i would not us ethe webinterface for cups… its slow and complicated system-config-printer is easier and can set firewall port to be open too automatically… müsste “Druckereinstellungen” im Menü heissen 
The printer need sto setup to connect to the Router with the printer interface onnthe prionter… because you can not reach the printer if it is not already connected to your local network…
hello dear @joekamprad
many thanks - awesome tipps. - The printer itself is allready connected to the network - i have set up the printer to the WLAN.
now i have a closer look at the so called " Druckereinstellungen" 
well i wonder if it - if i go this way - if it ends up with this
Netzwerk-Drucker finden - well dear Doctor - i think that we are very very close
that’s still the cups webinterface … but okay
you will need to use root as username and your password is if you do not change it the same as your users password…
hello dear friend - srry for the stepwise progression here -
i have now the first step of 5
Drucker hinzufügen
Drucker hinzufügen (Schritt 1/5)
Lokale Drucker: CUPS-PDF (Virtual PDF Printer)
CUPS-BRF (Virtual Braille BRF Printer)
Gefundene Netzwerkdrucker:
Andere Netzwerkdrucker: Internet Printing Protocol (http)
LPD/LPR-Host oder -Drucker
Internet Printing Protocol (ipp)
Backend Error Handler
Internet Printing Protocol (ipps)
AppSocket/HP JetDirect
Internet Printing Protocol (https)
Windows Printer via SAMBA
which one to choose… here
(note: this is the cups-setup menu - and i am in the first of 5 steps here)
on a sidenote: your support is really outstanding…
no problem… i help if i can …
hi but as it seems so:
thanks for the image - and for the guidance but :
on my site no network-printer have been found !?
see the list above -
i guess that i cannot go ahead - to the next step - since i do not have the certain EPSON printer in the list"!? or should i continue any way. !?
Is firewall and /etc/nsswitch.conf setup?
Looks like local hostname resolution is not working or blocked by the firewall.
cat /etc/nsswitch.conf | eos-sendlog
and firewalld:
these 3 must be checked if you open the firewalld gui…
Sometimes a reboot helps also?
yea true. good point… in this case it should not be needed … if you restart network avahi and firewall … but a reboot would be easy instead
[heike@tp14 ~]$ cat /etc/nsswitch.conf | eos-sendlog
https://0x0.st/oUk7.txt
[heike@tp14 ~]$
it is way to complicated to setup a printer … it should not need to adjust so many things…
I mean i know how and can do this blindly but see @otrott he do really endeavour and its still hard to do…
i just set the firewall settings . i marked and checked all the things you mentioned
so i guess i run the printer - step 1 again
wait
update: again only the same results in step 1
Drucker hinzufügen (Schritt 1/5)
Lokale Drucker: CUPS-PDF (Virtual PDF Printer)
CUPS-BRF (Virtual Braille BRF Printer)
Gefundene Netzwerkdrucker:
Andere Netzwerkdrucker: Backend Error Handler
Internet Printing Protocol (http)
Internet Printing Protocol (ipps)
Internet Printing Protocol (ipp)
Internet Printing Protocol (https)
LPD/LPR-Host oder -Drucker
AppSocket/HP JetDirect
Windows Printer via SAMBA
should i restart the whole system!?
local hostname resolution is not set…
you have to edit /etc/nsswitch.conf like so:
# Name Service Switch configuration file.
# See nsswitch.conf(5) for details.
passwd: files systemd
group: files [SUCCESS=merge] systemd
shadow: files systemd
gshadow: files systemd
publickey: files
hosts: mymachines mdns_minimal [NOTFOUND=return] resolve [!UNAVAIL=return] files myhostname dns
networks: files
protocols: files
services: files
ethers: files
rpc: files
netgroup: files
adding mdns_minimal [NOTFOUND=return] before resolve
and on firewalld you need to switch to permanent before setting the options:
and after this reboot is the easiest way to apply the new settings…
first i set the firewall settings to permanent
then i edited the mentioned file
the file looks so -
# Name Service Switch configuration file.
# See nsswitch.conf(5) for details.
passwd: files systemd
group: files [SUCCESS=merge] systemd
shadow: files systemd
gshadow: files systemd
publickey: files
hosts: mymachines mdns_minimal [NOTFOUND=return] resolve [!UNAVAIL=return] files myhostname dns
networks: files
protocols: files
services: files
ethers: files
rpc: files
netgroup: files
mdns_minimal [NOTFOUND=return] before resolve
note - i have added the mdns_minimal … line
now i do a restart
did a RESTART
but in the cups.list i did not find more items as i mentioned above
Drucker hinzufügen
Drucker hinzufügen (Schritt 1/5)
Lokale Drucker: CUPS-BRF (Virtual Braille BRF Printer)
CUPS-PDF (Virtual PDF Printer)
Gefundene Netzwerkdrucker:
Andere Netzwerkdrucker: Internet Printing Protocol (http)
LPD/LPR-Host oder -Drucker
Internet Printing Protocol (ipps)
Internet Printing Protocol (ipp)
Backend Error Handler
Internet Printing Protocol (https)
AppSocket/HP JetDirect
Windows Printer via SAMBA
and besides that i found in the Druckereinstelllungen i found this
Adjust Firewall
Die Firewall muss moeglicherweise angepasst werden um NEtzwerkdrucker finden zu koenne.
Moechten Sid die Firewall jetzt anpassen?!
Allow all incomming IPP Browser packets
Allow all incoming mDNS Traffic
[] do it now
[] do it later
i checked - do it now - and continued…
one is new and it will be yours
Hyja - awesome i did not check and compare - but wow…
i check this and go on to the second page
where we have the following:
Verbindung:
https
Beispiele:
http://hostname:631/ipp/
http://hostname:631/ipp/port1
ipp://hostname/ipp/
ipp://hostname/ipp/port1
lpd://hostname/queue
socket://hostname
socket://hostname:9100
hmmm - i guess that i can continue now to the third page
hmm should be set already… but seems cups is now also able to call the firewall-adjust implementation… that’s good to know…