A have two card, installed A virtual machine at the same time, so the virtual machine also have two card, IP network segment 192.168.22 respectively. The X and y 192.168.21. X, ping, each in their A, B is common, but C (192.168.22.21), B (192.168.21.13),

Use of multicast tools now, in the B A multicast signals, through A virtual machine, C is to be able to know, but not A, in turn, use Tcpdump caught, found in C signal multicast, virtual machine card 0, IP (192.168.22. X) can crawl to the package, but the virtual network adapter 1, nic IP for 192.168.21. (X) is not captured, whether between virtual network card has A problem, seek counsel