Get help with multiple-NAT configurations for Back to My Mac

In these cases, your routers could be providing too many layers of NAT. A multiple-NAT configuration happens when at least one router in the network is connected to another router, and each one provides NAT. For example, if your cable modem is providing NAT, and you connect an AirPort Base Station to the modem using the default AirPort settings, the AirPort Base Station might provide another layer of NAT. To resolve the issue, follow the steps below. If you're on a corporate network, contact your network administrator for help.