Check that www.facebook.com 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 facebook.com soa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1901
;; flags: qr ra; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 14

;; QUESTION SECTION:
;.				IN	NS

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

;; ADDITIONAL SECTION:
A.ROOT-SERVERS.NET.	436562	IN	A	198.41.0.4
A.ROOT-SERVERS.NET.	436562	IN	AAAA	2001:503:ba3e::2:30
B.ROOT-SERVERS.NET.	394826	IN	A	192.228.79.201
C.ROOT-SERVERS.NET.	137220	IN	A	192.33.4.12
D.ROOT-SERVERS.NET.	133774	IN	A	128.8.10.90
D.ROOT-SERVERS.NET.	133774	IN	AAAA	2001:500:2d::d
E.ROOT-SERVERS.NET.	392146	IN	A	192.203.230.10
F.ROOT-SERVERS.NET.	437433	IN	A	192.5.5.241
F.ROOT-SERVERS.NET.	133169	IN	AAAA	2001:500:2f::f
G.ROOT-SERVERS.NET.	438097	IN	A	192.112.36.4
H.ROOT-SERVERS.NET.	395135	IN	A	128.63.2.53
H.ROOT-SERVERS.NET.	395135	IN	AAAA	2001:500:1::803f:235
I.ROOT-SERVERS.NET.	436669	IN	A	192.36.148.17
I.ROOT-SERVERS.NET.	436669	IN	AAAA	2001:7fe::53

;; Query time: 7 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri May 18 12:44:02 2012
;; MSG SIZE  rcvd: 512

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 768
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 14

;; QUESTION SECTION:
;facebook.com.			IN	SOA

;; AUTHORITY SECTION:
com.			172800	IN	NS	a.gtld-servers.net.
com.			172800	IN	NS	b.gtld-servers.net.
com.			172800	IN	NS	c.gtld-servers.net.
com.			172800	IN	NS	d.gtld-servers.net.
com.			172800	IN	NS	e.gtld-servers.net.
com.			172800	IN	NS	f.gtld-servers.net.
com.			172800	IN	NS	g.gtld-servers.net.
com.			172800	IN	NS	h.gtld-servers.net.
com.			172800	IN	NS	i.gtld-servers.net.
com.			172800	IN	NS	j.gtld-servers.net.
com.			172800	IN	NS	k.gtld-servers.net.
com.			172800	IN	NS	l.gtld-servers.net.
com.			172800	IN	NS	m.gtld-servers.net.

;; ADDITIONAL SECTION:
a.gtld-servers.net.	172800	IN	A	192.5.6.30
b.gtld-servers.net.	172800	IN	A	192.33.14.30
c.gtld-servers.net.	172800	IN	A	192.26.92.30
d.gtld-servers.net.	172800	IN	A	192.31.80.30
e.gtld-servers.net.	172800	IN	A	192.12.94.30
f.gtld-servers.net.	172800	IN	A	192.35.51.30
g.gtld-servers.net.	172800	IN	A	192.42.93.30
h.gtld-servers.net.	172800	IN	A	192.54.112.30
i.gtld-servers.net.	172800	IN	A	192.43.172.30
j.gtld-servers.net.	172800	IN	A	192.48.79.30
k.gtld-servers.net.	172800	IN	A	192.52.178.30
l.gtld-servers.net.	172800	IN	A	192.41.162.30
m.gtld-servers.net.	172800	IN	A	192.55.83.30
a.gtld-servers.net.	172800	IN	AAAA	2001:503:a83e::2:30

;; Query time: 24 msec
;; SERVER: 192.203.230.10#53(E.ROOT-SERVERS.NET)
;; WHEN: Fri May 18 12:44:02 2012
;; MSG SIZE  rcvd: 493

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 737
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 3, ADDITIONAL: 3

;; QUESTION SECTION:
;facebook.com.			IN	SOA

;; AUTHORITY SECTION:
facebook.com.		172800	IN	NS	ns3.facebook.com.
facebook.com.		172800	IN	NS	ns4.facebook.com.
facebook.com.		172800	IN	NS	ns5.facebook.com.

