DatagramSocket & ServerSocket via Server Help

Ok from what I understand:
DatagramSocket is UDP > I need to know it's function
ServerSocket might be TCP?

I found this at:
net.minecraft.network.rcon.RConThreadBase
net.minecraft.client.multiplayer.ThreadLanServerPing

I don't really know what the difference is nor why the server is running both when opening to lan. Also it appears my attempt to re-instantiate a lan port has failed on server side. I don't know what else I am missing here to change the port of the connection:
 

DedicatedServer server = (DedicatedServer) FMLCommonHandler.instance().getMinecraftServerInstance();
InetAddress inet = InetAddress.getByName(server.getServerHostname());
server.getNetworkSystem().addLanEndpoint(inet, port);
server.setServerPort(port);

Edited July 3, 20187 yr by jredfox