Managing BCM agent connection behavior

From the Global Settings > System Variables > Connection Management tab, you can define the default settings for how connections to devices are managed.

This topic describes the settings that define the connection between a BCM agent and the BCM master database.

Defining the agent connection settings

Modifying any of these values affects the entire operation of BMC Client Management. It is therefore strongly recommended to make the definition of these settings part of the initial planning before any deployment to your network. If, however, you execute any changes later on, you must restart the agent service on the master server before launching a network rollout process.

Which attributes are used to generate GUIDs

The attributes used to generate GUID are defined on the Global Settings > System Variables > Connection Management tab.

Use the serial number of the main logical volume disks to uniquely identify device
Use host ID to uniquely identify device
Use the domain name to uniquely identify device
Use the MAC address to uniquely identify device
Use the NetBIOS name to uniquely identify device

How BCM generates GUIDs for devices

For eliminating duplicate Global Unique Identifiers (GUIDs) associated to devices, BCM has enhanced its GUID generation mechanism. The new mechanism uses all the attributes to generate a GUID. Therefore, any change in the attribute values does not cause BCM to consider the device as a new device. BCM performs an attribute match in the master database. If an attribute match is found, the registered GUID for the device is retained in the database. This ensures that GUIDs are not duplicated in the master database and there are no communication issues between the master database and the agents.

The only case where the mechanism changes is when an agent needs to be re-installed on a device.

How is GUID generated when a BCM agent is re-installed on devices

When a BCM admin rolls out an agent on a device for the first time, the agent generates a new GUID for the device. For some reason, if the agent needs to be re-installed on the same device, the agent regenerates a GUID for that device. This creates multiple GUIDs for the same device.

BCM does the following to ensure GUID uniqueness:

Checks whether there are two GUIDs
Finds a match between the new GUID values and the existing GUID values in the BCM database
If BCM finds GUID values that match, it replaces the existing GUID in the BCM database with the new GUID
Records the new GUID value in the BCM database

Connection Parameters

From BMC Client Management 12.6 onwards, BMC Client Management uses all the attributes of a device to generate GUIDs, irrespective of whether an attribute is enabled or not. These system variables are used to uniquely identify a device in the master database.

Parameter	Description
Use the domain name to uniquely identify device	Check this box if you want to use the host name to uniquely identify the device. For most companies this attribute would be the most recommended, because in their networks the host names of the clients are in almost all cases unique. If the names are not unique but this option is nevertheless to be used for identification, make sure to select the Complete Name option for the Client Identification Type , otherwise one or more of the devices with the same name cannot be recognized as different clients if you have not activated the following option Allow Duplicate Device Names .
Use host ID to uniquely identify device	Check this box if you want to use the host ID to uniquely identify the device. Do not use this option if you do not have a system with exclusively new devices, because this attribute is only unique if the clients have WMI. If the clients do not have WMI the value returned is empty.
Use the NetBIOS name to uniquely identify device	Check this box if you want to use the NetBIOS name to uniquely identify the device.
Use the MAC address to uniquely identify device	Check this box if you want to use the MAC address to uniquely identify the device. Do not use this option if you switch network cards between devices or have devices with several network cards.
Use the serial number of the main logical volume disk to uniquely identify device	Check this box if you want to use the serial number of the main logical to uniquely identify the device. Do not use this attribute if you use ghosts in your network.
Automatically Update Device Name	Check this box if the device name is to be automatically updated when it is changed. By default, the box is enabled. If this functionality is disabled, only the NetBIOS name will be updated to the device's new name if it is changed. This functionality should only be used in environments in which a lot of name changing takes place such as through regular ghosting, to ensure consistency in device tracking and identification as well as reliable queries.
Case of Device Name	Specifies if the names of the devices are to be case sensitive. By default this option is set to Indifferent , indicating that the name will be entered into the database in exactly the way it was entered by the user. If for example, the option Upper Case is selected and the name is entered in a mixture of upper and lower case letters the name will be automatically stored in the database with upper case letters only, and vice versa for the option Lower Case .
Client Identification Type	Defines the identification type used when a new client is installed. If the value entered exists already in the database, the client is regarded as an already existing device and will not be added again. The possible types of identification are the following: Complete Name , Host Name , IP Address and NetBIOS Name . If the network names of your clients are not unique and you are using the host name to uniquely identify the devices, this variable must obligatorily be set to Complete Name . Otherwise one or more of the devices might not be recognized as different clients. Also, if you are using a super master architecture this value is strongly recommended to be used, to avoid cases in which two devices could have the same short name in two different sites. In such a case the super master would regard these two devices as one, therefore only store one device and each new upload from one or the other site master will overwrite the previous data in the database.
Lost Client after Delay of	Defines the time interval which can elapse after the last update from a client agent before it is declared as lost. The default value is *24 (hours)* .
Unit for Lost Client	Defines the unit for the value defined in the preceding field. Possible values are *Seconds* , *Minutes* , *Hours* , *Days* and *Weeks* .
Lost Relay after Delay of	Defines the time interval which can elapse after the last update from a relay agent before it is declared as lost. The default value is *24 (hours)* .
Unit for Lost Relay	Defines the unit for the value defined in the preceding field. Possible values are *Seconds* , *Minutes* , *Hours* , *Days* and *Weeks* .
Allow Duplicate Device Names	Check this box if devices with the same name and IP address are considered as the same device or as different devices. If this option is deactivated, that is, set to No, a second device with the same name and IP address will be considered to be the same device as the first one and thus will update the old data with its new data. If the option is activated, the second device will be created as a new device with the same name as the first suffixed by a number, that is, scotty for the first device, scotty (1) for the second.
Automatic Agent Version Upgrade	Check this box to ensure that the environment's agent are automatically upgraded once the master is upgraded to a new version.
List of banned GUIDs	Allows the administrator to provide a comma separated list of prohibited GUIDs. The Identity module on the devices regulary checks if this list has changed. When a device generates its GUID it verifies that the generated GUID is not part of the list. If this should be the case the GUID generation is cancelled.