I have a Netgear N600 wireless router. How can I recover my PPPoE from that device? The web interface only shows dots for the password...
Usually the HTML source of the web interface provides the information, even when some display setting hides it. Sometimes it's not that easy, but for most devices I've seen, passwords are just in the source and can be found like this.
An example for an OpenWRT-enabled device here:
Right-click -> View source -> Ctrl+F -> "password"