Seperating web & e-mail for the same domain name???

[Joseph S D Yao]

On Wed, Dec 08, 1999 at 04:13:04PM +0000, Andrew Ward wrote:
> 
> OK, so I have a domain name, and it points to a static IP address.
> Right?
> 
> Now I have a DSL line feeding a small server that I want to send/
> receive mail from/to for about 30 users.
> 
> But I don't want to be serving up web pages externally through
> a DSL line. I want my ISP (or another ISP) to host those web pages.
> 
> But I want the e-mail and web pages at all be 
> 
> 	bozo at myplace.org
>  
>         and
> 
> 	www.myplace.org
> 
> How do I tell my ISP this? Is this called virtual web hosting? 
> Virtual domain name? What? How is the e-mail and web traffic 
> separated when Internic points DNS lookups to the same address?
> (Or does it?)
> 
> (The ISP in this case is California's Pacific Bell, with the
> small business "enhanced" DSL package.) They are stupid, so 
> I want to know exactly what i am asking for before I do.
> 
> Where the heck can I find a FAQ on this stuff?... Can't seem 
> to find a good one.
> 
> Thanks very much.
> 
> -Andrew
> award at cisco.com

Considering the great degree of difficulty following the above piece of
prose, and the common spelling misteak in your subject line, and the
fact that your ISP may even now be reading your description of them, I'd
be careful with those epithets.

You say that you have a domain name, and that it points to a static IP
address.  OK.  Let's say that your domain name is, as above,
"myplace.org".  Somewhere, there is a name server that is associating
the name "myplace.org" with that IP address, using an "A" record.  That
same place can associate your e-mail destination with the same or
another location using an "MX" record.  It could also associate the
totally separate name "www.myplace.org" with the IP address of either of
the above locations, or of yet another location, using another "A"
record.

Any one of the above-mentioned locations could be your server at the end
of the DSL line.  You do not mention whether that server bears the
static IP address you mentioned at first.  And, any of the above-
mentioned locations could be at any ISP who is willing to accept your
money for the service.

There is no magic in any of this.  It is plain, simple, garden-variety
DNS.  You will find it described in the book "DNS and BIND", currently
in its third edition, written by Albitz and Liu, published by O'Reilly
and Associates, and available not only everywhere that good books are
found, but quite a few other places, as well.  ;-)

All you have to tell your DNS server [presumably, your primary ISP] is
that you would like e-mail destined to "myplace.org" to actually be sent
to another host, and give the name of that host.  Or, to the same host.
Also, tell the hostmaster that you would like the name "www.myplace.org"
to be associated with an IP address, and give him or her the IP address.
Quite simple.

Unix systems can host many different services at once without breaking a
sweat.  In fact, except for e-mail, there is NO provision in DNS to
specify any specific service at any specific host - and for e-mail, that
is only an option, there is no requirement to do so.  Services are
specified by different "ports" on the same host.  Typically, but not
necessarily, e-mail is on port 25, Web is on port 80, DNS is on port 53,
Telnet is on port 23, FTP is on ports 20 and 21 [don't ask], etc.  But
since these are "commonly known ports", you never have to know them -
just point your client program and go - unless the service or a proxy
for it is running on some different port on a particular machine.

Now, if you can find an ISP that you feel will accept your Web pages,
they will probably do it via "virtual hosting" - having multiple names
or even IP addresses refer to the same machine.  But this is a different
mechanism from specifying different IP addresses for different host
names.

And, yes, lest I was too subtle, I did indeed misspeel "misteak" aboive
deliberately.

And, as I was told as a child, there is "a rat" in "separate."

-- 
Joe Yao				jsdy at cospo.osis.gov - Joseph S. D. Yao
COSPO/OSIS Computer Support					EMT-B
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