Starting with June 8th 2009 around 1 p.m. in RoEduNet network we begin to experience problems reaching some destinations in the Internet, including Yahoo and Google. The problem was reported to DANTE (the operator of the European Research and Education Network GEANT) and further to the operator Telia Sonera, the provider for connections between GEANT and Internet. RoEduNet, DANTE and Telia Sonera conducted investigations, including a conference call, and finally the problem was identified as being generated in the UPC network.

The whole problem was caused by some mistakes in the configuration of the networking equipments belonging to UPC. The effect was that UPS started to announce in upstream (Internet) all the destinations (IP prefixes) belonging to RoEduNet and the traffic that should return from the Internet in RoEduNet was trying to pass through UPC. RoEduNet reported the problem to UPC, they opened a ticket but we don't have a plausible explanation for the incident yet. We assume that this was a regrettable human error and there was no intention to harm the traffic of the Romanian academic and research community. The issue has been solved by our network engineers by shutting down the peering connection between RoEduNet and UPC.

This incident shows how important is that each Internet Service Provider should be very careful with the configurations of own equipments not to harm others in the Internet. We still wait for official explanations from UPC Romania.