Check that www.cernet.edu.cn exists for IPv4 in case we have a typo on the domain name. Use dig to query the local name server (::1).


; <<>> DiG 9.4.1-P1 <<>> +trace +all cernet.edu.cn soa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 783
;; flags: qr ra; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 14

;; QUESTION SECTION:
;.				IN	NS

;; AUTHORITY SECTION:
.			3600000	IN	NS	L.ROOT-SERVERS.NET.
.			3600000	IN	NS	I.ROOT-SERVERS.NET.
.			3600000	IN	NS	B.ROOT-SERVERS.NET.
.			3600000	IN	NS	M.ROOT-SERVERS.NET.
.			3600000	IN	NS	A.ROOT-SERVERS.NET.
.			3600000	IN	NS	J.ROOT-SERVERS.NET.
.			3600000	IN	NS	K.ROOT-SERVERS.NET.
.			3600000	IN	NS	E.ROOT-SERVERS.NET.
.			3600000	IN	NS	H.ROOT-SERVERS.NET.
.			3600000	IN	NS	G.ROOT-SERVERS.NET.
.			3600000	IN	NS	C.ROOT-SERVERS.NET.
.			3600000	IN	NS	F.ROOT-SERVERS.NET.
.			3600000	IN	NS	D.ROOT-SERVERS.NET.

;; ADDITIONAL SECTION:
A.ROOT-SERVERS.NET.	457552	IN	A	198.41.0.4
A.ROOT-SERVERS.NET.	457552	IN	AAAA	2001:503:ba3e::2:30
B.ROOT-SERVERS.NET.	415816	IN	A	192.228.79.201
C.ROOT-SERVERS.NET.	158210	IN	A	192.33.4.12
D.ROOT-SERVERS.NET.	154764	IN	A	128.8.10.90
D.ROOT-SERVERS.NET.	154764	IN	AAAA	2001:500:2d::d
E.ROOT-SERVERS.NET.	413136	IN	A	192.203.230.10
F.ROOT-SERVERS.NET.	458423	IN	A	192.5.5.241
F.ROOT-SERVERS.NET.	154159	IN	AAAA	2001:500:2f::f
G.ROOT-SERVERS.NET.	459087	IN	A	192.112.36.4
H.ROOT-SERVERS.NET.	416125	IN	A	128.63.2.53
H.ROOT-SERVERS.NET.	416125	IN	AAAA	2001:500:1::803f:235
I.ROOT-SERVERS.NET.	457659	IN	A	192.36.148.17
I.ROOT-SERVERS.NET.	457659	IN	AAAA	2001:7fe::53

;; Query time: 7 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri May 18 06:54:12 2012
;; MSG SIZE  rcvd: 512

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1837
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 6, ADDITIONAL: 8

;; QUESTION SECTION:
;cernet.edu.cn.			IN	SOA

;; AUTHORITY SECTION:
cn.			172800	IN	NS	a.dns.cn.
cn.			172800	IN	NS	b.dns.cn.
cn.			172800	IN	NS	c.dns.cn.
cn.			172800	IN	NS	d.dns.cn.
cn.			172800	IN	NS	e.dns.cn.
cn.			172800	IN	NS	ns.cernet.net.

;; ADDITIONAL SECTION:
a.dns.cn.		172800	IN	A	203.119.25.1
b.dns.cn.		172800	IN	A	203.119.26.1
c.dns.cn.		172800	IN	A	203.119.27.1
d.dns.cn.		172800	IN	A	203.119.28.1
e.dns.cn.		172800	IN	A	203.119.29.1
ns.cernet.net.		172800	IN	A	202.112.0.44
a.dns.cn.		172800	IN	AAAA	2001:dc7::1
d.dns.cn.		172800	IN	AAAA	2001:dc7:1000::1

;; Query time: 24 msec
;; SERVER: 2001:500:3::42#53(L.ROOT-SERVERS.NET)
;; WHEN: Fri May 18 06:54:12 2012
;; MSG SIZE  rcvd: 294

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 483
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 5, ADDITIONAL: 2

;; QUESTION SECTION:
;cernet.edu.cn.			IN	SOA

;; AUTHORITY SECTION:
edu.cn.			172800	IN	NS	ns2.cuhk.hk.
edu.cn.			172800	IN	NS	ns2.cernet.net.
edu.cn.			172800	IN	NS	dns2.edu.cn.
edu.cn.			172800	IN	NS	deneb.dfn.de.
edu.cn.			172800	IN	NS	dns.edu.cn.

;; ADDITIONAL SECTION:
dns.edu.cn.		172800	IN	A	202.112.0.35
dns2.edu.cn.		172800	IN	A	202.112.0.13

;; Query time: 259 msec
;; SERVER: 2001:dc7:1000::1#53(d.dns.cn)
;; WHEN: Fri May 18 06:54:12 2012
;; MSG SIZE  rcvd: 179

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1326
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 2

;; QUESTION SECTION:
;cernet.edu.cn.			IN	SOA

;; ANSWER SECTION:
cernet.edu.cn.		86400	IN	SOA	ns2.net.edu.cn. szhu.dns.edu.cn. 2009083106 14400 1800 604800 86400

;; AUTHORITY SECTION:
cernet.edu.cn.		86400	IN	NS	ns2.cuhk.edu.hk.
cernet.edu.cn.		86400	IN	NS	dns.edu.cn.
cernet.edu.cn.		86400	IN	NS	dns2.edu.cn.

;; ADDITIONAL SECTION:
dns.edu.cn.		172800	IN	A	202.112.0.35
dns2.edu.cn.		172800	IN	A	202.112.0.13

;; Query time: 150 msec
;; SERVER: 202.112.0.35#53(dns.edu.cn)
;; WHEN: Fri May 18 06:54:12 2012
;; MSG SIZE  rcvd: 178

HTTP

Looking for CNAME of www.cernet.edu.cn
Checking if there is a AAAA for www.cernet.edu.cn ... FAILED.


; <<>> DiG 9.4.1-P1 <<>> www.cernet.edu.cn aaaa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1042
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;www.cernet.edu.cn.		IN	AAAA

;; AUTHORITY SECTION:
cernet.edu.cn.		10800	IN	SOA	ns2.net.edu.cn. szhu.dns.edu.cn. 2009083106 14400 1800 604800 86400

;; Query time: 4 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri May 18 06:54:13 2012
;; MSG SIZE  rcvd: 88

Checking other options ... failed too.

SMTP

MX 0 sea.net.edu.cn
Looking for AAAA on sea.net.edu.cn

DNS

Looking for AAAA of NS ns2.cuhk.edu.hk
Querying 2405:3000:3:60:0:0:0:21 for SOA of cernet.edu.cn over IPv6 ... successful!
Looking for AAAA of NS dns2.edu.cn
No AAAA record for dns2.edu.cn
Looking for AAAA of NS dns.edu.cn
No AAAA record for dns.edu.cn

NTP

Looking for an A record for ntp.cernet.edu.cn
Looking for an A record for clock.cernet.edu.cn
Looking for an A record for time.cernet.edu.cn
Looking for an A record for chime.cernet.edu.cn

XMPP

Looking for a SRV record for _xmpp-client._tcp.cernet.edu.cn
Looking for a SRV record for _xmpp-server._tcp.cernet.edu.cn

Last Updated: Thu May 17 21:24:15 2012 UTC