HOw do I write a packet to the net and ensure that it will be written out "immediately"? I am having trouble with an ntp program (chrony) in that if I write out a packet onto the net, it may take up to a second before it actually gets sent. Thus the timestamp in the packet which is created just before the packet is sent is up to a second before the timestamp I get on the tcpdump output for that packet. -- this is only true sometimes. That this seems to be a problem in the network layer, is that if I run tcpdump with the -x ( which dumps the packet contents) that occasional one second delay disappears. HOw can I write that packet so that it will actually be sent immediately. Is there someway I can tell the system that this packet has priority? (Note I sometimes get the same problem on reading as well-- ie the system uses select to wait for the something to be read from the port, and at times I can get 10ms delays between when it arrives according to tcpdump and when the program actually reads the packet.)