Command to disconnect from LAN without pulling out RJ45 plug

[daggett]

I need to be able to do what I know I was able to do a long time ago on other Linux distributions - to disable the RJ45 connection at the back of my desktop computer without having to pull out the RJ45 cable.

Could anyone advise me how to do this?

I would prefer to use a text command rather than to use a GUI network management GUI program.

Thank you for your attention.

daggett

[mithrial]

ip link set x down

Where x is your ethernet interface (would be eth0 after old naming rules but it’s probably something else starting with an e)

(The reverse command would be ip link set x up

[merlock]

@mithrial

would be eth0 after old naming rules but it’s probably something else

I absolutely detest the predictable network interface naming scheme. Thankfully, you can force the interface name.

inxi -n --filter
Network:   Device-1: Intel Ethernet I219-V driver: e1000e 
           IF: eth0 state: up speed: 1000 Mbps duplex: full mac: <filter> 

[daggett]

Thank you, mithrila and merlock,

Those responses were very informative, even though I no longer think I need to have my Desktop computer even momentarily disconnected from the Internet using:

ip link set x down

… as you have kindly shown me.

I realise that it is likely that the following may not be of much interest to this discussion, however:

My (possibly misguided) motivation was to be able to make a new minimal installation of Manjaro on a disk where Manjaro is already installed.

That minimal Manjaro Linux installation was to run a trial Drupal (https://drupal.org) content management server without all the usual programs for Desktop use - firefox, chromium, kate, gnumeric, gimp, inkscape, etc. etc.

I had (naively?) hoped that if I used a manjaro-xfce-21.04-210506-linux310.iso with no connection to the Internet, I would be more likely to get such a minimal installation, to which I would then add Drupal (version 9), Apache, PHP and MariaDB or Percona (https://www.percona.com/) as a replacement for Mysql.

However, that initial Manjaro installation made without an Internet connection seemed unworkable. So I overwrote that installation by again installing manjaro-xfce-21.04-210506-linux310.iso, but this time with the Desktop Computer connected.

Possibly I should be using BSD, of which I have little understanding, or some other Linux distro which may be more focused on working as a server, if there are such distros.

I am still some way off getting my Drupal CMS to work.