Unfortunately, sometimes Comcast is your only internet option. And sometimes you want to configure a Time Capsule as a wireless router for your parents, who happen to have Comcast. So you plug in the Time Capsule, configure it using Airport Utility, and it doesn’t work.
Well, that is no surprise, because you have Comcast, the worst internet provider on the planet. You would think you could just plug in a new device into a comcast cable modem, but you would be wrong. So you follow these instructions to Get Apple Time Capsule to work with Comcast.
Apparently that is all it takes for most people. But after I followed those steps, the Time Capsule could connect to your Comcast cable modem, but when I tried to use the Time Capsule as a wifi access point, I discovered that something was still borked. I couldn’t load any web page, DNS fails, you can’t ping any IP address, etc.
Here is how I got a Time Capsule configured with Comcast.
1. Follow those Get Apple Time Capsule to work with Comcast steps from above.
2. Now, with your Time Capsule connected to your cable modem with an ethernet cable, you open up Airport Utility and see something like the screen shot below. There is a little green dot next to your Time Capsule, but a orange dot next to the Internet icon, and clicking on the Internet icon says “Disconnected”.
3. I don’t know why, but my Time Capsule started up configured in Bridge mode. We need to change it to DHCP+NAT mode. In Airport Utility, click on the Time Capsule icon, and choose Edit (see the bottom arrow in the screen shot above.
4. Choose the Network tab, as shown below. Change from Bridge mode to DHCP and NAT mode.
5. Click the Network Options… button at the bottom to set your IPv4 range. I changed it from 10.10 (the default) to 192.168, as shown below.
Save your settings, and you should be good to go!