Program that sends IP telegram

i have a gateway and a laptop and they are both on the same network.
In order to send commands to the gateway, i want to use my laptop to send ip messages to the gateway.
Therefore i need a software that allows me to send ip messages/telegrams.
Does anyone know if i can download this software from somewhere?
Or if you are willing to share any self created program, that would be great!!

thank you very much

What kind of commands does the gateway have to use? Can you telnet, ftp or http to it?