A large number of customers of telecommunications giant Comcast are reporting tonight that they cannot connect to the Internet, reportedly because of a widespread DNS (domain name system) server outage.
The Domain Name System, for readers who don’t know, is like the Internet’s phone book. It is a crucial part of the Internet’s application layer. DNS servers perform lookups — they route requests for domain names like nwprogressive.org to the computers where websites like NPI’s are served from.
When a DNS server goes down, requests to resolve domain names time out and fail, resulting in connectivity problems. A DNS outage can be resolved by switching to a different public DNS server or pair of DNS servers offered by a company like OpenDNS or an alternative Internet service provider. But this requires some degree of technical expertise, which a lot of people simply don’t have.
Comcast says it’s aware of the problem and working to fix it, but in the meantime, customers who aren’t technologically savvy enough to figure out how to ditch Comcast’s DNS servers are out of luck.
Video tutorials for changing DNS servers are available on YouTube. Here’s one for Mac OS X, and here’s one for Windows. If you run a GNU/Linux distribution, you’re probably savvy enough to know how to change DNS servers.
What should you change your DNS servers to, if you want to ditch Comcast’s DNS? One option is OpenDNS, which is known for its rock solid reliability.
For faster performance, a better option might be Speakeasy/MegaPath, which scores well in the DNS tests that NPI has run.
Still another option is Level3, which provides Internet service providers with their connection to the Internet backbone.
Any of these options is better than Comcast.