Now has two hosts in a local area network (LAN) P1, P2, their Intranet address 10.0.0.110 and 10.0.0.78 respectively, into a NAT mapping outside the web address is respectively addr1/port1, addr2/port2, now want to make them by running the program (P1 and P2 in the program are the same) to each other outside the web address and port to receive udp messages by wireshark caught in P2, detection unexpectedly can't catch a udp packet, if is a problem of routing, estimation is caused by those problems?