In my Amazon EC2 instance I am configuring the firewall to allow access from an IP address 1.2.3.4. The autocomplete feature is completing the addresses to 1.2.3.4/32. I’m not sure why, and I don’t see any mention of this in the AWS documentation.
I think that this might make sense if I were configuring an address of the type 1.2.3.0 to allow connections from the entire C block, but I am configuring a specific address. It this some usage of the CIDR notation that I am unfamiliar with? What is the autocomplete trying to suggest with this notation?
The /32 specifies a single address. A c block’s CIDR would be 1.2.3.0/24, which would include 254 usable addresses.
Here’s a nice little “cheat sheet” for CIDR stuff: http://www.oav.net/mirrors/cidr.html