In light of the problems experienced on Monday, TENET have indicated that they need to conduct some tests to determine why IPv6 is not correctly carried on the Grahamstown<->Bisho leg of SANReN. These tests are scheduled for 4PM today.
In theory the tests should not have any impact on Internet access. However, we should consider ourselves at risk of an IPv6 outage.
Should this happen, you will likely experience the outage as slow responses from IPv6-enabled web sites (which now includes many of the major content providers, such as Google, Facebook, etc), as your browser fails over from IPv6 to IPv4. You will not be able to reach any IPv6-only sites (such as ipv6.google.com).
The tests should be complete by 5.30PM.