Turning on the HP Officejet 6950 outside the on-off timer planning the printer changes its IP and HPLIP doesn't found it

[Fabrizio Rovedi]

When I turn on the printer on saturday morning or on sunday, after that I have made the planning with the HP Officejet 6950 printer webpage, from HPLIP in Ubuntu Bionic Behaver, the printer changes its IP.
This is due to a bug in the printer software that see the device as a new printer changing its IP.
Here is the output of hp-doctor...
fabrizio@fabrizio-1TB:~$ hp-doctor

HP Linux Imaging and Printing System (ver. 3.19.3)
Self Diagnse Utility and Healing Utility ver. 1.0

Copyright (c) 2001-18 HP Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

HP Linux Imaging and Printing System (ver. 3.19.3)
Self Diagnse Utility and Healing Utility ver. 1.0

Copyright (c) 2001-18 HP Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

Checking for Deprecated items....
No Deprecated items are found

Checking for HPLIP updates....

HP Linux Imaging and Printing System (ver. 3.19.3)
HPLIP upgrade latest version ver. 1.0

Copyright (c) 2001-18 HP Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

Latest version of HPLIP is already installed.

Checking for Dependencies....

---------------
| SYSTEM INFO |
---------------

 Kernel: 4.15.0-64-generic #73-Ubuntu SMP Thu Sep 12 13:16:13 UTC 2019 GNU/Linux
 Host: fabrizio-1TB
 Proc: 4.15.0-64-generic #73-Ubuntu SMP Thu Sep 12 13:16:13 UTC 2019 GNU/Linux
 Distribution: 12 18.04
 Bitness: 64 bit

-----------------------
| HPLIP CONFIGURATION |
-----------------------

HPLIP-Version: HPLIP 3.19.3
HPLIP-Home: /usr/share/hplip
HPLIP-Installation: Auto installation is supported for ubuntu distro 18.04 version

Current contents of '/etc/hp/hplip.conf' file:
# hplip.conf. Generated from hplip.conf.in by configure.

[hplip]
version=3.19.3

[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/ppd/HP
ppdbase=/usr/share/ppd
doc=/usr/share/doc/hplip-3.19.3
html=/usr/share/doc/hplip-3.19.3
icon=/usr/share/applications
cupsbackend=/usr/lib/cups/backend
cupsfilter=/usr/lib/cups/filter
drv=/usr/share/cups/drv/hp
bin=/usr/bin
apparmor=/etc/apparmor.d
# Following values are determined at configure time and cannot be changed.
[configure]
network-build=yes
libusb01-build=no
pp-build=no
gui-build=yes
scanner-build=yes
fax-build=yes
dbus-build=yes
cups11-build=no
doc-build=yes
shadow-build=no
hpijs-install=no
foomatic-drv-install=no
foomatic-ppd-install=no
foomatic-rip-hplip-install=no
hpcups-install=yes
cups-drv-install=yes
cups-ppd-install=no
internal-tag=3.19.3
restricted-build=no
ui-toolkit=qt4
qt3=no
qt4=yes
qt5=no
policy-kit=no
lite-build=no
udev_sysfs_rules=no
hpcups-only-build=no
hpijs-only-build=no
apparmor_build=yes
class-driver=no

Current contents of '/var/lib/hp/hplip.state' file:
Plugins are not installed. Could not access file: File o directory non esistente

Current contents of '~/.hplip/hplip.conf' file:
[upgrade]
notify_upgrade = true
last_upgraded_time = 1568798232
pending_upgrade_time = 0
latest_available_version = 3.17.10

[settings]
systray_visible = 0
systray_messages = 0

[last_used]
device_uri = "hpfax:/net/OfficeJet_6950?ip=192.168.1.2"
printer_name =
working_dir = .

[commands]
scan = /usr/bin/xsane -V %SANE_URI%

[refresh]
rate = 30
enable = false
type = 1

[polling]
enable = false
interval = 5
device_list =

[fax]
voice_phone =
email_address =

[installation]
date_time = 05/10/2019 10:11:06
version = 3.19.3

 <Package-name> <Package-Desc> <Required/Optional> <Min-Version> <Installed-Version> <Status> <Comment>

--------------
| COMPILEDEP |
--------------

 gcc gcc - GNU Project C and C++ Compiler REQUIRED - 7.4.0 OK -
 make make - GNU make utility to maintain groups of programs REQUIRED 3.0 4.1 OK -
 libtool libtool - Library building support services REQUIRED - 2.4.6 OK -

------------------------
| General Dependencies |
------------------------

 libcrypto libcrypto - OpenSSL cryptographic library REQUIRED - 1.1.1 OK -
 python-xml Python XML libraries REQUIRED - 2.2.5 OK -
 libnetsnmp-devel libnetsnmp-devel - SNMP networking library development files REQUIRED 5.0.9 5.7.3 OK -
 sane-devel SANE - Scanning library development files REQUIRED - - OK -
 pil PIL - Python Imaging Library (required for commandline scanning with hp-scan) OPTIONAL - 1.1.7 OK -
 pyqt4-dbus PyQt 4 DBus - DBus Support for PyQt4 REQUIRED 4.0 4.12.1 OK -
 libpthread libpthread - POSIX threads library REQUIRED - 2.27 OK -
 python-devel Python devel - Python development files REQUIRED 2.2 2.7.15 OK -
 cups-devel CUPS devel- Common Unix Printing System development files REQUIRED - 2.2.7 OK -
 python-dbus Python DBus - Python bindings for DBus REQUIRED 0.80.0 1.2.6 OK -
 cups-ddk CUPS DDK - CUPS driver development kit OPTIONAL - - OK -
 reportlab Reportlab - PDF library for Python OPTIONAL 2.0 3.4.0 OK -
 pyqt4 PyQt 4- Qt interface for Python (for Qt version 4.x) REQUIRED 4.0 4.12.1 OK -
 libusb libusb - USB library REQUIRED - 1.0 OK -
 cups-image CUPS image - CUPS image development files REQUIRED - 2.2.7 OK -
 python2X Python 2.2 or greater - Python programming language REQUIRED 2.2 2.7.15 OK -
 python-notify Python libnotify - Python bindings for the libnotify Desktop notifications OPTIONAL - - OK -
 libjpeg libjpeg - JPEG library REQUIRED - - OK -
 sane SANE - Scanning library REQUIRED - - OK -

