tcpdump -vvveni any port 53 and host 192.168.1.20 tcpdump: listening on any, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes 17:33:24.982171 In bc:5f:f4:83:b0:fe ethertype IPv4 (0x0800), length 87: (tos 0x0, ttl 128, id 11630, offset 0, flags [none], proto UDP (17), length 71) 192.168.1.20.64024 > 192.168.1.42.53: [udp sum ok] 1+ PTR? 42.1.168.192.in-addr.arpa. (43) 17:33:24.984073 Out b8:27:eb:d9:90:fe ethertype IPv4 (0x0800), length 110: (tos 0x0, ttl 64, id 37570, offset 0, flags [DF], proto UDP (17), length 94) 192.168.1.42.53 > 192.168.1.20.64024: [bad udp cksum 0x83ea -> 0x42a8!] 1* q: PTR? 42.1.168.192.in-addr.arpa. 1/0/0 42.1.168.192.in-addr.arpa. [0s] PTR northwind. (66) 17:33:24.985789 In bc:5f:f4:83:b0:fe ethertype IPv4 (0x0800), length 85: (tos 0x0, ttl 128, id 11632, offset 0, flags [none], proto UDP (17), length 69) 192.168.1.20.64025 > 192.168.1.42.53: [udp sum ok] 2+ A? steinweiler.local.local. (41) 17:33:24.986371 Out b8:27:eb:d9:90:fe ethertype IPv4 (0x0800), length 85: (tos 0x0, ttl 64, id 37571, offset 0, flags [DF], proto UDP (17), length 69) 192.168.1.42.53 > 192.168.1.20.64025: [bad udp cksum 0x83d1 -> 0x2225!] 2 NXDomain q: A? steinweiler.local.local. 0/0/0 (41) 17:33:24.987166 In bc:5f:f4:83:b0:fe ethertype IPv4 (0x0800), length 85: (tos 0x0, ttl 128, id 11633, offset 0, flags [none], proto UDP (17), length 69) 192.168.1.20.64026 > 192.168.1.42.53: [udp sum ok] 3+ AAAA? steinweiler.local.local. (41) 17:33:24.988666 Out b8:27:eb:d9:90:fe ethertype IPv4 (0x0800), length 85: (tos 0x0, ttl 64, id 37572, offset 0, flags [DF], proto UDP (17), length 69) 192.168.1.42.53 > 192.168.1.20.64026: [bad udp cksum 0x83d1 -> 0x0723!] 3 NXDomain q: AAAA? steinweiler.local.local. 0/0/0 (41) 17:33:24.989273 In bc:5f:f4:83:b0:fe ethertype IPv4 (0x0800), length 79: (tos 0x0, ttl 128, id 11635, offset 0, flags [none], proto UDP (17), length 63) 192.168.1.20.64027 > 192.168.1.42.53: [udp sum ok] 4+ A? steinweiler.local. (35) 17:33:24.990999 Out b8:27:eb:d9:90:fe ethertype IPv4 (0x0800), length 95: (tos 0x0, ttl 64, id 37573, offset 0, flags [DF], proto UDP (17), length 79) 192.168.1.42.53 > 192.168.1.20.64027: [bad udp cksum 0x83db -> 0xfcc8!] 4* q: A? steinweiler.local. 1/0/0 steinweiler.local. [0s] A 192.168.1.60 (51) 17:33:24.991756 In bc:5f:f4:83:b0:fe ethertype IPv4 (0x0800), length 79: (tos 0x0, ttl 128, id 11637, offset 0, flags [none], proto UDP (17), length 63) 192.168.1.20.64028 > 192.168.1.42.53: [udp sum ok] 5+ AAAA? steinweiler.local. (35) 17:33:24.994351 Out b8:27:eb:d9:90:fe ethertype IPv4 (0x0800), length 79: (tos 0x0, ttl 64, id 37574, offset 0, flags [DF], proto UDP (17), length 63) 192.168.1.42.53 > 192.168.1.20.64028: [bad udp cksum 0x83cb -> 0xdd69!] 5 q: AAAA? steinweiler.local. 0/0/0 (35)