There are a vast number of software applications out there to help you in this situation. Here are a few that I think are worth checking out.......... ManageEngine offers the Switch Port Mapper Tool, which handles multiple brands of switches and imports cable port mappings. See the ManageEngine site for detailed pricing information.......
Router# copy running-configuration tftp
Built into routers with newer IOS versions is IOS configuration archiving........... Also, there are many third-party GUI applications that will schedule this for you so that you can “set it and forget it.” For example, see my article on Kiwi CatTools and products from ManageEngine OpUtils and........
.... has a gui utility which gives the dns name, ip and mac of devices and which port they are plugged into. There is a free utility Oputils that is good also.