I was surprised to find that wxforum.net (and northamericanweather.net) not accessable (via http/https/ftp/ssh) for a time this morning.
Called 1and1 tech support and when they answered and checked, it was working. D'Oh.
Logged in via SSH and ran top.
top - 11:39:36 up 37 days, 5:11, 1 user, load average: 11.63, 188.94, 286.43
so there was likely a runaway process of some kind chewing up all the cycles. Load average 286 is enormous and could explain why connections were failing.
Oh well, they (and I) will continue to monitor..