[thelist] understanding TLDs

[Nick Koleszar]

I have been rooting about the web but have not really found an
understandable explanation of this for me. Can anyone help?

I have some sites hosted with a company blahhost.com

When I set up another site on the server, I get a test url in the form
mynewsitecom.dom.blahhost.com where mynewsitecom is referene to my domain,
mynewsite.com and .dom.blahhost.com is the standard for test URLs with this
company. I have 4 sites set up on the same server, on the same IP address.

The problem is that various people that I know can see 1 or 2 of the sites
but nobody can see all 4. Except for support at blahhost.com and support at
my DSL provider, of course. They can see all 4. I can see only 2 of the 4.

Can somebody please assist my understanding of the mechanics of how this is
handled at a TCP/IP level? I thought that my machine would speak to my ISP's
DNS and be told that dom.blahhosting.com points to IPnumber and then my
machine speaks to the machine on that IPnumber asking for
mynewsitecom.dom.blahhosting.com whereupon the machine at IPnumber passes
the request on to a virtual server and, using http headers, the rest of the
job is completed at http level.

nk