Controlling NetMRI with Device Groups

Basic device groups limit their processing options to a minimum. Basic device groups do not contribute to NetMRI Network Scorecard calculations and significantly reduce back-end processing. You can define group membership criteria. For more information, see Understanding Device Group Membership Criteria.

Extended device groups provide a substantial collection of settings to determine how an extended device group processes its information. Along with defining group membership criteria, a number of options help determine the level and types of processing performed by an extended device group:

• Include non-network devices: Enables collecting end-host network segments into a basic device group to avoid expanding system processing cycles on network devices that do not require them.
• Rank: For more information, see Ranking Device Groups.
• Polling Frequency: Allows you to modify the default polling frequency for all devices or for specific device groups. For more information, see Creating Extended Device Groups.
• Switch Port data collection: Enable this only for device groups with L2/L3 Ethernet switching devices as members. This allows you to enforce custom periodic or scheduled polling settings for specific groups. For more information, see Device Groups and Switch Port Management.
• Collect performance and environmental data: Enable or disable device performance and environmental information. For more information, see Changing Performance Data Collection Settings.
• Probe for open ports: Allows NetMRI to probe for open TCP/UDP ports on member devices.
• Identify device using fingerprinting: For more information, see Defining Group Data Collection Settings.
• Probe for NetBIOS name: For more information, see Defining Group Data Collection Settings.
• Analyze for Issues: For more information, see Evaluating Issues in NetMRI and Viewing Device Issues, Configurations, and Changes.
• Test for default credentials: Allows NetMRI to test all devices in the group for the presence of vendor default SNMP credentials, which are a potential element for security breaches, but are also used for assistance in collecting device configurations. Credential default testing is also a compliance measure.
• Collect config files: For more information, see beginning with Configuration Management.
• Regard configurations as 'Locked': Disallows editing of any collection configuration files for members of the device group.
• Allow script execution: Allows the execution of Perl and CCS scripts on group member devices.
• Enable Discovery Blackout: Define time periods when NetMRI will not communicate with devices or networks for discovery.
• Enable Change Blackout: Define blackouts for CLI interaction, scheduled or run-now job executions, Telnet/SSH proxy, and port control UI features for all devices in the group. For more information, see Defining Blackout Periods.

All settings are further described in the topic Creating Device Groups.

You can convert basic device groups to extended device groups, and also the reverse, at any time.

Some types of network devices warrant more processing by NetMRI, such as the collection of performance and environmental data, open ports probing, NetBIOS name probing, collecting of configuration files, analyzing for issues, and other device processing features. Some device types can be quickly excluded from complex processing tasks by simply assigning them to a basic device group. Many end-host networks may fall into this category.