Specifying Public IP Address in “Port Forwarding rule”

Question

This is probably a super easy question but I can't find the answer online. I have an actiontec router, and when I'm under "Add Port Forwarding Rule", I have one checkbox that says "Specify Public IP Address". If I check this box, I'm given an option to include a Public IP Address.

What does this address mean? If I check the box and add an address say (55.555.555.555) for example, then will this rule only be applied when the incoming computer's address has an ip of 55.555.555.555?

Thanks.

Answer 1

It's only useful if you have more than 1 public IP. Say you have 1.1.1.1 and 1.1.1.2 as your public IPs, you can then specify that if someone hits port 22 on 1.1.1.1 it will be forwarded to 192.168.0.1 and hitting port 22 on 1.1.1.2 wont (for example).