We pinged www.lonab.bf once per second using the standard Linux ping. At the same time we used tcpdump to capture and display the ICMP packets.

pings

The relevant section og the ping output is shown below, note the seq numbers:

64 bytes from 206.82.130.77: icmp_seq=111 ttl=44 time=270 ms
64 bytes from 206.82.130.77: icmp_seq=112 ttl=44 time=273 ms
64 bytes from 206.82.130.77: icmp_seq=113 ttl=44 time=269 ms
64 bytes from 206.82.130.77: icmp_seq=114 ttl=44 time=273 ms
64 bytes from 206.82.130.77: icmp_seq=115 ttl=44 time=271 ms
64 bytes from 206.82.130.77: icmp_seq=116 ttl=44 time=275 ms
64 bytes from 206.82.130.77: icmp_seq=117 ttl=44 time=272 ms
64 bytes from 206.82.130.77: icmp_seq=118 ttl=44 time=271 ms
64 bytes from 206.82.130.77: icmp_seq=119 ttl=44 time=275 ms
64 bytes from 206.82.130.77: icmp_seq=119 ttl=44 time=275 ms (DUP!)
64 bytes from 206.82.130.77: icmp_seq=119 ttl=44 time=275 ms (DUP!)
64 bytes from 206.82.130.77: icmp_seq=119 ttl=44 time=275 ms (DUP!)
64 bytes from 206.82.130.77: icmp_seq=119 ttl=44 time=276 ms (DUP!)
64 bytes from 206.82.130.77: icmp_seq=120 ttl=44 time=272 ms
64 bytes from 206.82.130.77: icmp_seq=121 ttl=44 time=271 ms
64 bytes from 206.82.130.77: icmp_seq=122 ttl=44 time=267 ms
64 bytes from 206.82.130.77: icmp_seq=123 ttl=44 time=276 ms

tcpdump

The equivalent packet trace from tcpdump is shown below. Note there is one seq 119 packet from pinger.slac.stanford.edu to 206.82.130.77 but 5 responses with the sequence number 119 from 206.82.130.77.

11:00:31.238378 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 111, length 64
11:00:31.508471 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 111, length 64
11:00:32.239483 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 112, length 64
11:00:32.512677 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 112, length 64
11:00:33.240796 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 113, length 64
11:00:33.510159 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 113, length 64
11:00:34.242179 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 114, length 64
11:00:34.516034 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 114, length 64
11:00:35.242383 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 115, length 64
11:00:35.513823 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 115, length 64
11:00:36.243391 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 116, length 64
11:00:36.518896 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 116, length 64
11:00:37.244385 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 117, length 64
11:00:37.516604 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 117, length 64
11:00:38.245381 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 118, length 64
11:00:38.517273 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 118, length 64
11:00:39.246214 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 119, length 64
11:00:39.522121 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 119, length 64
11:00:39.522151 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 119, length 64
11:00:39.522157 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 119, length 64
11:00:39.522163 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 119, length 64
11:00:39.522232 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 119, length 64
11:00:40.247245 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 120, length 64
11:00:40.519875 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 120, length 64
11:00:41.248386 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 121, length 64
11:00:41.520310 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 121, length 64
11:00:42.249263 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 122, length 64
11:00:42.252883 IP noc-prod-smokeping-1.ucsc.edu > pinger.slac.stanford.edu: ICMP echo request, id 2125, seq 40448, length 64
11:00:42.252939 IP pinger.slac.stanford.edu > noc-prod-smokeping-1.ucsc.edu: ICMP echo reply, id 2125, seq 40448, length 64
11:00:42.516688 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 122, length 64
11:00:43.250378 IP pinger.slac.stanford.edu > 206.82.130.77: ICMP echo request, id 10332, seq 123, length 64
11:00:43.526774 IP 206.82.130.77 > pinger.slac.stanford.edu: ICMP echo reply, id 10332, seq 123, length 64
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