使用dig +trace命令查看dns解析流程
root@pve:~# dig +trace www.baidu.com ; <<>> DiG 9.16.22-Debian <<>> +trace www.baidu.com ;; global options: +cmd . 682 IN NS i.root-servers.net. . 682 IN NS k.root-servers.net. . 682 IN NS e.root-servers.net. . 682 IN NS h.root-servers.net. . 682 IN NS c.root-servers.net. . 682 IN NS l.root-servers.net. . 682 IN NS g.root-servers.net. . 682 IN NS a.root-servers.net. . 682 IN NS d.root-servers.net. . 682 IN NS m.root-servers.net. . 682 IN NS j.root-servers.net. . 682 IN NS b.root-servers.net. . 682 IN NS f.root-servers.net. . 682 IN NS k.root-servers.net. . 682 IN NS e.root-servers.net. . 682 IN NS h.root-servers.net. . 682 IN NS c.root-servers.net. . 682 IN NS l.root-servers.net. . 682 IN NS g.root-servers.net. . 682 IN NS a.root-servers.net. . 682 IN NS d.root-servers.net. . 682 IN NS m.root-servers.net. . 682 IN NS j.root-servers.net. . 682 IN NS b.root-servers.net. . 682 IN NS f.root-servers.net. . 682 IN NS i.root-servers.net. ;; Received 397 bytes from 192.168.130.1#53(192.168.130.1) in 4 ms com. 172800 IN NS a.gtld-servers.net. com. 172800 IN NS b.gtld-servers.net. com. 172800 IN NS c.gtld-servers.net. com. 172800 IN NS d.gtld-servers.net. com. 172800 IN NS e.gtld-servers.net. com. 172800 IN NS f.gtld-servers.net. com. 172800 IN NS g.gtld-servers.net. com. 172800 IN NS h.gtld-servers.net. com. 172800 IN NS i.gtld-servers.net. com. 172800 IN NS j.gtld-servers.net. com. 172800 IN NS k.gtld-servers.net. com. 172800 IN NS l.gtld-servers.net. com. 172800 IN NS m.gtld-servers.net. com. 86400 IN DS 30909 8 2 E2D3C916F6DEEAC73294E8268FB5885044A833FC5459588F4A9184CF C41A5766 com. 86400 IN RRSIG DS 8 1 86400 20220309050000 20220224040000 9799 . kbgM3AOza9UruhoSmXOJhSO5mrnB77n7arlnyHgJAP/6uYwwysafqjSp zHaBtewDnsYop7a5B8CfoLI+oE5LesTr/9hkffCAo7og5fd4ZsuvTiZT WIiYGK7IjyokFZp+BiNvWJmKh/Ob4QBJaJpSvJezgshBcSIT6y/orRDV pVnKdMazmrXYEuEdLzm+bPNW/ltW+8OYLYWkczN4dMvJS5M8Hn3d9dY3 PESsA+uXpwS/HTCfqzs0ywdeq+qXFHTa8dVR4/CKzsVyuQtR4QUhi+gz /nO5+HBSmSFHWRWsSJHDxzOnFddchDvKKHnFVhYtttVaLEnC7zkNXkLz eApoKg== ;; Received 1173 bytes from 198.41.0.4#53(a.root-servers.net) in 204 ms baidu.com. 172800 IN NS ns2.baidu.com. baidu.com. 172800 IN NS ns3.baidu.com. baidu.com. 172800 IN NS ns4.baidu.com. baidu.com. 172800 IN NS ns1.baidu.com. baidu.com. 172800 IN NS ns7.baidu.com. CK0POJMG874LJREF7EFN8430QVIT8BSM.com. 86400 IN NSEC3 1 1 0 - CK0Q1GIN43N1ARRC9OSM6QPQR81H5M9A NS SOA RRSIG DNSKEY NSEC3PARAM CK0POJMG874LJREF7EFN8430QVIT8BSM.com. 86400 IN RRSIG NSEC3 8 2 86400 20220228052341 20220221041341 38535 com. kHFbWrb9PnX4/Qdvm6KX6kZUUqqlhn6LufPTw8Tiqc9NJulWenzJi/a0 Xvw4raIVEPPxhWnmFpwltc9mZMW/mVsXyr4xaXg2y1kBQASpRzLwf1Zf 4oaLmc6t6relhsVL+XLwR0DE4svATQNv+elAr84MM1LIwR4I+HwWn51z rL5Hs8ivlpVosi3AtfAb7sEkRNkxeYyk+IQlLYlwugqtIQ== HPVU6NQB275TGI2CDHPDMVDOJC9LNG86.com. 86400 IN NSEC3 1 1 0 - HPVV8SARM2LDLRBTVC5EP1CUB1EF7LOP NS DS RRSIG HPVU6NQB275TGI2CDHPDMVDOJC9LNG86.com. 86400 IN RRSIG NSEC3 8 2 86400 20220301053212 20220222042212 38535 com. LForyUDwHGyp5vqjl/7DGFuDb4SX1WlvvN9fDL0Vyw66Vl3hxMzdOkoh jYcrOH5hxBrKV3+o0heJirGZAc2SOvBlpunznZ8qxUqNCSi1Kwlts22K ys7RloXEUJF7aov8RMlTKMioT979MJWydR3WN+wVDpqcYgigHHfquvOc TasfnkFpbJ8FepKqPaSlALxiJxRqtA4NautGBV3FRlqJ1A== ;; Received 817 bytes from 192.43.172.30#53(i.gtld-servers.net) in 212 ms www.baidu.com. 1200 IN CNAME www.a.shifen.com. a.shifen.com. 1200 IN NS ns2.a.shifen.com. a.shifen.com. 1200 IN NS ns5.a.shifen.com. a.shifen.com. 1200 IN NS ns1.a.shifen.com. a.shifen.com. 1200 IN NS ns4.a.shifen.com. a.shifen.com. 1200 IN NS ns3.a.shifen.com. ;; Received 295 bytes from 14.215.178.80#53(ns4.baidu.com) in 28 ms