problems receiving e-mail to my server redux

[Ed McCorduck]

> -----Original Message-----
> From: redhat-list-bounces at redhat.com 
> [mailto:redhat-list-bounces at redhat.com] On Behalf Of Ed Greshko
> Sent: Wednesday, July 14, 2004 10:06 AM
> To: General Red Hat Linux discussion list
> Subject: RE: problems receiving e-mail to my server redux
> 
> 
> On Wed, 2004-07-14 at 19:11, Ed McCorduck wrote:
> 
> > Here's what my ISP told me about any blocking of smtp connections:
> > 
> > > Road Runner does not block any significant ports on your 
> connection. 
> > > The Road Runner service only blocks ports 137-139 
> inclusive for the 
> > > security of your system. These blocked ports will not affect 
> > > connectivity
> 
> There is nothing wrong with the connection to sendmail at your site.
> 
> [egreshko at misty egreshko]$ telnet 24.24.15.155 25
> Trying 24.24.15.155...
> Connected to syr-24-24-15-155.twcny.rr.com (24.24.15.155). 
> Escape character is '^]'. 220 edsgate.mccorduck.ws ESMTP 
> Sendmail 8.12.8/8.12.8; Wed, 14 Jul 2004 09:54:44 -0400 quit

Well, that's comforting to know, at least. Thanks, Ed. 

 
> The problem is still in DNS....
> 
> [egreshko at misty egreshko]$ host -t mx mccorduck.ws
> ;; connection timed out; no servers could be reached
> 
> A quick nmap scan of your host shows....
> 
> Port       State       Service
> 22/tcp     open        ssh
> 25/tcp     open        smtp
> 80/tcp     open        http
> 110/tcp    open        pop-3
> 111/tcp    open        sunrpc
> 135/tcp    filtered    loc-srv
> 136/tcp    filtered    profile
> 137/tcp    filtered    netbios-ns
> 138/tcp    filtered    netbios-dgm
> 139/tcp    filtered    netbios-ssn
> 143/tcp    open        imap2
> 445/tcp    filtered    microsoft-ds
> 593/tcp    filtered    http-rpc-epmap
> 1024/tcp   open        kdm
> 1400/tcp   filtered    cadkey-tablet
> 6000/tcp   open        X11
> Remote operating system guess: Linux Kernel 2.4.0 - 2.5.20 
> Uptime 0.267 days (since Wed Jul 14 15:37:43 2004) TCP 
> Sequence Prediction: Class=random positive increments
>                          Difficulty=5447144 (Good luck!)
> IPID Sequence Generation: All zeros
> 
> Which indicates that port 53 for your DNS server is not opened.

That's interesting because, as I've mentioned in an earlier post, as
suggested to me I went into my Linksys router/firewall configurator and
through port forwarding specifically set port 53 to be directed to my
home network's IP for my Linux box, which is my Web and e-mail server.
Could a firewall on my Linux machine be blocking this? That doesn't seem
likely since I checked and I have my Linux computer's firewall turned
off (relying--foolishly?--on the main router firewall to protect my
whole network), and besides if connections can be made to my Web server
on this machine through my domain name, it seems to my tiny little
newbie head that the DNS must be working somehow. 


Ed McCorduck
Department of English
State University of New York College at Cortland
http://mccorduck.cortland.edu 
ICQ: http://mccorduck.cortland.edu/pager  
AIM: EdMcCorduck