Check that www.comcast.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 comcast.com soa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 250
;; flags: qr ra; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 14

;; QUESTION SECTION:
;.				IN	NS

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

;; ADDITIONAL SECTION:
A.ROOT-SERVERS.NET.	459853	IN	A	198.41.0.4
A.ROOT-SERVERS.NET.	459853	IN	AAAA	2001:503:ba3e::2:30
B.ROOT-SERVERS.NET.	418117	IN	A	192.228.79.201
C.ROOT-SERVERS.NET.	160511	IN	A	192.33.4.12
D.ROOT-SERVERS.NET.	157065	IN	A	128.8.10.90
D.ROOT-SERVERS.NET.	157065	IN	AAAA	2001:500:2d::d
E.ROOT-SERVERS.NET.	415437	IN	A	192.203.230.10
F.ROOT-SERVERS.NET.	460724	IN	A	192.5.5.241
F.ROOT-SERVERS.NET.	156460	IN	AAAA	2001:500:2f::f
G.ROOT-SERVERS.NET.	461388	IN	A	192.112.36.4
H.ROOT-SERVERS.NET.	418426	IN	A	128.63.2.53
H.ROOT-SERVERS.NET.	418426	IN	AAAA	2001:500:1::803f:235
I.ROOT-SERVERS.NET.	459960	IN	A	192.36.148.17
I.ROOT-SERVERS.NET.	459960	IN	AAAA	2001:7fe::53

;; Query time: 7 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri May 18 06:15:51 2012
;; MSG SIZE  rcvd: 512

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 650
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 14

;; QUESTION SECTION:
;comcast.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: 250 msec
;; SERVER: 2001:500:1::803f:235#53(H.ROOT-SERVERS.NET)
;; WHEN: Fri May 18 06:15:52 2012
;; MSG SIZE  rcvd: 492

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 498
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 5, ADDITIONAL: 10

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

;; AUTHORITY SECTION:
comcast.com.		172800	IN	NS	dns101.comcast.net.
comcast.com.		172800	IN	NS	dns102.comcast.net.
comcast.com.		172800	IN	NS	dns103.comcast.net.
comcast.com.		172800	IN	NS	dns104.comcast.net.
comcast.com.		172800	IN	NS	dns105.comcast.net.

;; ADDITIONAL SECTION:
dns101.comcast.net.	172800	IN	AAAA	2001:558:1002:a:68:87:29:164
dns101.comcast.net.	172800	IN	A	68.87.29.164
dns102.comcast.net.	172800	IN	AAAA	2001:558:1004:7:68:87:85:132
dns102.comcast.net.	172800	IN	A	68.87.85.132
dns103.comcast.net.	172800	IN	AAAA	2001:558:1014:c:68:87:76:228
dns103.comcast.net.	172800	IN	A	68.87.76.228
dns104.comcast.net.	172800	IN	AAAA	2001:558:100a:5:68:87:68:244
dns104.comcast.net.	172800	IN	A	68.87.68.244
dns105.comcast.net.	172800	IN	AAAA	2001:558:100e:5:68:87:72:244
dns105.comcast.net.	172800	IN	A	68.87.72.244

;; Query time: 238 msec
;; SERVER: 192.31.80.30#53(d.gtld-servers.net)
;; WHEN: Fri May 18 06:15:52 2012
;; MSG SIZE  rcvd: 365

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1126
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 5, ADDITIONAL: 0

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

;; ANSWER SECTION:
comcast.com.		3600	IN	SOA	dns101.comcast.net. domregtech.comcastonline.com. 2009085319 7200 3600 1209600 3600

;; AUTHORITY SECTION:
comcast.com.		7200	IN	NS	dns105.comcast.net.
comcast.com.		7200	IN	NS	dns104.comcast.net.
comcast.com.		7200	IN	NS	dns101.comcast.net.
comcast.com.		7200	IN	NS	dns102.comcast.net.
comcast.com.		7200	IN	NS	dns103.comcast.net.

