After using fixed-IP DSL for many years, I'm still pretty new to DHCP, which I previously only used as a Guest at others' residences
or offices. The other day, I lost the internet connection towards the end of a few-hours session.  *Every* attempted URL then became a 'Page Not Found.'  This hardly ever happened with the fixed IP + DSL, and when it did it was very obvious that it was some major event, like the local or regional AT&T broadband service being down.  (I think that is much more common around S.D., with TWC, where someone will dig up a cable somewhere in the area, and then Kablooey.)

  

But that's not really the kind of major service interruption I'm talking about.  Far more common is something I've seen at a relative's place, where some kind of "sync" is lost between PC, router, and cable modem, where the connection is re-established by rebooting each of these in a certain order.  I think that what I saw the other day is much more common still, and involves loss / non-renewal of the DHCP lease.  That is, I probably do not need to reboot the computer, or the router, or the cable modem.  So, my question: What is the command (or GUI object, or widget) in eCS to force a new cable connection &/or new lease ?  (And, what is the equivalent thing you can try in Windoze ?  If I was a 'Nix user, I'd ask about that one too.)