How to delete model connections and prevent rediscovery in DX Spectrum

Products

• Network Observability
• Spectrum

Issue/Introduction

Need to remove connections (links) between specific models to disable alarm suppression and fault isolation functionality for those devices. By default, Spectrum attempts to rediscover and recreate these links during scheduled discovery cycles.

How to disable Alarm Suppression and Fault Isolation for select devices in Spectrum?

SYMPTOMS:

• Alarm suppression hides alerts for devices behind a down connection

• Fault isolation logic correlates alarms unintentionally for specific topologies

• Deleted links reappear after Discovery cycles run

Environment

• DX Spectrum OneClick (WebApp)

• Command Line Interface (CLI) vnmsh

• Network Discovery

Cause

Spectrum Discovery automatically identifies and creates relationships (links) between devices to enable root cause analysis and alarm suppression.

Deleting a link without updating the Discovery Profile allows the system to repair the "missing" connection during the next cycle.

Resolution

IMPORTANT: Broadcom recommends this procedure only for specific connections. Disabling link discovery globally affects Fault Isolation capabilities for the entire landscape. Disabling it will cause all models to generate all Alarms they are capable of which could crash the system unexpectedly.

 

PART 1: DELETE EXISTING CONNECTIONS

Method A: OneClick WebApp (UI)

1. LOCATE THE CONNECTION

   • Navigate to the Topology View or the Neighbors tab of the target device.

2. DELETE THE LINK

   • Right-click the connection line (pipe) between the devices. Select "Delete". Confirm the deletion.

Method B: CLI (vnmsh)

1. IDENTIFY MODEL HANDLES

   1. Log in to the SpectroSERVER as the spectrum user and navigate to the vnmsh directory. Use the "show associations" command to find the relationship handles.

   2. Syntax:
      
      ./show associations mh=<Target_Model_Handle> | grep Connects
      
      

   3. Example:
      
      [spectrum@<SSHostName> vnmsh]$ ./show associations mh=0x1000075 | grep Connects
      0x10000b9 192.168.x.x Connects_to 0x1000075 <SSHostName>
      
      

   4. NOTE: The Left Model Handle (lmh) and Right Model Handle (rmh) in this example are lmh=0x10000b9 and rmh=0x1000075.

2. DESTROY THE ASSOCIATION

   1. Run the "destroy association" command using the handles identified above.

   2. Syntax:
      
      ./destroy association rel=<Relation> lmh=<Left_Handle> rmh=<Right_Handle>

   3. Example:
      
      [spectrum@<SSHostName> vnmsh]$ ./destroy association rel=Connects_to lmh=0x10000b9 rmh=0x1000075
      destroy association: are you sure ? y
      destroy association: successful
      
      

   4. VERIFY:

      • Run the "show associations" command again to confirm the output is empty.

      • NOTE: Use the -n flag to suppress confirmation prompts if using this in a script.

 

PART 2: PREVENT REDISCOVERY

To prevent Spectrum from recreating the links during the next discovery cycle, you must modify the Discovery Configuration used for these devices. These chances can also be applied to new Discovery Profile configurations to prevent initial link discovery.

1. MODIFY MODELING OPTIONS

   1. Open the Discovery Console.

   2. Select the specific Discovery Configuration profile that is used to rediscover the device IP(s).

   3. Click "Modeling Options". Uncheck the following based on link type:

      • Create LANs (prevents LAN container connections)

      • Create WANs (prevents WAN container connections)

      • Create 802.3/Link options (prevents interface-to-interface connections)

2. MODIFY SCHEDULING OPTIONS

   1. Click "Scheduling Options".

   2. Ensure "Discover Connections During Scheduled Discovery" is Unchecked.

3. ACTIVATE CONFIGURATION\

   • Save and activate the modified Discovery Profile.

Additional Information

• Documentation: Modeling and Managing Your IT Infrastructure

• Documentation: CLI Command Reference for:

  • show - Displays Object
  • destroy - Destroys Object