For the second time in a week, Comcast customers found themselves unable to connect to the Internet. This time, it was Comcast subscribers in the Midwest who had to endure a Sunday evening without being able to use their Internet service. Portions of four states were affected: Michigan, Illinois, Indiana, and Minnesota. The outage began around 8:30 PM on Sunday and lasted until around midnight. Comcast apologized for the problem through a customer service Twitter account.
Just a week before, on the eve of Cyber Monday, Comcast subscribers in areas in and around Washington, D.C. and Boston found they were unable connect to the Internet for several hours throughout the evening.
Both of the outages are blamed on glitches with Comcast’s Domain Name System (DNS), the system which translates IP addresses into their corresponding domain names. In both cases, users were able to reconfigure their Internet settings to use a alternative DNS settings — like OpenDNS or Google’s Public DNS, — in order restore connectivity. Comcast subscribers already configured to use different DNS settings were not affected by the outage. Cable TV and phone service were also unaffected.