dig命令，很强大~

dig -q www.google.com +trace

; <<>> DiG 9.7.1-P2 <<>> -q www.google.com +trace
;; global options: +cmd
.			517619	IN	NS	d.root-servers.net.
.			517619	IN	NS	k.root-servers.net.
.			517619	IN	NS	m.root-servers.net.
.			517619	IN	NS	a.root-servers.net.
.			517619	IN	NS	f.root-servers.net.
.			517619	IN	NS	j.root-servers.net.
.			517619	IN	NS	h.root-servers.net.
.			517619	IN	NS	l.root-servers.net.
.			517619	IN	NS	b.root-servers.net.
.			517619	IN	NS	c.root-servers.net.
.			517619	IN	NS	i.root-servers.net.
.			517619	IN	NS	g.root-servers.net.
.			517619	IN	NS	e.root-servers.net.
;; Received 228 bytes from 202.106.0.20#53(202.106.0.20) in 44 ms

com.			172800	IN	NS	i.gtld-servers.net.
com.			172800	IN	NS	e.gtld-servers.net.
com.			172800	IN	NS	b.gtld-servers.net.
com.			172800	IN	NS	d.gtld-servers.net.
com.			172800	IN	NS	m.gtld-servers.net.
com.			172800	IN	NS	j.gtld-servers.net.
com.			172800	IN	NS	g.gtld-servers.net.
com.			172800	IN	NS	a.gtld-servers.net.
com.			172800	IN	NS	f.gtld-servers.net.
com.			172800	IN	NS	h.gtld-servers.net.
com.			172800	IN	NS	l.gtld-servers.net.
com.			172800	IN	NS	k.gtld-servers.net.
com.			172800	IN	NS	c.gtld-servers.net.
;; Received 492 bytes from 192.5.5.241#53(f.root-servers.net) in 244 ms

google.com.		172800	IN	NS	ns2.google.com.
google.com.		172800	IN	NS	ns1.google.com.
google.com.		172800	IN	NS	ns3.google.com.
google.com.		172800	IN	NS	ns4.google.com.
;; Received 168 bytes from 192.12.94.30#53(e.gtld-servers.net) in 369 ms

www.google.com.		1200	IN	CNAME	www-g-com-chn.l.google.com.
;; Received 62 bytes from 216.239.34.10#53(ns2.google.com) in 456 ms

----------- post by gmail~