeviceID

Each configured switch participating on the event bus has a un ique deviceID, whi ch is an alogous to t he
switch source ad dress so that the switch can be targete d as a specific destination on the b us. All switches
configured with the cns con fig parti al global configuration command must access the event bus.
Theref ore, the deviceID, as origina ted on the swi tch, mu st match the devi ceID of th e corres pondi ng
switch definition in the Configuration Registrar.
The origin of the deviceID is defined by the Cisc o IOS host nam e of the switch. However, the deviceID
variable and its usage reside within the event gateway, which is adjacent to the switch.
The logical Cisco IOS termination point on the event bus is embedded in the event gateway, which in
turn functions as a proxy on behalf of the switch. The event gateway represents the switch and its
corresponding deviceID to the event bus.
The switc h decla res its host na me to the event gateway immediate ly after t he succe ssful conne ctio n to
the event gateway. The event gateway couples the deviceID va lue to the Cisco IOS host n ame eac h time
this connection is established. The event gateway caches this deviceID value for the duration of its
connection to the switch.

Host Name and DeviceID

The deviceID is fix ed at the time of the connection to the event gate way and does not change even when
the swi tch ho st name is re configured .
When ch an ging the switch ho st n am e o n the s witc h, the only wa y t o r ef re s h the deviceID is to b re ak th e
connection between the switch and the event gatewa y. Enter the no cns event global c onfigura tion
command followed by the cns event glob al co nfiguration c omman d.
When the connection is re-established, the switch sends its modified host name to the event gatew ay. The
event gateway redefines the dev iceID to the new value.
Caution When using the Con figuration R egistrar user inter face, yo u m ust first set the deviceID field to the host
name v a lue th at th e swit ch acq uires after–not before–you use the cns config ini tial global configuration
command a t th e sw itch. Ot herw ise, su bseque nt cns config partial global configuration command
operati ons malfunc tion.

Using Host Name, DeviceID, and ConfigID

In sta ndal one m ode, wh en a host name value is se t fo r a swit ch, the con figurat ion ser ver us es t he ho st
name as the deviceID when an event is sent on h ost name. I f the h os t name has not b ee n set, th e event is
sent on the cn= < value> of the device.
In server mode, the host name is not used. In this mode, the unique deviceID attribute is always used for
sending an event on the bus. If thi s att ribute is no t set , you c annot updat e t he swit ch.
These and other associated attributes (tag value pairs) are set when you run Setup on the Config uration
Registrar.
Note For more information about running the setup program on the Configuration Registrar , refer to the Cisco
Intelligenc e Engine 2100 Series Configuration Registrar Manual.