BGP Router + Subnetting

Hi all,

I have a /24 that I am announcing with Vultr. I am using BIRD on a Vultr instance to route the entire /24 to my instance.

I can easily add IP's from that prefix to my Vultr instance and ping them remotely.

Now, if I wanted to begin subnetting my /24 into smaller slices, what is the recommend method to do so on Ubuntu 16.04? For instance, if I wanted a /29 from that /24 I would need a network IP, gateway and broadcast IP in that /29. What is the proper methodology to do assign this on Ubuntu or even pfSense?

Thanks!