参考链接

DNS解析原理#

原理图示#

简述#

首先一个完整的域名是这样子的www.bilibili.com.，要注意后面是有一个点，这个点表示根，所有顶级域名(.com、.cn、.org)由于根进行管理。域名的解析过程也会按照以下的结构进行查找，每个节点都有对应的域名服务器。
用CMD演示解析过程#

当输入命令nslookup时，会跳出>这样的命令模式，输入set type=ns，然后再输入根域名也就是.会显示所有的解析类型
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admin@admin:~$ nslookup
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> set type=ns
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> .
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Server:         172.29.240.1
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Address:        172.29.240.1#53
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Non-authoritative answer:
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    nameserver = m.root-servers.net.
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    nameserver = b.root-servers.net.
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    nameserver = c.root-servers.net.
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    nameserver = d.root-servers.net.
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    nameserver = e.root-servers.net.
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    nameserver = f.root-servers.net.
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    nameserver = g.root-servers.net.
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    nameserver = h.root-servers.net.
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    nameserver = a.root-servers.net.
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    nameserver = i.root-servers.net.
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    nameserver = j.root-servers.net.
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    nameserver = k.root-servers.net.
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    nameserver = l.root-servers.net.
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Authoritative answers can be found from:
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> set type=b
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unknown query type: b
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> set type=a
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> b.root-servers.net.
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Server:         172.29.240.1
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Address:        172.29.240.1#53
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Non-authoritative answer:
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Name:   b.root-servers.net
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Address: 199.9.14.201
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> server 199.9.14.201
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Default server: 199.9.14.201
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Address: 199.9.14.201#53
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> set type=ns
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> com.
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Server:         199.9.14.201
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Address:        199.9.14.201#53
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Non-authoritative answer:
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*** Can't find com.: No answer
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Authoritative answers can be found from:
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com     nameserver = a.gtld-servers.net.
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com     nameserver = b.gtld-servers.net.
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com     nameserver = c.gtld-servers.net.
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com     nameserver = d.gtld-servers.net.
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com     nameserver = e.gtld-servers.net.
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com     nameserver = f.gtld-servers.net.
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com     nameserver = g.gtld-servers.net.
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com     nameserver = h.gtld-servers.net.
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com     nameserver = i.gtld-servers.net.
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com     nameserver = j.gtld-servers.net.
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com     nameserver = k.gtld-servers.net.
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com     nameserver = l.gtld-servers.net.
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com     nameserver = m.gtld-servers.net.
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a.gtld-servers.net      internet address = 192.5.6.30
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a.gtld-servers.net      has AAAA address 2001:503:a83e::2:30
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b.gtld-servers.net      internet address = 192.33.14.30
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b.gtld-servers.net      has AAAA address 2001:503:231d::2:30
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c.gtld-servers.net      internet address = 192.26.92.30
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c.gtld-servers.net      has AAAA address 2001:503:83eb::30
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d.gtld-servers.net      internet address = 192.31.80.30
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d.gtld-servers.net      has AAAA address 2001:500:856e::30
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e.gtld-servers.net      internet address = 192.12.94.30
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e.gtld-servers.net      has AAAA address 2001:502:1ca1::30
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f.gtld-servers.net      internet address = 192.35.51.30
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f.gtld-servers.net      has AAAA address 2001:503:d414::30
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> server 192.33.14.30
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Default server: 192.33.14.30
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Address: 192.33.14.30#53
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> set type=ns
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> bilibili.com.
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Server:         192.33.14.30
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Address:        192.33.14.30#53
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Non-authoritative answer:
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*** Can't find bilibili.com.: No answer
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Authoritative answers can be found from:
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bilibili.com    nameserver = ns3.dnsv5.com.
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bilibili.com    nameserver = ns4.dnsv5.com.
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ns3.dnsv5.com   internet address = 129.211.176.212
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ns3.dnsv5.com   internet address = 162.14.18.188
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ns3.dnsv5.com   internet address = 162.14.24.251
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ns3.dnsv5.com   internet address = 162.14.25.251
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ns3.dnsv5.com   internet address = 18.194.2.137
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ns3.dnsv5.com   internet address = 183.192.201.94
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ns3.dnsv5.com   internet address = 223.166.151.16
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ns3.dnsv5.com   has AAAA address 2402:4e00:1430:1102:0:9136:2b2b:ba61
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ns3.dnsv5.com   internet address = 52.77.238.92
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ns3.dnsv5.com   internet address = 61.151.180.51
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ns4.dnsv5.com   internet address = 101.226.220.12
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ns4.dnsv5.com   internet address = 129.211.176.151
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ns4.dnsv5.com   internet address = 162.14.24.248
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ns4.dnsv5.com   internet address = 162.14.25.248
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ns4.dnsv5.com   internet address = 183.192.164.119
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ns4.dnsv5.com   internet address = 223.166.151.126
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ns4.dnsv5.com   has AAAA address 2402:4e00:1020:1264:0:9136:29b6:fc32
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ns4.dnsv5.com   internet address = 52.198.159.146
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ns4.dnsv5.com   internet address = 59.36.120.147
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> server 129.211.176.212
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Default server: 129.211.176.212
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Address: 129.211.176.212#53
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> set type=a
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> www.bilibili.com.
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Server:         129.211.176.212
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Address:        129.211.176.212#53
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www.bilibili.com        canonical name = a.w.bilicdn1.com.
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>
113
>
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>
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>
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> a.w.bilicdn1.com.
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Server:         129.211.176.212
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Address:        129.211.176.212#53
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a.w.bilicdn1.com        canonical name = g.w.bilicdn1.com.
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Name:   g.w.bilicdn1.com
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Address: 110.43.34.72
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Name:   g.w.bilicdn1.com
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Address: 110.43.33.147
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Name:   g.w.bilicdn1.com
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Address: 110.43.33.166
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Name:   g.w.bilicdn1.com
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Address: 139.159.246.60
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Name:   g.w.bilicdn1.com
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Address: 139.9.62.5
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