I’m not sure of what the problem is from, but here’s what you could try:
-add the argument -S to your command; it forces check_http to use SSL (as your web page is in https).
-also, 403-Forbidden can also come from the fact you didn’t provide a user/password. Does your web page ask you a login/pass when you open it with your web browser ? if so, you may try to add the login/pass in your url: USER:[email protected]/sys/var … m_1.LC0800.[1].nvoSwitch_1%23state&UID=root,PW=root
=> but be aware, if that works, that your credentials will be in clear text in your conf files…