Comment 4 for bug 1012144

bug #956474 shows the opposite problem - duplicate packages when pinging between floating IPs

The fix for bug #933460 should have made this work. Could you try running:

  $> for iii in $(ls -d /sys/class/net/*); do echo -n "$iii "; cat $iii/brport/hairpin_mode 2>/dev/null || echo; done

and paste the output?

You could also try the fix for bug #1040537, but that looks unrelated.