;; Query time: 287 msec
;; SERVER: 2001:558:100a:5:68:87:68:244#53(dns104.comcast.net)
;; WHEN: Fri May 18 06:15:53 2012
;; MSG SIZE  rcvd: 206

HTTP

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


; <<>> DiG 9.4.1-P1 <<>> www.comcast.com aaaa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 557
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

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

;; ANSWER SECTION:
www.comcast.com.	7198	IN	CNAME	www.g.comcast.com.

;; AUTHORITY SECTION:
g.comcast.com.		7200	IN	SOA	gslb01.westchester.pa.bo.comcast.net. dnsadmin.cable.comcast.com. 2008093166 10800 3600 604800 86400

;; Query time: 5 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri May 18 06:15:55 2012
;; MSG SIZE  rcvd: 140

Checking other options ... succeeded as ipv6.comcast.com.
Sending...

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

Reading ...

HTTP/1.1 200 OK
Date: Thu, 17 May 2012 20:45:56 GMT
Server: Microsoft-IIS/7.5
Cache-Control: no-cache, no-store
Pragma: no-cache
Content-Length: 51311
Content-Type: text/html; charset=utf-8
Expires: -1
X-AspNet-Version: 2.0.50727
X-Powered-By: ASP.NET
Set-Cookie: website#sc_wede=1; path=/
Set-Cookie: SC=RC.USID=dbb38c81-fe88-4177-8d14-b25c00982bb2; domain=comcast.com; path=/
Set-Cookie: UCID=60cbb385-8b7e-4fc5-a8ae-885e82522983; domain=comcast.com; path=/
Set-Cookie: ASP.NET_SessionId=ybkvi0frmszdik45myxhi245; path=/; HttpOnly
Set-Cookie: SC=RC.USID=dbb38c81-fe88-4177-8d14-b25c00982bb2&CTY=CHERRY+HILL&ST=NEW+JERSEY&Z=08002&EX=True&GEO=True; domain=comcast.com; path=/
Set-Cookie: BIGipServerpool_comcastcom-cms2=3832174404.14340.0000; path=/
Connection: close

Accessed / [2001:558:1002:5:68:87:64:59] Response: HTTP/1.1 200 OK

SMTP

MX 5 mx4.comcast.com
Looking for AAAA on mx4.comcast.com
MX 5 mx3.comcast.com
Looking for AAAA on mx3.comcast.com
MX 5 mx1.comcast.com
Looking for AAAA on mx1.comcast.com

DNS

Looking for AAAA of NS dns104.comcast.net
Querying 2001:558:100a:5:68:87:68:244 for SOA of comcast.com over IPv6 ... successful!
Looking for AAAA of NS dns101.comcast.net
Querying 2001:558:1002:a:68:87:29:164 for SOA of comcast.com over IPv6 ... successful!
Looking for AAAA of NS dns103.comcast.net
Querying 2001:558:1014:c:68:87:76:228 for SOA of comcast.com over IPv6 ... successful!
Looking for AAAA of NS dns102.comcast.net
Querying 2001:558:1004:7:68:87:85:132 for SOA of comcast.com over IPv6 ... successful!
Looking for AAAA of NS dns105.comcast.net
Querying 2001:558:100e:5:68:87:72:244 for SOA of comcast.com over IPv6 ... successful!

NTP

Looking for an A record for ntp.comcast.com
Looking for an A record for clock.comcast.com
Looking for an A record for time.comcast.com
Looking for an A record for chime.comcast.com

XMPP

Looking for a SRV record for _xmpp-client._tcp.comcast.com
Looking for a SRV record for _xmpp-server._tcp.comcast.com
Found XMPP server xmpp.comcast.com (0, 5269)
Trying to connect to 76.96.69.19 on 5269 ... Connection succeeded

Last Updated: Thu May 17 20:46:03 2012 UTC