Suppose I were to make these two rules:
“Allow TCP Out From IP [my computer] To IP Any Where Source Port Is Any And Destination Port is 80”
“Allow TCP In From IP [my computer] To IP Any Where Source Port Is Any And Destination Port is 80”
How are these two rules different? In each case the IP’s and Ports indicate traffic from my computer to a website or other HTTP server. What purpose does the “In” and “Out” serve that isn’t already established by the other 4 variables?
My point is: “from and to” and “source and destination” already imply direction. But if comodo is supplementing that with “in and out” does that mean comodo does not incorporate direction in the use of “from and to” and “source and destination”? Or is it just a layer of redundancy?
I actually prefer local and remote terminology, but think that adding the in and out helps prevent confusion like your second rule. TCP is a connection oriented protocol, and you can do 2 things: request a connection with another computer, which can either allow or block the connection; and when a connection request comes in from another computer you can either allow or block it. Once a connection is established, datagrams can go both ways, but the connector in a sense has control over the traffic with the connectee. So for out, you are always the source computer, for in, you are always the destination computer. You can’t make another computer take your TCP request as in rule two. A valid form of your second rule, used often, is “block tcp in from any to my computer from port 80 to any”. It doesn’t do much to try to block inputs to your port 80 unless you are an http server, but sometimes the http servers send a bunch of trash to you.
Now if you allow tcp in/out, things get a little confused again-thus my preference for local and remote. And just grit your teeth when allowing TCP/UDP and remember that ports only apply to TCP. But you get used to the Comodo syntax after a bit.