noticeboard.ru.ac.za

2011/08/25 - Intermittent International Internet Access
Access to Internet is currently somewhat erratic and has been for most of the morning. The main problem is that international connectivity is sporadic, but this is also having an effect on our ability to reach some local sites (notably those with DNS hosted outside the country).

You will likely experience this outage as an ERR_DNS_FAIL or ERR_CONNECT_FAIL error when trying to access websites hosted outside South Africa (even those ending in .za). When accessing secure (https://) web sites, your browser may report that the connection has timed out or the site is unreachable.

This is caused by a faulty interface on TENET's router in Durban. TENET are aware of the problem, and are currently trying to source spares. Their service desk was unable to give me a time-to-repair.
The problem is that the line cards that provides the interfaces that connects the Durban router to the rest of the network keep rebooting. They seem to be doing this at increasing intervals, which means that international connectivity is likely to get increasingly sporadic and ultimately fail completely. In other words, it'll get worse before it gets better.

TENET are waiting for a courier to deliver replacement line cards. They've tentatively scheduled emergency maintenance for tonight to replace the card. However, they've indicated that they're likely to replace the card as soon as it arrives (preferably well before this evening). They're hopeful this will happen within the next couple of hours.
post.5532588