subnet - IPv4/IPv6 subnet calculator

Usage:
  curl https://ttykit.com/subnet/<address>/<prefix>
  curl https://ttykit.com/subnet/<address>/<netmask>          (IPv4 only)
  curl "https://ttykit.com/subnet/<address>/<prefix>?split=<prefix>"

Examples:
  curl https://ttykit.com/subnet/192.168.1.10/24
  curl https://ttykit.com/subnet/10.0.0.0/255.255.248.0
  curl https://ttykit.com/subnet/2001:db8::/32
  curl "https://ttykit.com/subnet/10.0.0.0/22?split=24"

split=<prefix> lists the smaller subnets instead (one per line, max 256).