tcpdump and route domains

0.0 is the internal interface between the switch plane and the control/management plane, so all traffic not accelerated by hardware should traverse this interface, regardless of route domain. However, tcpdump will discard packets if the rate is sufficiently high (and, in fact, the rate doesn't need to be all that high for it to do so). Are you seeing some of the expected packets, or none of them? If it is some, I'd guess the missing packets are a function of tcpdump's normal behavior.