IP.Mask in Go
Mask returns the result of masking the IP address ip with mask.
package main
import (
"fmt"
"net"
)
func main() {
ipv4Addr := net.ParseIP("192.0.2.1")
// This mask corresponds to a /24 subnet for IPv4.
ipv4Mask := net.CIDRMask(24, 32)
fmt.Println(ipv4Addr.Mask(ipv4Mask))
ipv6Addr := net.ParseIP("2001:db8:a0b:12f0::1")
// This mask corresponds to a /32 subnet for IPv6.
ipv6Mask := net.CIDRMask(32, 128)
fmt.Println(ipv6Addr.Mask(ipv6Mask))
}