Code:
tcpdump: listening on nfe0, link-type EN10MB (Ethernet), capture size 96 bytes
06:20:36.618694 IP (tos 0x0, ttl 112, id 64720, offset 0, flags [none], proto UDP (17), length 131) 195.189.97.122.57944 > 207.6.123.87.45853: UDP, length 103
06:20:37.435792 IP (tos 0x0, ttl 64, id 1928, offset 0, flags [none], proto UDP (17), length 71) 207.6.123.87.58444 > 75.154.133.68.domain: [udp sum ok] 32387+ PTR? 87.123.6.207.in-addr.arpa. (43)
06:20:37.481066 IP (tos 0x0, ttl 247, id 27864, offset 0, flags [DF], proto UDP (17), length 201) 75.154.133.68.domain > 207.6.123.87.58444: 32387 q: PTR? 87.123.6.207.in-addr.arpa. 1/2/2 87.123.6.207.in-addr.arpa.[|domain]
06:20:38.213907 IP (tos 0x0, ttl 107, id 58831, offset 0, flags [none], proto UDP (17), length 126) 78.131.211.178.27370 > 207.6.123.87.45853: UDP, length 98
06:20:40.509953 IP (tos 0x0, ttl 116, id 59345, offset 0, flags [none], proto UDP (17), length 90) 222.83.215.126.16001 > 207.6.123.87.45853: UDP, length 62
06:20:40.799499 IP (tos 0x0, ttl 114, id 9179, offset 0, flags [none], proto UDP (17), length 126) 210.253.80.120.13899 > 207.6.123.87.45853: UDP, length 98
06:20:41.177728 IP (tos 0x0, ttl 113, id 5882, offset 0, flags [none], proto UDP (17), length 126) 60.53.86.102.26535 > 207.6.123.87.45853: UDP, length 98
06:20:41.317674 IP (tos 0x0, ttl 116, id 59410, offset 0, flags [none], proto UDP (17), length 90) 222.83.215.126.16001 > 207.6.123.87.45853: UDP, length 62
06:20:42.439868 IP (tos 0x0, ttl 64, id 1929, offset 0, flags [none], proto UDP (17), length 71) 207.6.123.87.50541 > 75.154.133.100.domain: [udp sum ok] 32387+ PTR? 87.123.6.207.in-addr.arpa. (43)
06:20:42.498969 IP (tos 0x0, ttl 246, id 45275, offset 0, flags [DF], proto UDP (17), length 201) 75.154.133.100.domain > 207.6.123.87.50541: 32387 q: PTR? 87.123.6.207.in-addr.arpa. 1/2/2 87.123.6.207.in-addr.arpa.[|domain]
06:20:44.442275 IP (tos 0x0, ttl 64, id 1930, offset 0, flags [none], proto UDP (17), length 71) 207.6.123.87.58444 > 75.154.133.68.domain: [udp sum ok] 32387+ PTR? 87.123.6.207.in-addr.arpa. (43)
06:20:44.488482 IP (tos 0x0, ttl 247, id 31714, offset 0, flags [DF], proto UDP (17), length 201) 75.154.133.68.domain > 207.6.123.87.58444: 32387 q: PTR? 87.123.6.207.in-addr.arpa. 1/2/2 87.123.6.207.in-addr.arpa.[|domain]