Reportedly, Time Warner and Comcast are planning maintenance on their dns servers this morning. Should that happen, subscribers will not be able to connect to websites or other internet based applications. There is a workaround for this, however. If you change the dns entries in your router and/or network adapter to a public dns server, you'll bypass the interruption in service. Plenty of alternate servers are available. For example:
DNS Server 1: 4.2.2.1
DNS Server 2: 4.2.2.2
note: these are working servers.