I really wish my firewall supported this: A way of doing a “secret knock” on a firewall to get access to closed ports. I know I don’t like to keep ports open all the time, but there are times where I wish certain ones were open. So for example, if I wanted to get access to the closed SSH port (22), I could make connection attempts to closed ports 1026, 1027, 1029, 1034, 1026, 1044, and 1035 (in that order) within 5 seconds, it would then open up port 22 for a connection for 10 seconds, then shut it down if the port wasn’t accessed. Link via BB.