Question about this site web.da-us.citibank.com with ttl = 0

[Barry Finkel]

>> Is AAAA record mandatory?

>	No.  But consistantly responding to queries other than A queries
>	is.  RFC 1034 / RFC 1035 describe how to respond to queries for
>	types you don't know about or don't have.  RFC 1034 / RFC 1035
>	are the base DNS specifications.  There is no justifiable reason
>	for any DNS server to get this wrong.
>
>	The nameserver for web.da-us.citibank.com is not RFC 1034 / RFC 1035
>	compliant.

>> How does it cause problem like I described?

>	This will cause the server to be marked as lame.
>
>dig aaaa web.da-us.citibank.com @3dns-c.citibankonline.com +norec
       <<I have omitted the rest of the reply.>>


When I query the nameserver 

     3dns-c.citibankonline.com

for a version, the answer is

     VERSION.BIND.           0S CHAOS TXT    "8.3.7-REL"

I cannot tell if that nameserver is authoritative for the zone

     citibank.com

The domain in question is

     citibank.com
not
     citibankonline.com.

But the WHOIS record for 

     citibank.com

lists these nameservers:

     NS1.NSROOT1.COM 192.193.214.1
     NS2.NSROOT2.COM 199.67.172.1 

and those servers respond:

   NS1: version.bind.           0S CHAOS TXT    "nusnj19-edns01.nsroot2.com"
   NS2: version.bind.           0S CHAOS TXT    "9.2.4"

Of course, I have no idea if those CHAOS TXT records reflect reality.
----------------------------------------------------------------------
Barry S. Finkel
Computing and Information Systems Division
Argonne National Laboratory          Phone:    +1 (630) 252-7277
9700 South Cass Avenue               Facsimile:+1 (630) 252-4601
Building 222, Room D209              Internet: BSFinkel at anl.gov
Argonne, IL   60439-4828             IBMMAIL:  I1004994