a simple DNS problem????

Something is strange.

For the last year I have had a server set up on an ISP that assigns
addresses dynamically. In order to keep it pseudo-static, I have an
account on one of the dynamic DNS providers. Just for kicks, the ISP
blocks port 80 (but not 443) so I have it set up to redirect from http
to https via the dynamic DNS provider, set up my firewall to redirect
from 443 to a non-privileged port, etc.

All was calm and peaceful. I could access the web server on this
machine either via the redirected http URL or via https://TheRealURL.
Today, it has stopped working - i.e., I can browse the server/access
its services if I use the http://RedirectedURL but not if I use
https://TheRealURL. More important, mail to my domain is no longer
being delivered. The IP address hasn't been remapped - I can still
ssh into the box that way.

I checked my registrar and dynamic DNS provider and see nothing
changed. While my ISP recently blocked port 25 outbound, they never
announced anything about inbound. The mail server itself (postfix)
works fine for POP'd mail sucked down from external accounts.

Can anyone suggest a methodology to follow to troubleshoot this? I'm
not a newbie but not ready for an RHCE either. If it matters, I am
running Mandrake 9.2 on the server.

TIA -

Kind regards,
jh

> Something is strange.
>
> For the last year I have had a server set up on an ISP that assigns
> addresses dynamically. In order to keep it pseudo-static, I have an
> account on one of the dynamic DNS providers. Just for kicks, the ISP
> blocks port 80 (but not 443) so I have it set up to redirect from http
> to https via the dynamic DNS provider, set up my firewall to redirect
> from 443 to a non-privileged port, etc.
>
> All was calm and peaceful. I could access the web server on this
> machine either via the redirected http URL or via https://TheRealURL.
> Today, it has stopped working - i.e., I can browse the server/access
> its services if I use the http://RedirectedURL but not if I use
> https://TheRealURL. More important, mail to my domain is no longer
> being delivered. The IP address hasn't been remapped - I can still
> ssh into the box that way.

Hm. So the redirection from RedirectedURL:80 to TheRealURL:443 works,
but a direct connection to TheRealURL:443 fails? That is strange.

Made any changes to your firewall lately?

I suggest getting a port scan of your host, to see what ports are still
open to the public. Try the one at http://www.dslreports.com/scan, or
"Shields Up" at grc.com, or you might find some other free ones.

Good luck,
Andrew.

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