I have performed a new/clean install of v20.04 on a Leno T470s laptop. No problems with installation, all bits appear to work. Very happy up to now.

However, every time I boot my laptop (and even while working or even idle), my EPSON WF-7520 LAN printer is probed (discovered/browsed). It is driving me and the family nuts because the probe make the printer react as if it has just initialised. This occurs even if I have not added a printer. The printer is not "automatically" added. I have added the printer manually.

I have tried (after much searching):

  1. editing /etc/cups/cups-browsed.conf,

    $ BrowseProtocols none
    $ BrowseRemoteProtocols none
  2. Disable browsed

    $ sudo systemctl stop cups-browsed
    $ sudo systemctl disable cups-browsed
  3. Removed AVAHI

    $ sudo apt remove avahi
  4. Make sure everything in clean

    $ sudo apt upgrade -y
    $ sudo apt autopurge
    $ sudo apt autoremove
    $ sudo apt autoclean
  5. Checked in case SAMBA was running/discovering things on the network,

    $ sudo systemctl status smbd
    Unit smbd.service could not be found.
  6. I checked,

    $ sudo lpinfo -v
    file cups-brf:/
    network ipps
    network ipp
    network beh
    network https
    serial serial:/dev/ttyS0?baud=115200
    serial serial:/dev/ttyUSB0?baud=230400
    serial serial:/dev/ttyUSB1?baud=230400
    network socket
    network http
    network lpd
    network lpd://
 is my LAN printer IP.

  7. Removed CUPS

    $ sudo apt remove avahi

    Make sure everything in clean

    $ sudo apt upgrade -y
    $ sudo apt autopurge
    $ sudo apt autoremove
    $ sudo apt autoclean

    The problem still persists. This means it is not CUPS or AVAHI.

  8. I reinstalled CUPS

    $ sudo apt install CUPS

For completeness I have included a list of running services in case it provides any insight,

$ systemctl list-units --all --type=service | grep running
    accounts-daemon.service                               loaded    active   running Accounts Service                                                                
  acpid.service                                         loaded    active   running ACPI event daemon                                                               
  atd.service                                           loaded    active   running Deferred execution scheduler                                                    
  avahi-daemon.service                                  loaded    active   running Avahi mDNS/DNS-SD Stack                                                         
  bluetooth.service                                     loaded    active   running Bluetooth service                                                               
  bolt.service                                          loaded    active   running Thunderbolt system service                                                      
  colord.service                                        loaded    active   running Manage, Install and Generate Color Profiles                                     
  cron.service                                          loaded    active   running Regular background program processing daemon                                    
  dbus.service                                          loaded    active   running D-Bus System Message Bus                                                        
  expressvpn.service                                    loaded    active   running ExpressVPN Daemon                                                               
  fwupd.service                                         loaded    active   running Firmware update daemon                                                          
  gdm.service                                           loaded    active   running GNOME Display Manager                                                           
  irqbalance.service                                    loaded    active   running irqbalance daemon                                                               
  kerneloops.service                                    loaded    active   running Tool to automatically collect and submit kernel crash signatures                
  libvirtd.service                                      loaded    active   running Virtualization daemon                                                           
  ModemManager.service                                  loaded    active   running Modem Manager                                                                   
  networkd-dispatcher.service                           loaded    active   running Dispatcher daemon for systemd-networkd                                          
  NetworkManager-dispatcher.service                     loaded    active   running Network Manager Script Dispatcher Service                                       
  NetworkManager.service                                loaded    active   running Network Manager                                                                 
  polkit.service                                        loaded    active   running Authorization Manager                                                           
  rsyslog.service                                       loaded    active   running System Logging Service                                                          
  rtkit-daemon.service                                  loaded    active   running RealtimeKit Scheduling Policy Service                                           
  snapd.service                                         loaded    active   running Snap Daemon                                                                     
  switcheroo-control.service                            loaded    active   running Switcheroo Control Proxy service                                                
  systemd-journald.service                              loaded    active   running Journal Service                                                                 
  systemd-logind.service                                loaded    active   running Login Service                                                                   
  systemd-machined.service                              loaded    active   running Virtual Machine and Container Registration Service                              
  systemd-resolved.service                              loaded    active   running Network Name Resolution                                                         
  systemd-timesyncd.service                             loaded    active   running Network Time Synchronization                                                    
  systemd-udevd.service                                 loaded    active   running udev Kernel Device Manager                                                      
  teamviewerd.service                                   loaded    active   running TeamViewer remote control daemon                                                
  thermald.service                                      loaded    active   running Thermal Daemon Service                                                          
  udisks2.service                                       loaded    active   running Disk Manager                                                                    
  unattended-upgrades.service                           loaded    active   running Unattended Upgrades Shutdown                                                    
  upower.service                                        loaded    active   running Daemon for power management                                                     
  user@1000.service                                     loaded    active   running User Manager for UID 1000                                                       
  wpa_supplicant.service                                loaded    active   running WPA supplicant

What is probing my printer?

Is there a "switch" of some type I have missed that will disable this "discovery" process from probing my printer?

Any assistance would be appreciated.

thanks, dg


Your Ubuntu system does not probe the network; that would be an active process. cups-browsed and and avahi-daemon are passive discoverers of DNS-SD traffic on the network. In your case, the WF-7520 would be generating some (perhaps all) of this traffic.

So turn off Bonjour and/or IPP on the WF-7520 from its web interface and see how you go on.

  • hi Thomas, thank you for your prompt advice. I checked the config of the printer, – dgoogle Sep 24 '20 at 0:57
  • hi Thomas, thank you for your prompt advice. I checked the config of the printer, 1. I found the reference to AirPrint Setup (Bonjour Service) 2. no option to turn it off 3. I set the IP to be but the problem persists. All other laptops on the network are windows based and don't trigger this behaviour on the printer. :-( – dgoogle Sep 24 '20 at 1:51
  • Rethinking the test I have performed, I unsintalled Avahi and CUPS (Points 3 and 7 above) and the problem persists. All I know that when I turn on or log on to Ubuntu it triggers the printer. – dgoogle Sep 24 '20 at 9:38
  • What do you mean by "triggers the printer"? If it happens without CUPS on the system, it is obviously not a printing problem. – brian_p Sep 25 '20 at 21:50
  • whenever I start my laptop the printer goes through its "reset" process, like when it is first powered on. It's a MFP, the scanner goes through its passes. If I log in from a locked screen, the say happens. – dgoogle Sep 28 '20 at 6:42

Remove cups-browsed

Remove the process responsible for this behaviour as suggested here:

$ sudo apt remove cups-browsed
  • 1
    hi Serge, thank you for the suggestion. I have turned off cups-browser, I've rebooted a couple of times and can confirm that cups-browser is not running. – dgoogle Oct 6 '20 at 10:52
  • @dgoogle Thank you in advance for an upvote ;-) – Serge Stroobandt Oct 6 '20 at 11:36

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