----------------------
| Scan Configuration |
----------------------

 scanext Scan-SANE-Extension REQUIRED - 3.19.3 OK -
 hpaio HPLIP-SANE-Backend REQUIRED - 3.19.3 OK 'hpaio found in /etc/sane.d/dll.conf'

-------------------------
| External Dependencies |
-------------------------

 gs GhostScript - PostScript and PDF language interpreter and previewer REQUIRED 7.05 9.26 OK -
 scanimage scanimage - Shell scanning program OPTIONAL 1.0 1.0.27 OK -
 cups CUPS - Common Unix Printing System REQUIRED 1.1 2.2.7 OK 'CUPS Scheduler is running'
 network network -wget OPTIONAL - 1.19.4 OK -
 policykit PolicyKit - Administrative policy framework OPTIONAL - 0.105 OK -
 xsane xsane - Graphical scanner frontend for SANE OPTIONAL 0.9 0.999 OK -
 dbus DBus - Message bus system REQUIRED - 1.12.2 OK -
 avahi-utils avahi-utils OPTIONAL - 0.7 OK -

---------------------
| Python Extentions |
---------------------

 hpmudext IO-Extension REQUIRED - 3.19.3 OK -
 cupsext CUPS-Extension REQUIRED - 3.19.3 OK -

------------------------------
| DISCOVERED SCANNER DEVICES |
------------------------------

device `hpaio:/net/OfficeJet_6950?ip=192.168.1.2' is a Hewlett-Packard OfficeJet_6950 all-in-one
device `hpaio:/net/officejet_6950?ip=192.168.1.3&queue=false' is a Hewlett-Packard officejet_6950 all-in-one

--------------------------
| DISCOVERED USB DEVICES |
--------------------------

No devices found.

---------------------------------
| INSTALLED CUPS PRINTER QUEUES |
---------------------------------

OfficeJet_6950
--------------
Type: Printer
Device URI: hp:/net/OfficeJet_6950?ip=192.168.1.2
PPD: /etc/cups/ppd/OfficeJet_6950.ppd
warning: Failed to read /etc/cups/ppd/OfficeJet_6950.ppd ppd file
PPD Description:
Printer status: la stampante OfficeJet_6950 è inattiva. è stata abilitata da lun 30 set 2019 08:18:41 CEST
error: Unable to communicate with device (code=12): hp:/net/OfficeJet_6950?ip=192.168.1.2
error: unable to open channel
error: Communication status: Failed

OfficeJet_6950_fax
------------------
Type: Fax
Device URI: hpfax:/net/OfficeJet_6950?ip=192.168.1.2
PPD: /etc/cups/ppd/OfficeJet_6950_fax.ppd
warning: Failed to read /etc/cups/ppd/OfficeJet_6950_fax.ppd ppd file
PPD Description:
Printer status: la stampante OfficeJet_6950_fax è inattiva. è stata abilitata da lun 30 set 2019 08:18:41 CEST
error: Unable to communicate with device (code=12): hpfax:/net/OfficeJet_6950?ip=192.168.1.2
error: unable to open channel
error: Communication status: Failed

--------------
| PERMISSION |
--------------

Checking Permissions....

Checking for Configured Queues....
warning: Fail to read ppd=/etc/cups/ppd/OfficeJet_6950.ppd file
warning: Insufficient permission to access file /etc/cups/ppd/OfficeJet_6950.ppd
warning: Could not complete Queue(s) configuration check

Checking for HP Properitery Plugin's....
No plug-in printers are configured.

Checking for Printer Status....
error: 'OfficeJet_6950' Printer is either Powered-OFF or Failed to communicate.
Turn On Printer and re-run hp-doctor
error: 'OfficeJet_6950_fax' Printer is either Powered-OFF or Failed to communicate.
Turn On Printer and re-run hp-doctor

Diagnose completed...

More information on Troubleshooting,How-To's and Support is available on http://hplipopensource.com/hplip-web/index.html

[Fabrizio Rovedi (linux.user)]

If you are making an upgrade I strongly suggest that from the printer it's possible to make:
SCAN TO: - Simple Scan
         - Sane
         - Writer of LibreOffice
either from the 'multiple pages feeder' or from the 'plane glass'.

[Fabrizio Rovedi (linux.user)]

It wasn't Sane but Xsane 0.999 of Oliver Rauch

[Fabrizio Rovedi (linux.user)]

You have released the new software but it doesn't works.

[Fabrizio Rovedi (linux.user)]

For the daylight saving time should be better to integrate in the software printer the automatic time change and a synchronism with a time server.