[TriLUG] Questions on dyndns.org

[Jeremy Portzer]

On Thu, 2002-10-03 at 15:17, Mike Mueller wrote:
> 
> well then the link below describes a service that is is new or invalid or 
> I've missed the point:
> http://support.dyndns.org/guides/portredirect.php
> 

Mike,

I'll have to vote for "missed the point" (but probably because I haven't
explained it too well!).

That service is web redirection.  The web request will initially go to
the server of this company (DynDNS) and then will be forwarded via an
HTTP redirect (or frame gimmickry) to your real server.  Notice that the
title of that document is "Redirecting Web Requests To An Alternate
Port" .  In that example, "www2.yourdomain.com" is the destination web
host, whose IP is updated by dynamic DNS.  The regular yourdomain.com
host is *statically* configured to point to DynDNS's servers.  The
redirection is performed by a web application at DynDNS the company,
which is really unrelated to the DNS protocol and system.

You may want to read a refresher on how DNS and TCP connections work in
general.  Remember, DNS is like a telephone book.  Suppose that you look
up a phone number in the book, and make a phone call.  You get a
recording that says to use your fax machine to connect instead.  The
phone book cannot possibly be "redirecting" you to your fax machine. 
The phone book is only listing telephone numbers!  The recording at the
other end of the phone line is doing the redirection.*

--Jeremy  

*assuming the basic analogy that a phone book has two fields -- name of
company/person and phone number.  I realize that phone books could also
have an indication of fax vs. voice lines.  DNS has no analogous fields,
with the notable exception of e-mail.