Avamar: Error 52001 (Communications Module Scanner Error) due to disabled switch Telnet server

Summary: An Avamar Gen5A system reports a communications module scanner error, caused by the Telnet server on the Dell S4128F-ON switch being disabled.

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Symptoms

The following error is reported in the Avamar User Interface, and is also seen when running the mccli command below:

admin@avamar:~/>: mccli event show --unack
0,23000,CLI command completed successfully.
ID   Date                    Type  Code  Category Severity Domain Summary
---- ----------------------- ----- ----- -------- -------- ------ -----------------------------------
...
2381 2025-10-08 10:22:48 AST ERROR 52001 SYSTEM   PROCESS  /      Communications Module Scanner Error

The switch_monitoring log on the Avamar utility node shows only the following entries, repeating:

admin@avamar:~/>: tail -50 /usr/local/avamar/var/log/switch_monitoring.log
...
2025/10/01-09:28:09 INFO: simulating error codes =
2025/10/01-09:28:12 INFO: publish() cmd="mccli event publish --code=52001 " successful
2025/10/01-09:49:48 INFO: simulating error codes =
2025/10/01-09:49:51 INFO: publish() cmd="mccli event publish --code=52001 " successful
2025/10/01-10:43:01 INFO: simulating error codes =
2025/10/01-10:43:04 INFO: publish() cmd="mccli event publish --code=52001 " successful

Attempting to connect to the internal switches using Telnet returns a connection refused message.

Note: The switch A IP address is conventionally 192.168.255.200, and switch B is 192.168.255.201. However, the switch IP addresses may differ from this depending on the system configuration. Steps to gather the switch IP addresses are provided in the resolution section of this article. 
admin@avamar:~/>: telnet 192.168.255.200
Trying 192.168.255.200...
telnet: connect to address 192.168.255.200: Connection refused
admin@avamar:~/>: telnet 192.168.255.201
Trying 192.168.255.201...
telnet: connect to address 192.168.255.201: Connection refused
admin@avamar:~/>:

Attempting to connect to the internal switches using ssh is successful.


  
admin@avamar:~/>: ssh admin@192.168.255.200
Debian GNU/Linux 10

Dell SmartFabric OS10 Enterprise
admin@192.168.255.200's password:
...
admin@avamar:~/>: ssh admin@192.168.255.201
Debian GNU/Linux 10

Dell SmartFabric OS10 Enterprise
admin@192.168.255.201's password:
...

        
Cause

        
The Telnet server on the internal Avamar Dell S4128F-ON switches is disabled.

        
Resolution

        
    
   
  1. Log in to the affected Avamar utility node as the admin user using ssh.
    2. 
   
  2. Confirm the switch IP addresses by running the following command:
    
    
    nodedb print | grep -A1 "switch id"
    3. 
   
  3. Retrieve the switch password from the system lockbox by running the following command:
    
    
    avlockbox.sh -r switch-A-password
    4. 
   
  4. Connect to the first switch (switch A) as the admin user using ssh. Use the IP address for switch A gathered in step 2, and the password gathered in step 3.
    
    
    admin@avamar:~/>: ssh admin@192.168.255.200
Debian GNU/Linux 10

Dell SmartFabric OS10 Enterprise
admin@192.168.255.200's password:
...
dell-swa#
    5. 
   
  5. Run the following commands to enable the Telnet server, and then disconnect from the switch: 
    
    dell-swa# configure
dell-swa(config)# ip telnet server enable
dell-swa(config)# exit
    6. 
   
  6. Connect to the second switch (switch B) as the admin user using ssh and repeat step 3. Use the IP address for switch B gathered in step 2, and the password gathered in step 3.
    
    
    admin@avamar:~/>: ssh admin@192.168.255.201
Debian GNU/Linux 10

Dell SmartFabric OS10 Enterprise
admin@192.168.255.201's password:
...
dell-swb# configure
dell-swb(config)# ip telnet server enable
dell-swb(config)# exit
    7. 
  


                    
Additional Information

        
The following knowledge-base article contains detailed steps for enabling/disabling telnet/ssh access that apply to all switches running the Dell SmartFabric OS10 operating system:
Dell EMC Networking OS10 Switches How to Enable/Disable Telnet/SSH




        

        
        
Affected Products

        Avamar, Avamar Data Store, Avamar Data Store Gen5A, Avamar Server







                        

                            

    

        

            

                
                    
 Article Properties

                
            

            

                

                        
Article Number: 000400243

                

                
                

                        
Article Type: Solution

                

                

                        
Last Modified: 05 Dec 2025


                

                    

                            
Version:  1

                    


            


        

    

    

        

            

                
                    
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