在终端下执行
dig +trace www.baidu.com
会大概每 5 次返回一次 ns-6ors.ipv6forummalaysia.com 这种莫名奇妙的根 DNS 服务器地址,如下
$ dig +trace www.baidu.com
; <<>> DiG 9.8.3-P1 <<>> +trace www.baidu.com
;; global options: +cmd
. 30987 IN NS ns-6ors.philv6forum.org.
. 30987 IN NS ns-6ors.ipv6forummalaysia.com.
. 30987 IN NS ns0-6ors.dns-lab.net.
. 30987 IN NS ns1-6ors.dns-lab.net.
. 30987 IN NS ns2-6ors.dns-lab.net.
. 30987 IN NS ns3-6ors.dns-lab.net.
. 30987 IN NS ns4-6ors.dns-lab.net.
. 30987 IN NS ns5-6ors.dns-lab.net.
. 30987 IN NS ns-6ors.ix.ru.
. 30987 IN NS ns-6ors.dns-lab.net.
. 30987 IN NS ns-6ors.cattelecom.com.
dig: couldn't get address for 'ns-6ors.philv6forum.org': no more
正确的结果应该是
$ dig +trace www.baidu.com
; <<>> DiG 9.8.3-P1 <<>> +trace www.baidu.com
;; global options: +cmd
. 2819 IN NS e.root-servers.net.
. 2819 IN NS g.root-servers.net.
. 2819 IN NS b.root-servers.net.
. 2819 IN NS j.root-servers.net.
. 2819 IN NS h.root-servers.net.
. 2819 IN NS i.root-servers.net.
. 2819 IN NS c.root-servers.net.
. 2819 IN NS a.root-servers.net.
. 2819 IN NS m.root-servers.net.
. 2819 IN NS l.root-servers.net.
. 2819 IN NS d.root-servers.net.
. 2819 IN NS f.root-servers.net.
. 2819 IN NS k.root-servers.net.
;; Received 228 bytes from 218.2.2.2#53(218.2.2.2) in 118 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.
;; Received 491 bytes from 198.97.190.53#53(198.97.190.53) in 361 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.
;; Received 201 bytes from 192.5.6.30#53(192.5.6.30) in 288 ms
www.baidu.com. 1200 IN CNAME www.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 ns5.a.shifen.com.
a.shifen.com. 1200 IN NS ns3.a.shifen.com.
a.shifen.com. 1200 IN NS ns2.a.shifen.com.
;; Received 228 bytes from 112.80.248.64#53(112.80.248.64) in 15 ms
有谁知道这是怎么回事吗?