(whoops - Movable Type 4 decided to mess up the permalink from the index page on this entry earlier; it should be fixed now. Darn bugs in run-periodic-tasks, grrh).
One of the NTP Pool server operators emailed recently and told that his server was unavailable for a few hours because he had changed some firewall rules remotely and managed to lock everyone out. Oops!
There's an easy way to do safe remote firewall changes.
He should have used the at daemon to automatically
recover! If you don't have a console server then you absolutely must get in the
habit of using it before doing anything that can lock you out of
your server.
The basic concept is to setup something that in say 5 minutes will undo whatever you're about to do. So if you are messing with the …
[Read more]