Cisco Catalyst 2950 - CNS Event Service; Namespace Mapper; What You Should Know about Configid, Deviceid, and Host Name; Configid

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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
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Chapter 5 Configuring IE2100 CNS Agents
Understanding IE2100 Series Configuration Registrar Software
CNS Event Service
The Configuration Registrar uses the CNS Event Service for receipt and generation of configuration
events. The CNS event agent resides on the switch and facilitates the communication between the switch
and the event gateway on the Configuration Registrar.
The CNS Event Service is a highly capable publish-and-subscribe communication method. The CNS
Event Service uses subject-based addressing to send messages to their destinations. Subject-based
addressing conventions define a simple, uniform namespace for messages and their destinations.
NameSpace Mapper
The Configuration Registrar includes the NameSpace Mapper (NSM) that provides a lookup service for
managing logical groups of devices based on application, device ID or group ID, and event.
Cisco IOS devices recognize only event subject-names that match those configured in Cisco IOS
software; for example, cisco.cns.config.load. You can use the namespace mapping service to designate
events by using any desired naming convention. When you have populated your data store with your
subject names, NSM resolves your event subject-name strings to those known by Cisco IOS.
For a subscriber, when given a unique device ID and event, the namespace mapping service returns a set
of events to which to subscribe. Similarly, for a publisher, when given a unique group ID, device ID, and
event, the mapping service returns a set of events on which to publish.
What You Should Know About ConfigID, DeviceID, and Host Name
The Configuration Registrar assumes that a unique identifier is associated with each configured switch.
This unique identifier can take on multiple synonyms, where each synonym is unique within a particular
namespace. The event service uses namespace content for subject-based addressing of messages.
The Configuration Registrar intersects two namespaces, one for the event bus and the other for the
configuration server. Within the scope of the configuration server namespace, the term configID is the
unique identifier for a device. Within the scope of the event bus namespace, the term deviceID is the
CNS unique identifier for a device.
Because the Configuration Registrar uses both the event bus and the configuration server to provide
configurations to devices, you must define both configID and deviceID for each configured switch.
Within the scope of a single instance of the configuration server, no two configured switches can share
the same value for configID. Within the scope of a single instance of the event bus, no two configured
switches can share the same value for deviceID.
ConfigID
Each configured switch has a unique configID, which serves as the key into the Configuration Registrar
directory for the corresponding set of switch CLI attributes. The configID defined on the switch must
match the configID for the corresponding switch definition on the Configuration Registrar.
The configID is fixed at boot time and cannot be changed until reboot, even when the switch host name
is reconfigured.