We ran ping request from pinger.slac.stanford.edu to www.cern.ch and watched the traffic with tcpdump. It is seen that each request results in 3 responses from webr7.cern.ch (137.138.144.168).
56cottrell@pinger:~$sudo tcpdump 'icmp' tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes 01:47:40.544350 IP pinger.slac.stanford.edu > webr7.cern.ch: ICMP echo request, id 8750, seq 42, length 64 01:47:40.720681 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 42, length 64 01:47:40.720701 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 42, length 64 01:47:40.720707 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 42, length 64 01:47:41.545378 IP pinger.slac.stanford.edu > webr7.cern.ch: ICMP echo request, id 8750, seq 43, length 64 01:47:41.722537 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 43, length 64 01:47:41.722557 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 43, length 64 01:47:41.722780 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 43, length 64 01:47:42.546381 IP pinger.slac.stanford.edu > webr7.cern.ch: ICMP echo request, id 8750, seq 44, length 64 01:47:42.722109 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 44, length 64 01:47:42.722128 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 44, length 64 01:47:42.722134 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 44, length 64 01:47:43.548220 IP pinger.slac.stanford.edu > webr7.cern.ch: ICMP echo request, id 8750, seq 45, length 64 01:47:43.724698 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 45, length 64 01:47:43.724821 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 45, length 64 01:47:43.724832 IP webr7.cern.ch > pinger.slac.stanford.edu: ICMP echo reply, id 8750, seq 45, length 64 ^C 16 packets captured 137 packets received by filter 37 packets dropped by kernel
Translating the foreign IP name (www.cern.ch) to its IP address.
64cottrell@pinger:~$sudo tcpdump -f 'icmp' tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes 02:03:03.187377 IP pinger.slac.stanford.edu > 137.138.144.168: ICMP echo request, id 29278, seq 12, length 64 02:03:03.365112 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 12, length 64 02:03:03.365154 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 12, length 64 02:03:03.365167 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 12, length 64 02:03:03.393464 IP 132.249.193.32 > pinger.slac.stanford.edu: ICMP echo request, id 63805, seq 29696, length 64 02:03:03.393511 IP pinger.slac.stanford.edu > 132.249.193.32: ICMP echo reply, id 63805, seq 29696, length 64 02:03:04.188377 IP pinger.slac.stanford.edu > 137.138.144.168: ICMP echo request, id 29278, seq 13, length 64 02:03:04.365561 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 13, length 64 02:03:04.365581 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 13, length 64 02:03:04.365690 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 13, length 64 02:03:05.189376 IP pinger.slac.stanford.edu > 137.138.144.168: ICMP echo request, id 29278, seq 14, length 64 02:03:05.272524 IP 132.249.193.32 > pinger.slac.stanford.edu: ICMP echo request, id 63805, seq 29696, length 64 02:03:05.272548 IP pinger.slac.stanford.edu > 132.249.193.32: ICMP echo reply, id 63805, seq 29696, length 64 02:03:05.367585 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 14, length 64 02:03:05.367606 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 14, length 64 02:03:05.367611 IP 137.138.144.168 > pinger.slac.stanford.edu: ICMP echo reply, id 29278, seq 14, length 64 ^C 16 packets captured 145 packets received by filter 37 packets dropped by kernel