udp packet not reach application

[Min Wang <ser.basis@gmail.com>]

HI

I have following issue ( kernel 3.2.28):

  a device sending udp traffic to UDP Port x -> my udp app ( listen on port x) 

at first, it was working. my app did get udp traffic. 

after a while, strace showed that my app stuck at recvfrom, no udp traffic

but tcpdump showed the udp traffic still coming.

Even if I restart my app, strace showed that no udp traffic at my app.

it seems the kernel did not deliver the udp packet to my app.

I have to restart NIC interface, then I could see udp traffic received at my app.

What could be wrong?

thanks.

min