By John Oates • Get more from this author
Posted in Telecoms, 27th July 2009 16:18 GMT
US internet service provider and telco AT&T has restored access to 4chan, blaming a denial of service attack, not smutty content, for the temporary ban.
4chan has been under attack for some weeks now
A spokesman for AT&T said:
Beginning Friday, an AT&T customer was impacted by a denial-of-service attack stemming from IP addresses connected to img.4chan.org. To prevent this attack from disrupting service for the impacted AT&T customer, and to prevent the attack from spreading to impact our other customers, AT&T temporarily blocked access to the IP addresses in question for our customers.This action was in no way related to the content at img.4chan.org; our focus was on protecting our customers from malicious traffic. Overnight Sunday, after we determined the denial-of-service threat no longer existed, AT&T removed the block on the IP addresses in question. We will continue to monitor for denial-of-service activity and any malicious traffic to protect our customers.
According to this discussion - thanks to a commenter on the original story - other ISP engineers took similar action because of a distributed denial of service attack. The engineer in this case claims he took the action in agreement with the owner of 4chan's hosting service.
Denial of service attacks take several forms but are a way of overwhelming a webserver, usually, with massive numbers of requests so that it slows or goes offline completely. Attackers can also use automated reply responses to go after other sites by faking the source address information. ®