Krdytkyu

I successfully set up Tinc VPN between my Desktop, two laptops and an external VPS which is always visible through Internet.

All of them are Ubuntu 18.04 (all upgraded from earlier versions except one of the laptops which is a fresh install).

I can see (and ssh, ping, etc...) all computers at their VPN IPs either from my home LAN or from Internet (using my smartphone as 4G gateway).

I also have two local printers configured in my Desktop PC which I can access and use from both laptops while connected to our LAN.

But that's not true when the only connection is throught the VPN.

I even tried to manually add remote printers through Ubuntu Printers configuration panel and, if I specify its (VPN) IP address, I also achieved to see them. But when I try to add I must manually select the driver and after that I end up getting an error message telling me that the printer couldn't be added.

That happen all times I try to add the printers through the desktop's VPN IP no matter if the laptop is connected to the VPN through our LAN or through G4 connection.

In both cases an nmap 10.0.0.2 (which is the Desktop VPN IP) gives the exact same output as the same command to its LAN IP (when connected to the LAN through which pringers are automatically available).

Here it is an extract Desktop's /etc/cups/cupsd.conf:

LogLevel warn                                                                          │ ms

PageLogFormat                                                                          │joanmi@turkey:~$ sudo nmap 192.168.1.10

MaxLogSize 0                                                                           │

# Allow remote access                                                                  │Starting Nmap 7.60 ( https://nmap.org ) at 2018-12-27 16:58 CET

Port 631                                                                               │Nmap scan report for 192.168.1.10

Listen /var/run/cups/cups.sock                                                         │Host is up (0.010s latency).

# Share local printers on the local network.                                           │Not shown: 989 closed ports

Browsing On                                                                            │PORT     STATE SERVICE

BrowseLocalProtocols dnssd                                                             │22/tcp   open  ssh

DefaultAuthType Basic                                                                  │80/tcp   open  http

WebInterface Yes                                                                       │111/tcp  open  rpcbind

<Location />                                                                           │139/tcp  open  netbios-ssn

  # Allow shared printing...                                                           │443/tcp  open  https

  Order allow,deny                                                                     │445/tcp  open  microsoft-ds

  Allow @LOCAL                                                                         │631/tcp  open  ipp

  Allow 10.0.0.*                                                                       │2049/tcp open  nfs

</Location>      

Also from local (laptop) /var/log/cups/error_log

W [27/Dec/2018:16:56:11 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id 'Brother_HL_1430_series_constructor-Gray..' already exists

E [27/Dec/2018:16:56:11 +0100] [Client 848] Returning IPP client-error-bad-request for CUPS-Add-Modify-Printer (ipp://localhost:631/printers/Brother_HL_1430_series_constructor) from localhost

W [27/Dec/2018:16:56:11 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id 'DCP9020CDW_constructor-Gray..' already exists

W [27/Dec/2018:16:56:11 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id 'DCP9020CDW_constructor-RGB..' already exists

E [27/Dec/2018:16:56:11 +0100] [Client 860] Returning IPP client-error-bad-request for CUPS-Add-Modify-Printer (ipp://localhost:631/printers/DCP9020CDW_constructor) from localhost

W [27/Dec/2018:16:56:11 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id 'Brother_DCP_9020CDW-Gray..' already exists

W [27/Dec/2018:16:56:11 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id 'Brother_DCP_9020CDW-DeviceN..' already exists

E [27/Dec/2018:17:12:15 +0100] [cups-deviced] PID 7283 (gutenprint52+usb) stopped with status 1!

E [27/Dec/2018:17:14:43 +0100] [cups-deviced] PID 7390 (gutenprint52+usb) stopped with status 1!

E [27/Dec/2018:17:29:36 +0100] [cups-deviced] PID 7605 (gutenprint52+usb) stopped with status 1!

...also similar "already exists" messages can be found in the same log on the Desktop so I suspect on some kind of conflict because the printers were already known by the laptop.

But whan accessing through 4G it remains the same so I have no clue on what is going on...

Any help would be appreciated.