My ISP is currently working on resolving some network problems that are the cause of the current unavailability of the server. According to them the problem should be resolved within an hour, which I’m hopeful will be true. They are also suggesting that this might solve the intermittent issues with network unavailability, which have been occurring (albeit infrequently) over the last month or so.
Update: The network connection was not restored until this morning, and so was a rather extensive breakdown of services. At least someone else was to blame this time :-)