Technical glitch made site briefly unavailable to some users: Facebook

Social networking site Facebook, with over one billion users worldwide, was briefly unavailable to some account holders on Monday because of a technical glitch.

The site said it made a change to its domain name system setup on Monday, which resulted in some users temporarily not being able to reach the site. The problem was detected and the Facebook site is now fully back .

Facebook did not say how many users were affected or for how long. Some technology blogs say the problems lasted about 20 minutes.

A DNS acts like a phone book for the Internet, translating a domain name like facebook.com into a number that points to a specific host computer.