Public IP address range

Question

To setup SSH, Amazon asks us to

Enter your network's public IP address range

What is my public IP address range, and where can I find it?

Is this a range that is provided by my ISP?

Are there other computers in this range?

Is this a security measure that restricts attempts to connect from IPs outside to this range, but permits those inside?

I read this question which is very similar, but got accepted too soon with little insight regarding the question.

Finding my network's public IP address range

Answer 1

Your public IP address rage it is normally just a single IP address if you are a home user or a small company who is assigned only one address from the ISP.

To determine this address just go to https://ipv4.wtfismyip.com/text and in Amazon you would have to add a /32 netmask to specify that it's only this address.

The same thing can be easily accomplished by selecting "My IP" in the source tab for that security group.

In this case, nobody else can reach your servers on the SSH port.

If your IP address changes then the best bet is to go to the security group config everything it changes.

Companies are able to reserve more addresses from the ISP in order to use them for various things. For example, if they reserve 255 addresses then the range would be that address followed by a /24. That would allow every IP address reserved by those companies to go on the servers. Normally, that is not necessary even for companies who have more than one IP address.