Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I use the following in order to transfer bigfile (11GB):

cat bigfile | pv -L 11m | nc -u 3333

After 1.6GB the client stop to transfer (in the target machine i dont see packets )

This is not lost packet problem, because the PV is on the cat in the client side.

Both computer running Ubuntu. For the first 1.6GB i see in wireshark on the target machine that it get the packets, but after 1.6GB the PV on the client side dosnt show any progress and wireshark on target machine show that no packets arrived. If i CTRL-C the sender and start it again i see that packets arrived, so i dont think it server problem (netcat run on the server like this - nc -u -l 3333 > bigfile).

Any idea why?

share|improve this question
This is by design: UDP does not guarantee delivery of packets. You may lose parts of your file, some parts might be duplicated, and other may be reodered. If you don't want this, don't use UDP. – BatchyX Nov 4 '12 at 12:52
The PV is on the cat. the client stop send packets after 1.6GB – Avihai Marchiano Nov 4 '12 at 12:55
Which OS? Network layout (both computers on same subnet)? How did you check that no packets arrive at the target - with a sniffer? Do you see the packets for the first 1.6GB? – Yaniv Aknin Nov 4 '12 at 13:51
@YanivAknin i added this data to the question. Thank you – Avihai Marchiano Nov 4 '12 at 17:44

On the client side, try dd if=file bs=1M | pv -L 11m | nc -u 3333 instead. I wonder if it's something to do with how much data cat is putting into the pipe?

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.