The present invention relates to method and apparatus for receivability test and reachability test of explicit multicast packet. In one embodiment, the xcast receivability test comprises i) at a sender end, sending a receivability probe packet to a receiver end, ii) at the receiver end, receiving the receivability probe packet, iii) generating an ICMP error message-Destination Unreachable, iv) sending the ICMP error message-Destination Unreachable to sender end, v) at the sender end, receiving the ICMP error message-Destination Unreachable and vi) analyzing the ICMP error message-Destination Unreachable.