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

[lingcherd at gmail.com]

Hi DNS experts,

This may not be bind related but I am seeing some strange things with
this site:
web.da-us.citibank.com.
When going to http://www.citibankonline.com in the US, this is the URL
it forwards to.

The strange thing is, everytime I try to go to the site from work,
after a couple of minutes, the DNS servers at my work place stop
resolving the host web.da-us.citibank.com. And if immediately I logon
to my private isp machine offsite, and do a dig or nslookup, it won't
resolve either.  I would get a SERVFAIL error from nslookup thereafter.
 If I let it sits for 10 minutes or so, nslookup will start working
fine. I never have any problem getting to the site from home.

I find from running dig/nslookup that this host has a tll of 0 . Is
that a false result or if not, could be it causing problem like this?

I've talked to the network people briefly and they are not blocking
access to the site. But since it's really not a work related site, I
haven't really push them to debug their DNS server setup. But if I get
more understanding of pausible cause, then I can talk to them.

THanks!