Odd one, I briefly either lost IPv6, or lost the A&A gateway. Things seemed to lock up, and when I tried a basic ping this is what I got ...
C:\Windows\system32>ping ntp.plus.net
Pinging ntp.plus.net [212.159.13.49] with 32 bytes of data:
Reply from 212.159.13.49: bytes=32 time=27ms TTL=57
Reply from 212.159.13.49: bytes=32 time=23ms TTL=57
Reply from 212.159.13.49: bytes=32 time=24ms TTL=57
Ping statistics for 212.159.13.49:
Packets: Sent = 3, Received = 3, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 23ms, Maximum = 27ms, Average = 24ms
Couple of minutes later it's back.
C:\Windows\system32>ping ntp.plus.net
Pinging ntp.plus.net [2001:8b0:6464:0:666:616:d49f:d32] with 32 bytes of data:
Reply from 2001:8b0:6464:0:666:616:d49f:d32: time=141ms
Reply from 2001:8b0:6464:0:666:616:d49f:d32: time=120ms
Reply from 2001:8b0:6464:0:666:616:d49f:d32: time=170ms
Reply from 2001:8b0:6464:0:666:616:d49f:d32: time=194ms
Ping statistics for 2001:8b0:6464:0:666:616:d49f:d32:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 120ms, Maximum = 194ms, Average = 156ms
C:\Windows\system32>