Windows can bind to any port number. OSX, like most Nix, will prevent a process binding to ports <1024, unless run with superuser access permissions. That is not your problem though, as 1434 is > 1024.
I think it is far more likely that you're failing to bind to 1434 because there is another process already bound to 1434; SQLServer or one of it's components, for instance.
What's not explicitly mentioned in the RS documentation, is that you don't need to bind a socket to 1434 to target 1434.
UDPSocket1.Port = 30000 //or any other ephemeral port
If UDPSocket1.IsConnected Then
Dim dg as new Datagram
dg.Address = UDPSocket1.BroadcastAddress
dg.Port = 1434
dg.Data = chr(2)