Check that www.pku.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 pku.edu.cn soa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1426
;; flags: qr ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 14

;; QUESTION SECTION:
;.				IN	NS

;; ANSWER SECTION:
.			220493	IN	NS	e.root-servers.net.
.			220493	IN	NS	m.root-servers.net.
.			220493	IN	NS	j.root-servers.net.
.			220493	IN	NS	h.root-servers.net.
.			220493	IN	NS	d.root-servers.net.
.			220493	IN	NS	c.root-servers.net.
.			220493	IN	NS	g.root-servers.net.
.			220493	IN	NS	k.root-servers.net.
.			220493	IN	NS	f.root-servers.net.
.			220493	IN	NS	a.root-servers.net.
.			220493	IN	NS	l.root-servers.net.
.			220493	IN	NS	i.root-servers.net.
.			220493	IN	NS	b.root-servers.net.

;; ADDITIONAL SECTION:
a.root-servers.net.	89816	IN	A	198.41.0.4
a.root-servers.net.	89816	IN	AAAA	2001:503:ba3e::2:30
b.root-servers.net.	48080	IN	A	192.228.79.201
c.root-servers.net.	435864	IN	A	192.33.4.12
d.root-servers.net.	394213	IN	A	128.8.10.90
d.root-servers.net.	394213	IN	AAAA	2001:500:2d::d
e.root-servers.net.	45400	IN	A	192.203.230.10
f.root-servers.net.	90687	IN	A	192.5.5.241
f.root-servers.net.	395563	IN	AAAA	2001:500:2f::f
g.root-servers.net.	91351	IN	A	192.112.36.4
h.root-servers.net.	48389	IN	A	128.63.2.53
h.root-servers.net.	48389	IN	AAAA	2001:500:1::803f:235
i.root-servers.net.	89923	IN	A	192.36.148.17
i.root-servers.net.	89923	IN	AAAA	2001:7fe::53

;; Query time: 7 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue May 22 13:03:08 2012
;; MSG SIZE  rcvd: 512

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 824
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 6, ADDITIONAL: 8

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

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

;; 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: 125 msec
;; SERVER: 2001:dc3::35#53(m.root-servers.net)
;; WHEN: Tue May 22 13:03:08 2012
;; MSG SIZE  rcvd: 291

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 498
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 5, ADDITIONAL: 2

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

;; AUTHORITY SECTION:
edu.cn.			172800	IN	NS	deneb.dfn.de.
edu.cn.			172800	IN	NS	dns.edu.cn.
edu.cn.			172800	IN	NS	ns2.cuhk.hk.
edu.cn.			172800	IN	NS	ns2.cernet.net.
edu.cn.			172800	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: 192 msec
;; SERVER: 2001:dc7::1#53(a.dns.cn)
;; WHEN: Tue May 22 13:03:08 2012
;; MSG SIZE  rcvd: 176

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1810
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 3

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

;; AUTHORITY SECTION:
pku.edu.cn.		172800	IN	NS	NS.pku.edu.cn.
pku.edu.cn.		172800	IN	NS	NS2.CUHK.EDU.HK.
pku.edu.cn.		172800	IN	NS	SUN1000E.pku.edu.cn.
pku.edu.cn.		172800	IN	NS	PKUNS.pku.edu.cn.

;; ADDITIONAL SECTION:
NS.pku.edu.cn.		172800	IN	A	202.112.7.13
PKUNS.pku.edu.cn.	172800	IN	A	162.105.129.27
SUN1000E.pku.edu.cn.	172800	IN	A	162.105.129.26

;; Query time: 271 msec
;; SERVER: 2001:250:c006::8#53(ns2.cernet.net)
;; WHEN: Tue May 22 13:03:08 2012
;; MSG SIZE  rcvd: 165

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1688
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 4, ADDITIONAL: 3

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

;; ANSWER SECTION:
pku.edu.cn.		3600	IN	SOA	ns.pku.edu.cn. hostmaster.pku.edu.cn. 2012051402 3600 900 604800 86400

;; AUTHORITY SECTION:
pku.edu.cn.		3600	IN	NS	ns2.cuhk.hk.
pku.edu.cn.		3600	IN	NS	pkuns.pku.edu.cn.
pku.edu.cn.		3600	IN	NS	sun1000e.pku.edu.cn.
pku.edu.cn.		3600	IN	NS	ns.pku.edu.cn.

