I am a business using tmobileisp wireless modem (FX2000-3) as a failover connection (WAN2) using IP Passthrough. Xfinity is primary (WAN). Using a Tp-Link ER605 router. Everything is perfect. Failover works great, with one exception. When WAN2 is routing traffic, like the primary WAN is fully disconnected, I am unable to connect through DDNS. I'm showing an IP address (100.x.x.x) in the router AND in the ingosee control panel, and this is fully accessible from an outside connection. But it shows a completely different IP address on (for example) whatismyipaddress.com. that is neither my WAN OR my WAN2 connection. It's 78.x.x.x Can anyone give me input to where this IP address is coming from? And is this normal?