What is the name of the applet used to make changes to the computer’s network adapter ?

Answer the important painting of the baptism of the christ, leonardo painted the kneeling angel and some of the background for this;

I’m not sure but i need to know too

That i would call a dead end, since you can't know that it's always possible to immediately reconnect (server could be down, lines between you and the server could be down), and even if it was this would take some time slipping the packages out your wan in the meantime.the solution to this problem rather like satras says to block wan access for those hosts, and if policy routing is being used you need to use the soltion found by fastlanejb in this thread:   the link to the problem forum