hi i am having problems connecting to internet using ethernet,in the network diagnostics i get all green,except network settings which is orange.i am running mountain lion on intel imac

hi still having problems getting ethernet connection,tried all most everything to my capabilities ,have all green lights on ethernet in network status and all green lights in wireles status,but when i turn wireless off i loose settings for the ethernet connection,i have ethernet at top of list in service order,i am using power line adaptors for the ethernet,wireless works great but just had fibre broadband fitted and was told that the speed would be improved through ethernet cable.

hi have done as you said plug ethernet straight into computer and into back of router,and worked straight off,i had the the powerline on extention when imac was up stairs,when i had computer down stairs it still would not work with powerlines even on main wall sockets,so they are getting binned,looks like i will have to move router upstairs,just wondering if i got extention wire from back of openreach box to router upstairs```,would it be ok,,the openreach box is next to my only phone socket in house,which is in back kitchen..any advice would be great,