Like I said, it depends on how you're already searching, and how the network is set up.
Obtaining the subnet mask will allow you to get the broadcast address for your current subnet. If you just want to try it out on your current network, it's fairly easy because if you know the subnet address is 255.255.0.0 then the associated broadcast IP is going to be x.x.255.255, where the two x's represent the octets in your ip address (so if your IP address is 192.168.17.22, and your subnet mask is 255.255.0.0 then the broadcast address would be 192.168.255.255).
Obtaining the subnet mask will allow you to get the broadcast address for your current subnet. If you just want to try it out on your current network, it's fairly easy because if you know the subnet address is 255.255.0.0 then the associated broadcast IP is going to be x.x.255.255, where the two x's represent the octets in your ip address (so if your IP address is 192.168.17.22, and your subnet mask is 255.255.0.0 then the broadcast address would be 192.168.255.255).