pingでDUP!って出る件
macからRaspberry PI(FreeBSD 12)にpingする。
$ ping -c4 192.168.1.9 PING 192.168.1.9 (192.168.1.9): 56 data bytes 64 bytes from 192.168.1.9: icmp_seq=0 ttl=64 time=7.090 ms 64 bytes from 192.168.1.9: icmp_seq=0 ttl=64 time=7.110 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=0 ttl=64 time=7.113 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=0 ttl=64 time=7.116 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=0 ttl=64 time=7.119 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=1 ttl=64 time=12.260 ms 64 bytes from 192.168.1.9: icmp_seq=1 ttl=64 time=12.514 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=1 ttl=64 time=12.521 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=1 ttl=64 time=12.523 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=1 ttl=64 time=12.525 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=2 ttl=64 time=7.955 ms 64 bytes from 192.168.1.9: icmp_seq=2 ttl=64 time=7.967 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=2 ttl=64 time=7.970 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=2 ttl=64 time=7.976 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=2 ttl=64 time=7.978 ms (DUP!) 64 bytes from 192.168.1.9: icmp_seq=3 ttl=64 time=5.988 ms --- 192.168.1.9 ping statistics --- 4 packets transmitted, 4 packets received, +12 duplicates, 0.0% packet loss round-trip min/avg/max/stddev = 5.988/8.983/12.525/2.404 ms
$ sudo tcpdump -i en0 -p -n icmp tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on en0, link-type EN10MB (Ethernet), capture size 262144 bytes 22:18:20.565875 IP 192.168.1.12 > 192.168.1.9: ICMP echo request, id 17157, seq 0, length 64 22:18:20.572882 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64 22:18:20.572895 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64 22:18:20.572898 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64 22:18:20.572900 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64 22:18:20.572902 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64
Raspberry PIのtcmdump
# tcpdump -i ue0 -p -n icmp tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on ue0, link-type EN10MB (Ethernet), capture size 262144 bytes 22:18:20.570596 IP 192.168.1.12 > 192.168.1.9: ICMP echo request, id 17157, seq 0, length 64 22:18:20.572422 IP 192.168.1.12 > 192.168.1.9: ICMP echo request, id 17157, seq 0, length 64 22:18:20.572991 IP 192.168.1.12 > 192.168.1.9: ICMP echo request, id 17157, seq 0, length 64 22:18:20.573462 IP 192.168.1.12 > 192.168.1.9: ICMP echo request, id 17157, seq 0, length 64 22:18:20.573923 IP 192.168.1.12 > 192.168.1.9: ICMP echo request, id 17157, seq 0, length 64 22:18:20.574099 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64 22:18:20.574122 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64 22:18:20.574133 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64 22:18:20.574141 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64 22:18:20.574149 IP 192.168.1.9 > 192.168.1.12: ICMP echo reply, id 17157, seq 0, length 64
