Restrict IP access to Port 443

Question

How can restrict access to port 443 on my Debian server. I have an application running on that particular port that I'd like to restrict access to to only one IP: my own.

Answer 1

sudo iptables -A INPUT -p tcp --dport 443 -s ! 123.123.123.123 -j DROP

That should do it. Replace 123.123.123.123 with your IP. This basically adds a rule which will drop all connections not from your IP :)