OK,
Regarding the missing informations:
We are in a lan conected to a dsl connection.
No proxy server, we directly connect to the gateway: 10.0.0.1
Nobody works with DHCP. We asssigned a permanent Ip address to every computer in the lan.
To answer your question, my knowledge of the problem is very poor. I have to acknowledge I am a bit lost. My native language is french, and what you tell me (ethx entry, eth0, netconf...) looks, for a newnewbie like me, like chinese .
WHere do I run ifconfig? In a console?
What is a ethx entry? How can I know if I have one?
How do I run netconf? In a console?
What is Slack?...
Anyway, thanks for your concern.
Maybe someone have an idea of the solution...
HELP!! I am a

!!!