Wow. Never heard of anything like that happening before.
I’m confused over your terms. When you say the WD took the gateway’s address, do you mean:
1- The WD took the DEFAULT gateway’s IP (as in, the ROUTER’S address), or
2- The WD took the IP address of your captive portal?
1- This would be an EXTREMELY rare event. If such things were happening commonly, we’d see LOTS of reports of people’s home networks going down whenever the WD’s came up. This just doesn’t happen.
2- This would be impossible unless your network’s DHCP server provided the WD WITH the IP address of the portal to use as its own address.
But even if BOTH of those things COULD happened, I would have to say that’s a questionable hotspot implementation.
Sounds like ANYONE could easily hijack all the portals in your hotspots and phish / snoop to their hearts’ content.
Most “hotspot” services employ protections against “man-in-the-middle” issues, which is what you’re describing.
What hotel chains do you support? I need to make sure I never use the service there. :smileyvery-hap