2011/03/23 - Unscheduled Internet Outage
For about the last hour South African universities (and probably other local ISPs) have experienced intermittent problems with international Internet access. These outages are the result of routing problems -- whilst we can reach the international Internet, we sometimes don't know how to route traffic to it nor does it know how to route traffic back to us. (Think of it as all the signposts randomly disappearing and re-appearing on the highways.)

The root cause of this appears to be high packet loss on SEACOM's network, and they're aware of the problem. We're told it should stabilise within the next few minutes.
This is the result of yet another failure on the terrestrial portion of SEACOM (actually SEA-ME-WE4) going through Egypt. This time around, protection circuits have kicked in and our traffic is flowing past the break on a different fibre.

The reason for the prolonged period of instability isn't yet known. It seems that many of the larger ISPs automatically failed onto the protection circuit within minutes whereas TENET was manually re-routed some 54 minutes later. TENET is following up with SEACOM to try and determine why this is the case.