My problem is that when I connect a second time capsule via ethernet, my wi-fi disappears from availability on all devices. I can use a wi-fi connection between the two time capsules but it doesn't give me the performance I was hoping for.
When I open Airport Utility, I get a very different interface than the one above. I see a dark gray screen with three nodes set atop one another. The top is "Internet," next is TC1 and next is TC2. I am not seeing the option to "share a public IP address."