We have just experienced a network outage which caused connection issues to our hosting servers. Connectivity now appears to be restored. The problem was caused by the routing issue within the network above us. Their engineers are currently investigating the cause.
Swift Internet NOC 
Our network supplier has updated to advise that the cause of the network outage 19/12 was an ARP storm, not a hardware failure.
They report that an ARP storm occurred, which consequently prevented traffic from routing through the core router. Whilst there is a level of protection against packet storm incidents of this type, it was not triggered in this instance, hence they are now currently reviewing the storm control levels that are set to prevent the possibility of a re-occurrence.