Hey there. This is a bit blurry on whether it should be under Security or Networking, feel free to kick it elsewhere.
I'm currently setting up my firewall on a remote machine, meaning I'm SSHing to it.
What I want is to have a default deny rule, with an accept on SSH only. Since I am working remote, it would be preferable to set the accept rule before doing the default deny.
My question; if I set an accept on 22 before I do the default deny, will it work?
Guessing it'll be fine, but since I'm not really in a position to go to the machine, certainty is preferred.
Yes, that will work. You can always verify by doing "sudo iptables -v -L", before implementing the deny rule, which will show you how much traffic hit the existing rules.
I understand about wanting to be certain. Once I locked myself out of a router that was several states away.