Create bookmarks for servers which url depends on wheater you are connected to an spefic WLAN or not.
Your dsl router does not support a loopback for your internal websites and you don't want to create to bookmarks. So use this tool to reach your website with a url which depends on the network you are connected to.
External address: http://dyn.example.com/website
Internal address: http://192.168.0.10/website