title: RecvFrom() returns packet larger than sender NIC MTU
body: <p>I have proprietary application sending out multicast packet to the network. It is running on the linux with NIC MTU 1500.</p>
  
  <p>And then I write a simple java program to using MulticastSocket class to receive message. I found it is DatagramPacket size is ~7900. The receiver program is running on the linux with NIC MTU 1500.</p>
  
  <p>I rewrite the program in C and using recvfrom() call, but the result is the same.</p>
  
  <p>I don't understand why? is it packet size  limited by NIC MTU? or can it be override by the program?</p>