;; ADDITIONAL SECTION:
ns3.facebook.com.	172800	IN	A	66.220.151.20
ns4.facebook.com.	172800	IN	A	69.171.245.32
ns5.facebook.com.	172800	IN	A	66.220.145.65

;; Query time: 134 msec
;; SERVER: 2001:503:231d::2:30#53(b.gtld-servers.net)
;; WHEN: Fri May 18 12:44:02 2012
;; MSG SIZE  rcvd: 132

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 152
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 3

;; QUESTION SECTION:
;facebook.com.			IN	SOA

;; ANSWER SECTION:
facebook.com.		432000	IN	SOA	ns0.facebook.com. dns.facebook.com. 2012051701 7200 1800 604800 120

;; AUTHORITY SECTION:
facebook.com.		172800	IN	NS	ns4.facebook.com.
facebook.com.		172800	IN	NS	ns5.facebook.com.
facebook.com.		172800	IN	NS	ns3.facebook.com.

;; ADDITIONAL SECTION:
ns3.facebook.com.	3600	IN	A	66.220.151.20
ns4.facebook.com.	3600	IN	A	69.171.245.32
ns5.facebook.com.	3600	IN	A	66.220.145.65

;; Query time: 251 msec
;; SERVER: 69.171.245.32#53(ns4.facebook.com)
;; WHEN: Fri May 18 12:44:03 2012
;; MSG SIZE  rcvd: 176

HTTP

Looking for CNAME of www.facebook.com
Checking if there is a AAAA for www.facebook.com ... FAILED.


; <<>> DiG 9.4.1-P1 <<>> www.facebook.com aaaa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 372
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;www.facebook.com.		IN	AAAA

;; AUTHORITY SECTION:
www.facebook.com.	500	IN	SOA	glb1.facebook.com. dns.facebook.com. 2008112740 10800 3600 604800 86400

;; Query time: 5 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri May 18 12:44:04 2012
;; MSG SIZE  rcvd: 79

Checking other options ... succeeded as www.v6.facebook.com.
Sending...

HEAD / HTTP/1.1
Host: www.v6.facebook.com
User-Agent: ipv6-survey.pl/1.97 http://www.mrp.net/IPv6_Survey.html

Reading ...

HTTP/1.1 200 OK
Cache-Control: private, no-cache, no-store, must-revalidate
Expires: Sat, 01 Jan 2000 00:00:00 GMT
P3P: CP="Facebook does not have a P3P policy. Learn why here: http://fb.me/p3p"
Pragma: no-cache
X-Content-Type-Options: nosniff
X-Frame-Options: DENY
X-XSS-Protection: 1; mode=block
Set-Cookie: datr=fb61T5t5Aclf2f8domxjAYwI; expires=Sun, 18-May-2014 03:14:05 GMT; path=/; domain=.facebook.com; httponly
Set-Cookie: lsd=AVqDXS0K; path=/; domain=.facebook.com
Set-Cookie: reg_ext_ref=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; path=/; domain=.facebook.com
Set-Cookie: reg_fb_gate=http%3A%2F%2Fwww.v6.facebook.com%2F; path=/; domain=.facebook.com
Set-Cookie: reg_fb_ref=http%3A%2F%2Fwww.v6.facebook.com%2F; path=/; domain=.facebook.com
Content-Type: text/html; charset=utf-8
X-FB-Debug: e+XJQO/RNmpJrulR9KLOQBVl54iApe264R+cvaV/sbM=
Connection: close
Content-Length: 34531
Date: Fri, 18 May 2012 03:14:05 GMT

Accessed / [2620:0:1cfe:face:b00c:0:0:3] Response: HTTP/1.1 200 OK

SMTP

MX 10 smtpin.mx.facebook.com
Looking for AAAA on smtpin.mx.facebook.com

DNS

Looking for AAAA of NS ns5.facebook.com
No AAAA record for ns5.facebook.com
Looking for AAAA of NS ns3.facebook.com
No AAAA record for ns3.facebook.com
Looking for AAAA of NS ns4.facebook.com
No AAAA record for ns4.facebook.com

NTP

Looking for an A record for ntp.facebook.com
Found an A or AAAA record. Now looking for a AAAA.
Cannot find a AAAA record for ntp.facebook.com
Cannot find a AAAA record for ntp.ipv6.facebook.com

XMPP

Looking for a SRV record for _xmpp-client._tcp.facebook.com
Looking for a SRV record for _xmpp-server._tcp.facebook.com

Last Updated: Fri May 18 03:14:07 2012 UTC