;; ADDITIONAL SECTION:
ns.pku.edu.cn.		3600	IN	A	202.112.7.13
pkuns.pku.edu.cn.	3600	IN	A	162.105.129.27
sun1000e.pku.edu.cn.	3600	IN	A	162.105.129.26

;; Query time: 159 msec
;; SERVER: 202.112.7.13#53(NS.pku.edu.cn)
;; WHEN: Tue May 22 13:03:09 2012
;; MSG SIZE  rcvd: 208

HTTP

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


; <<>> DiG 9.4.1-P1 <<>> www.pku.edu.cn aaaa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1021
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

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

;; ANSWER SECTION:
www.pku.edu.cn.		3599	IN	CNAME	www.lb.pku.edu.cn.

;; AUTHORITY SECTION:
lb.pku.edu.cn.		3599	IN	SOA	ns30.pku.edu.cn. hostmaster.pku.edu.cn. 2012050203 3600 900 604800 86400

;; Query time: 5 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue May 22 13:03:10 2012
;; MSG SIZE  rcvd: 105

Checking other options ... succeeded as www.ipv6.pku.edu.cn.
Connection failed: IO::Socket::INET6: connect: No route to host

Ping to www.ipv6.pku.edu.cn [2001:da8:201:1129:217:a4ff:fe8e:fc0e]

no answer from 2001:da8:201:1129:217:a4ff:fe8e:fc0e

Traceroute to www.ipv6.pku.edu.cn [2001:da8:201:1129:217:a4ff:fe8e:fc0e]

 1  2001:44b8:60::1  0.687 ms  0.617 ms  0.451 ms
 2  2001:44b8:8060:1d::6  0.830 ms  0.822 ms  0.637 ms
 3  2001:44b8:8060:34::1  0.747 ms  0.925 ms  0.542 ms
 4  2001:44b8:b060:7::2  21.590 ms  20.237 ms  19.996 ms
 5  2001:44b8:b070:1::12  20.207 ms  20.269 ms  20.156 ms
 6  2001:44b8:f0a0:5::1  121.010 ms  121.270 ms  121.226 ms
 7  2001:218:2000:5000::15  121.021 ms  121.079 ms  120.934 ms
 8  2001:218:0:2000::91  181.541 ms  122.417 ms  223.196 ms
 9  2001:218:0:2000::13e  173.449 ms  175.136 ms  173.541 ms
10  2001:218:0:2000::159  174.988 ms  174.369 ms  174.152 ms
11  2001:218:0:6000::156  174.311 ms  174.532 ms  174.117 ms
12  2001:7fa:0:1::ca28:a1be  142.541 ms  142.128 ms  141.307 ms
13  2001:252:0:101::1  193.488 ms  194.134 ms  194.961 ms
14  2001:252:0:1::1  189.171 ms  189.263 ms  188.016 ms
15  2001:da8:1:1b::2  189.018 ms  191.076 ms  188.265 ms
16  2001:da8:1:50d::2  189.969 ms  190.722 ms  190.660 ms
17  2001:da8:ac:fff1::2  190.900 ms  191.348 ms  190.230 ms
18  2001:da8:201:fffe::7  191.112 ms  191.910 ms  190.456 ms
19  * 2001:da8:201:fffe::7  3187.656 ms !A  3188.901 ms !A

SMTP

MX 0 mx1.pku.edu.cn
Looking for AAAA on mx1.pku.edu.cn
MX 0 mx2.pku.edu.cn
Looking for AAAA on mx2.pku.edu.cn
MX 0 mx4.pku.edu.cn
Looking for AAAA on mx4.pku.edu.cn
MX 0 mx3.pku.edu.cn
Looking for AAAA on mx3.pku.edu.cn
MX 0 mx5.pku.edu.cn
Looking for AAAA on mx5.pku.edu.cn
MX 0 mx6.pku.edu.cn
Looking for AAAA on mx6.pku.edu.cn

DNS

Looking for AAAA of NS sun1000e.pku.edu.cn
No AAAA record for sun1000e.pku.edu.cn
Looking for AAAA of NS ns2.cuhk.hk
No AAAA record for ns2.cuhk.hk
Looking for AAAA of NS ns.pku.edu.cn
No AAAA record for ns.pku.edu.cn
Looking for AAAA of NS pkuns.pku.edu.cn
No AAAA record for pkuns.pku.edu.cn

NTP

Looking for an A record for ntp.pku.edu.cn
Found an A or AAAA record. Now looking for a AAAA.
Cannot find a AAAA record for ntp.pku.edu.cn
Cannot find a AAAA record for ntp.ipv6.pku.edu.cn

XMPP

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

Last Updated: Tue May 22 03:37:17 2012 UTC