prevent an app to connect to a website

[ckonn]

would like to know how can one force an application/s not to connect to its website in internet?

there are such apps, which by default are checking does the pc is connected to the net and if they detect an
internet-connection they automatically connect to their own website.

do not mean 'client-server-architecture' apps, which work only if there is internet connection available,
but apps that can work without internet-connection.

almost sure that this can be done with some short bash script in .bashrc, but what?

[Flemur]

i do not mean client - server architecture apps, which work only if there is internet connection available,
but apps that can work without internet-connection.

It's possible, but much more convoluted than it should be; rather than a simple "internet-block program-name" you make a new group and run a program under that group:

"How to block internet access to certain programs on Linux"
https://serverfault.com/questions/55027 ... s-on-linux

[phd21]

HI ckonn,

Can you be more specific as to which application(s) you are refering to?

1.) If the application has any update or internet accessing options in their setup, preferences, configurations, turn those off.

2.) I think anyone can use the wonderful "Firejail" sandboxing application to block appplications from accessing the Internet by "black listing" it in the "firejail" configuration file.

How to block a program from accessing the Internet
viewtopic.php?t=216063

Douane is a firewall that filter and limit the outgoing network traffic per application.
https://gitlab.com/douaneapp/Douane

Use the firewall - How to control internet access for each program?
https://askubuntu.com/questions/45072/h ... ch-program

Google search results...
https://www.google.com/search?client=fi ... 29&bih=687

Hope this helps ...

[ckonn]

it seems like the simplest way to prevent an app to connect to internet is to close the port/s it use.

in my case i was dealing with a specific plugin additionally installed on a specific app. this specific plugin was opening
a specific port and listening on it.

by the command 'lsof -i' i saw what exactly port that plugin was opening to listen.
then i just type in the terminal 'ufw deny <port_number>'
and since then the plugin does not listen at this port.

for many forum users all this may sound like the oldest news in the world, but for others it may be helpful.

[catweazel]

there are such apps, which by default are checking does the pc is connected to the net and if they detect an
internet-connection they automatically connect to their own website.

There are several ways. One is to make use of the hosts file so that the site is inaccessible to every application. Another is to run gufw and set up specific rules.

[Pjotr]

2.) I think anyone can use the wonderful "Firejail" sandboxing application to block applications from accessing the Internet

Excellent tip! Easy and effective.

This is the easiest way to achieve that with Firejail:
https://sites.google.com/site/easylinux ... plications
(item 11, right column)