When a NAT system is doubled up with another NAT system, however, it can create issues for apps (like the Plex Media Server) that rely on UPnP to create automatic port forwarding rules. (howtogeek.com)
This application takes care of port forwarding for you, right from your desktop. (howtogeek.com)
Routers protect their web interfaces — where you can configure their networking, parental control, and port forwarding settings — with a default username and password. (howtogeek.com)