为什么亚马逊自己都不用 route 53

C:\Users\louis>nslookup -qt=ns amazon.com
服务器: google-public-dns-a.google.com
Address: 8.8.8.8

非权威应答:
amazon.com nameserver = pdns1.ultradns.net
amazon.com nameserver = ns4.p31.dynect.net
amazon.com nameserver = ns3.p31.dynect.net
amazon.com nameserver = ns2.p31.dynect.net
amazon.com nameserver = ns1.p31.dynect.net
amazon.com nameserver = pdns6.ultradns.co.uk

C:\Users\louis>nslookup -qt=ns amazon.cn
服务器: google-public-dns-a.google.com
Address: 8.8.8.8

非权威应答:
amazon.cn nameserver = ns1.dynect.cn
amazon.cn nameserver = ns2.dynect.net.cn
amazon.cn nameserver = ns1.dynect.net.cn
amazon.cn nameserver = ns2.dynect.cn
amazon.cn nameserver = ns4.p31.dynect.net
amazon.cn nameserver = ns3.p31.dynect.net
amazon.cn nameserver = u5.amazon.cn
amazon.cn nameserver = ns2.p31.dynect.net
amazon.cn nameserver = ns1.p31.dynect.net
amazon.cn nameserver = u2.amazon.com

C:\Users\louis>nslookup -qt=ns z.cn
服务器: google-public-dns-a.google.com
Address: 8.8.8.8

非权威应答:
z.cn nameserver = pdns4.ultradns.org
z.cn nameserver = ns2.p31.dynect.net
z.cn nameserver = pdns1.ultradns.net
z.cn nameserver = ns4.p31.dynect.net
z.cn nameserver = ns3.p31.dynect.net
z.cn nameserver = ns1.p31.dynect.net
z.cn nameserver = ns2.dynect.cn
z.cn nameserver = ns1.dynect.cn
z.cn nameserver = ns1.dynect.net.cn
z.cn nameserver = ns2.dynect.net.cn