[TriLUG] Questions on dyndns.org

Mike Mueller mjm-58 at mindspring.com
Thu Oct 3 17:53:14 EDT 2002


On Thursday 03 October 2002 15:39, Jeremy Portzer wrote:
> 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!).

Really?  I was replying to Bill who indicated that port redirection did not 
seem to be available at dyndns.org.  I think port redirection is available.
>
> 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.

OK.  But I knew that from the web page.
>
> 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.*

Well, maybe I should read a refresher on DNS, but my concern is port 80 
blocking by an ISP and possible work-arounds because if such a block exists I 
can't put up a website from home, can I?  You just pointed out that DNS does 
not affect port selection so I'm not sure why I need to review DNS right now. 
I am concerned that the practice of port blocking will increase as we go 
forward, so if I don't see it today that's no guarantee that I won't see it 
later.  Port blocking is probably an effective tool for traffic grooming by 
the ISP.  I really don't care if I have to use a gimmick to get around port 
blocking as long as the gimmick works.  If port redirection at dyndns.org is 
a gimmick then so is NAT and masquerading.

-- 
mueller, mike

The larger purpose of the economic order, including Wall Street, is to 
support the material conditions for human existence, not to undermine and 
destabilize them.

-Editorial, The Nation, August 19, 2002



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