RE: problems receiving e-mail to my server redux

From: Ed McCorduck (Ed.McCorduck_at_Cortland.edu)
Date: 07/14/04

  • Next message: Margaret Doll: "Re: Problem: php not working with apache on RedHat 9.0 - solved" 
    Date: Wed, 14 Jul 2004 07:11:09 -0400
To: "General Red Hat Linux discussion list" <redhat-list@redhat.com>

    > -----Original Message-----
    > From: redhat-list-bounces@redhat.com
    > [mailto:redhat-list-bounces@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 

    -- 
redhat-list mailing list
unsubscribe mailto:redhat-list-request@redhat.com?subject=unsubscribe
https://www.redhat.com/mailman/listinfo/redhat-list
  • Next message: Margaret Doll: "Re: Problem: php not working with apache on RedHat 9.0 - solved"

    Relevant Pages

    • Re: network programming: how does s.accept() work?
      ... The program you contact at Google is a server. ... so, the server will usually assign a new port, say 56399, specifically ... connections to a server remain on the same port, ... sockets is what identifies them. ...
      (comp.lang.python)
    • Nimda.E/unknown memory resident, internet-aware processes
      ... a client's NT 4.0 server was infected with what appeared to be ... network traffic and saw several suspect connections. ... one other connection to port 2787. ... along with about 500 other compromised systems on just that one IRC server. ...
      (Incidents)
    • Re: iptables newbie question
      ... so it's not a dedicated server. ... > merely want to limit connections on that port ONLY to the e-mail server ... do you want to be able to establish connections out to ... The same sort of thing happens for any request you make - dns, ntp, web, ...
      (comp.os.linux.security)
    • Re: Sun Volume Manager or Solaris Disk Suite
      ... keyboard or mouse connections. ... I have to buy a RJ45 cable that will connect to a DB9 adapter on one ... port). ... How would putty know that I am trying to connect to a server via a com ...
      (comp.sys.sun.admin)
    • Re: Port Forwarding -- Checking to be sure I understand it
      ... They run an ssh ... server and VNC service. ... If you want to run the tunnel over some port other than 22 (the ... restrictive firewalls that deny all incoming connections and block most ...
      (comp.security.ssh)
    Loading