I have to test an app which first downloads data, but then, can not communicate with the world for the duration of the test (so it doesn't gossip stuff).
There are ways to enforce this on the app, but I would like to be 100% and block all outgoing traffic.
If I set a security group on the cloud instance (aws ec2) which blocks all outgoing traffic from the instance, will that lock myself out?
The idea was that only port 22 incoming would be allowed for the duration of the test. But now I am concerned, doesn't an ssh connection originate on a random port on my machine, and if I block all outgoing traffic, won't that lock me out essentially?