Check that www.nust.edu.pk 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 nust.edu.pk soa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 872
;; flags: qr ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 14

;; QUESTION SECTION:
;.				IN	NS

;; ANSWER SECTION:
.			308302	IN	NS	k.root-servers.net.
.			308302	IN	NS	l.root-servers.net.
.			308302	IN	NS	i.root-servers.net.
.			308302	IN	NS	a.root-servers.net.
.			308302	IN	NS	m.root-servers.net.
.			308302	IN	NS	f.root-servers.net.
.			308302	IN	NS	b.root-servers.net.
.			308302	IN	NS	j.root-servers.net.
.			308302	IN	NS	e.root-servers.net.
.			308302	IN	NS	c.root-servers.net.
.			308302	IN	NS	d.root-servers.net.
.			308302	IN	NS	g.root-servers.net.
.			308302	IN	NS	h.root-servers.net.

;; ADDITIONAL SECTION:
a.root-servers.net.	177625	IN	A	198.41.0.4
a.root-servers.net.	177625	IN	AAAA	2001:503:ba3e::2:30
b.root-servers.net.	135889	IN	A	192.228.79.201
c.root-servers.net.	523673	IN	A	192.33.4.12
d.root-servers.net.	482022	IN	A	128.8.10.90
d.root-servers.net.	482022	IN	AAAA	2001:500:2d::d
e.root-servers.net.	133209	IN	A	192.203.230.10
f.root-servers.net.	178496	IN	A	192.5.5.241
f.root-servers.net.	483372	IN	AAAA	2001:500:2f::f
g.root-servers.net.	179160	IN	A	192.112.36.4
h.root-servers.net.	136198	IN	A	128.63.2.53
h.root-servers.net.	136198	IN	AAAA	2001:500:1::803f:235
i.root-servers.net.	177732	IN	A	192.36.148.17
i.root-servers.net.	177732	IN	AAAA	2001:7fe::53

;; Query time: 15 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon May 21 12:39:39 2012
;; MSG SIZE  rcvd: 512

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 603
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 3, ADDITIONAL: 3

;; QUESTION SECTION:
;nust.edu.pk.			IN	SOA

;; AUTHORITY SECTION:
pk.			172800	IN	NS	auth51.ns.uu.net.
pk.			172800	IN	NS	m-2.pknic.net.pk.
pk.			172800	IN	NS	auth101.ns.uu.net.

;; ADDITIONAL SECTION:
m-2.pknic.net.pk.	172800	IN	A	203.128.7.123
auth51.ns.uu.net.	172800	IN	A	198.6.1.162
auth101.ns.uu.net.	172800	IN	A	198.6.1.210

;; Query time: 42 msec
;; SERVER: 2001:500:2f::f#53(f.root-servers.net)
;; WHEN: Mon May 21 12:39:40 2012
;; MSG SIZE  rcvd: 157

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 952
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;nust.edu.pk.			IN	SOA

;; AUTHORITY SECTION:
nust.edu.pk.		38400	IN	NS	ns1.nust.edu.pk.
nust.edu.pk.		38400	IN	NS	ns2.nust.edu.pk.

;; ADDITIONAL SECTION:
ns1.nust.edu.pk.	38400	IN	A	50.97.105.27
ns2.nust.edu.pk.	38400	IN	A	108.179.194.52

;; Query time: 198 msec
;; SERVER: 198.6.1.210#53(auth101.ns.uu.net)
;; WHEN: Mon May 21 12:39:40 2012
;; MSG SIZE  rcvd: 97

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1093
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;nust.edu.pk.			IN	SOA

;; ANSWER SECTION:
nust.edu.pk.		86400	IN	SOA	ns1.nust.edu.pk. webmaster.nust.edu.pk. 1336596122 10800 3600 604800 10800

;; ADDITIONAL SECTION:
ns1.nust.edu.pk.	86400	IN	A	50.97.105.27

;; Query time: 211 msec
;; SERVER: 50.97.105.27#53(ns1.nust.edu.pk)
;; WHEN: Mon May 21 12:39:40 2012
;; MSG SIZE  rcvd: 95

HTTP

Looking for CNAME of www.nust.edu.pk
Checking if there is a AAAA for www.nust.edu.pk ... FAILED.


; <<>> DiG 9.4.1-P1 <<>> www.nust.edu.pk aaaa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1793
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;www.nust.edu.pk.		IN	AAAA

;; ANSWER SECTION:
www.nust.edu.pk.	86399	IN	CNAME	nust.edu.pk.

;; AUTHORITY SECTION:
nust.edu.pk.		10800	IN	SOA	ns1.nust.edu.pk. webmaster.nust.edu.pk. 1336596122 10800 3600 604800 10800

;; Query time: 5 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon May 21 12:39:41 2012
;; MSG SIZE  rcvd: 97

Checking other options ... failed too.

SMTP

MX 0 mail.nust.edu.pk
Looking for AAAA on mail.nust.edu.pk

DNS

Looking for AAAA of NS ns2.nust.edu.pk
No AAAA record for ns2.nust.edu.pk
Looking for AAAA of NS ns1.nust.edu.pk
No AAAA record for ns1.nust.edu.pk

NTP

Looking for an A record for ntp.nust.edu.pk
Looking for an A record for clock.nust.edu.pk
Looking for an A record for time.nust.edu.pk
Looking for an A record for chime.nust.edu.pk

XMPP

Looking for a SRV record for _xmpp-client._tcp.nust.edu.pk
Looking for a SRV record for _xmpp-server._tcp.nust.edu.pk

Last Updated: Mon May 21 03:09:44 2012 UTC