A misconfigured router caused a major slowdown in internet traffic on Monday after problems with overly long global Border Gateway Routing (BGP) Autonomous System (AS) numbers.

The source of the problem appears to be with AS 47868, which caused AS paths to become too long, according to Marcus Sachs, director of the Sans Internet Storm Center.

"Not much you can do about it unless you have access to your BGP router, in which case you might want to block AS 47868 or limit the length of any AS path, " he said.

The problems have apparently been traced to a router run by Czech ISP SuproNet, which issued a router update that affected some other routers running older firmware. The overly long AS numbers then caused delays in processing data traffic.

"We experienced an almost 100-fold increase in the rate of routing updates from our worldwide array of sensors," said internet monitoring firm Renesys in a blog post.

"We were heartened to see that most of the internet's core survived a single odd announcement, but this does speak to a lot of outdated equipment or software at the edge. And if you manage to get all of your edge routers to reset, you aren't going to have many people to talk to no matter what the core is doing.

"While it might be tempting to bash SuproNet, can anyone really defend a system where a failure in one of the weaker links can cause the entire system to unravel?"

Renesys pointed out that the bulk of the problems were with older routers, and that less developed markets like Africa took the hardest hit. But networks were seriously affected in Europe, particularly France, and in the US.