dig www.sina.com.cn +trace
; <<>> DiG 9.8.1-P1 <<>> www.sina.com.cn +trace
;; global options: +cmd
. 367182 IN NS e.root-servers.net.
. 367182 IN NS g.root-servers.net.
. 367182 IN NS b.root-servers.net.
. 367182 IN NS h.root-servers.net.
. 367182 IN NS i.root-servers.net.
. 367182 IN NS l.root-servers.net.
. 367182 IN NS d.root-servers.net.
. 367182 IN NS k.root-servers.net.
. 367182 IN NS f.root-servers.net.
. 367182 IN NS c.root-servers.net.
. 367182 IN NS m.root-servers.net.
. 367182 IN NS j.root-servers.net.
. 367182 IN NS a.root-servers.net.
;; Received 228 bytes from 127.0.0.1#53(127.0.0.1) in 55 ms
cn. 172800 IN NS c.dns.cn.
cn. 172800 IN NS e.dns.cn.
cn. 172800 IN NS b.dns.cn.
cn. 172800 IN NS d.dns.cn.
cn. 172800 IN NS a.dns.cn.
cn. 172800 IN NS ns.cernet.net.
;; Received 296 bytes from 199.7.91.13#53(199.7.91.13) in 246 ms
sina.com.cn. 86400 IN NS ns1.sina.com.cn.
sina.com.cn. 86400 IN NS ns2.sina.com.cn.
sina.com.cn. 86400 IN NS ns3.sina.com.cn.
sina.com.cn. 86400 IN NS ns4.sina.com.cn.
;; Received 169 bytes from 202.112.0.44#53(202.112.0.44) in 56 ms
www.sina.com.cn. 3600 IN CNAME jupiter.sina.com.cn.
jupiter.sina.com.cn. 3600 IN CNAME polaris.sina.com.cn.
polaris.sina.com.cn. 60 IN A 202.108.33.60
sina.com.cn. 86400 IN NS ns3.sina.com.cn.
sina.com.cn. 86400 IN NS ns4.sina.com.cn.
sina.com.cn. 86400 IN NS ns2.sina.com.cn.
sina.com.cn. 86400 IN NS ns1.sina.com.cn.
;; Received 229 bytes from 123.125.29.99#53(123.125.29.99) in 45 ms