Comcast subscribers might be surprised to find out their cable modem is being used as a public Wi-Fi hotspot. If you want to turn this off, you'll have to head to your account settings to opt-out.


The public Wi-Fi hotspot feature turns your Comcast modem into an access point for others to connect to when they need to go online. It isn't necessarily a terrible thing. It gives Comcast subcribers internet access on the go—and, because the shared wireless network is completely separate from your home one, your bandwidth and security shouldn't be affected. However, as Comcast's FAQs on the matter state, your home Wi-Fi network could be affected simply because there's another hotspot (yours!) on the block [emphasis mine]:

The broadband connection to your home will be unaffected by the XFINITY WiFifeature. Your in-home WiFi network, as well as XFINITY WiFi, use shared spectrum, and as with any shared medium there can be some impact as more devices share WiFi. We have provisioned the XFINITY WiFi feature to support robust usage, and therefore, we anticipate minimal impact to the in-home WiFi network


It'd be nice if this were opt-in, but since it's not, here's where to go to turn the public Wi-Fi feature off if you're so inclined: Log in at http://customer.comcast.com, then click My Account > Users & Preferences in the top navigation bar, and under your service address, click the "Manage XFINITY WiFi" link.

When was the last time you checked your Comcast cable modem settings? | Internet Storm Center