At around 12:20 there was a problem on the LINX peering LAN (a peering exchange used by most of the UK internet). This affected one of our connections to LINX (in Telehouse) and caused routing to some destinations to break for a couple of minutes.
Service was stable by 12:35.
This was caused by some of the network switches in LINX's network rebooting. However, the cause of the rebooting is yet to be discovered. This affected many other internet providers connected to the LINX exchange point.