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 Cowles, Steve
> Sent: Thursday, July 08, 2004 6:24 PM
> To: 'General Red Hat Linux discussion list'
> Subject: RE: problems receiving e-mail to my server redux
> 
> 
> Ed McCorduck wrote:
> > 
> > Thanks for your very detailed reply, Steve. I'll try to dig through 
> > your mine of information as best as I am able, but 
> unfortunately it's 
> > mostly way over my head at the present state of my newbie knowledge.
> 
> Ed,
> 
> In short...
> 
> 1) Your domain regsitration seems to be correct. i.e. The 
> recursion from the root servers back to your name server is working.
> 
> 2) Whats not working are queries to your name server; which 
> is listed at 24.24.15.155. Is this the public IP address for 
> your firewall? 
> 
> 3) The reply I got back from the above IP address was an ICMP 
> port unreachable. This is usually caused by your firewall not 
> being properly configured for NAT'ing (port forwarding) to an 
> internal RFC1918 address. In your case, 192.168.1.101
> 
> > At least I understand one of your questions, though, and perhaps my 
> > answer can shed more light on the problem:
> > 
> >> BTW: Is 192.168.1.101 possibly a host behind your firewall???
> > 
> > Yes, 192.168.1.101 is the IP address that I maintain for my Linux 
> > computer, which houses my Web and e-mail (sendmail) servers. My 
> > firewall, which is an integral part of my Linksys router 
> for my home 
> > network, I set up through Port Forwarding to send all port 
> 25, 80 and 
> > 110 queries to this computer.
> 
> As I suspected. Please note that DNS queries require udp and 
> tcp port 53 to be port forwarded. You don't mention these 
> ports above. Also, if your mail server is also at 
> 24.24.15.155, then connections to it are not working. i.e.
> 
> telnet 24.24.15.155 25
> Connecting To 24.24.15.155...Could not open connection to the 
> host, on port
> 25:
> Connect failed
> 
> Are you sure your ISP is not blocking inbound smtp 
> connections? A lot of ISP's are blocking smtp connections for 
> residential customers. If so, then fixing your DNS problem is 
> pointless.


Hi Steve,

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


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