Network works for UdpNtpClient and WevServer, but not for UdpSendReceiveString

Is there something special I have to do to make it monitor the broadcast address? The ip address of the arduino is 2.111.10.121 (as dictated by the spec for the protocol I am using), the subnet mask is 255.0.0.0, and the broadcast address I'm using on my computer is 2.255.255.255. This all appears to be right, but