ubuntu@ubuntu:~$ ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=55 time=32.8 ms
^C
--- 8.8.8.8 ping statistics ---
6 packets transmitted, 1 received, 83% packet loss, time 5081ms
rtt min/avg/max/mdev = 32.875/32.875/32.875/0.000 ms

root@core1:~ # tcpdump -i gre0 icmp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on gre0, link-type NULL (BSD loopback), capture size 262144 bytes
12:26:35.361531 IP 176.9.x.x > google-public-dns-a.google.com: ICMP echo request, id 1784, seq 1, length 64
12:26:35.393693 IP google-public-dns-a.google.com > 176.9.x.x: ICMP echo reply, id 1784, seq 1, length 64
12:26:36.362530 IP 192.168.254.106 > google-public-dns-a.google.com: ICMP echo request, id 1784, seq 2, length 64
12:26:37.371299 IP 192.168.254.106 > google-public-dns-a.google.com: ICMP echo request, id 1784, seq 3, length 64
12:26:38.395302 IP 192.168.254.106 > google-public-dns-a.google.com: ICMP echo request, id 1784, seq 4, length 64
12:26:39.419105 IP 192.168.254.106 > google-public-dns-a.google.com: ICMP echo request, id 1784, seq 5, length 64
12:26:40.443423 IP 192.168.254.106 > google-public-dns-a.google.com: ICMP echo request, id 1784, seq 6, length 64