running tcpreplay with docker and boot2docker

Question

I'm working on a netflow logger and I want to setup some automated performance testing. I want to take my testing pcap and replay it to my program from within a docker image running under boot2docker. The networking side of this is stumping me.

I can access my desktop (the machine hosting the boot2docker vm) from within the docker image running under boot2docker (scp/ssh/netcat all seem to work as expected). However, when I run tcpreplay on my pcap from within the docker image I never see the traffic on my desktop.

What I've tried:

• rewrite the srcip in the pcap to be the srcip of the docker host
• tcpdump piped through netcat (netflow is UDP so I don't really care about the connection setup) The traffic makes it but my program gets some exceptions and dies. This doesn't surprise me, but it does indicate that I can get the traffic out of the docker vm and into my program.
• I can successfully tcpreplay the pcap to my program from within a normal debian vm

Any ideas on what I need to do to get tcpreplay to send my pcap to my desktop?

Answer 1

Try change the destination MAC addr to that of docker0, which is the default VM running. This works for me.