5

My computer has only one network card. I have a program listening on one port. I intend to send one packet on the same machine, my program can receive the packet. I can't capture the packet by tcpdump on the machine which my program is running on.

If I send packet from another machine, tcpdump can capture the packet.

Hardy Feng
  • 459
  • 4
  • 13
  • Is my description not clear? My question is on hold state for a long time. I edited my question once, but it still keeps on hold state. – Hardy Feng Mar 04 '14 at 11:22

1 Answers1

8

If i understand you correctly, you send the packet from a machine to itself. If so, you need tcpdump on the loopback interface. e.g.

tcpdump -i lo
Fabio
  • 23,183
  • 12
  • 55
  • 64
Benav
  • 468
  • 5
  • 5