Re: What's blocking Port 25?
Thanks for the suggestions. I need to study up on the
lsof syntax. I'll put the new machine on-line tomorrow
& hit it from work to see what the 'host' command
shows.
gp
--- John Summerfield <debian@ComputerDatasafe.com.au>
wrote:
> For starters:
> See what addresses exim is listening to
> lsof -c exi -a -i
>
> If that checks out. from outside, see what really
> happens:
>
> telnet Griff.example.com 25
>
> If that checkes out, from outside
> host -t mx Gruff.example.com
>
>
>
> Griffin Palmer wrote:
>
> >This may be one for the firewalls list, but I'm not
> >entirely sure this is a firewall issue, or, at
> least,
> >*entirely* a firewall issue. I'm pretty sure it's
> not
> >an exim issue.
> >
> >I thought I'd see if there are any troubleshooting
> >suggestions from this obviously very experienced
> user
> >base, before trying more specialized lists.
> >
> >I've just installed testing/unstable on my machine.
>
> >
> >I'm running behind a NAT DSL router, with iptables
> on
> >my machine.
> >
> >I have my own domain, running its own DNS, smtp
> host,
> >http host, etc.
> >
> >I'm using exim 4.41, compiled from source, as my
> MTA.
> >
> >I was earlier running exim 3.36-11 on another box,
> >behind the same router, using identical port
> >forwarding. But in the fresh install on more robust
> >hardware, something has gone amiss.
> >
> >I'm pretty sure it's not exim. All the diagnostics
> >check out for exim. I can send from and reply to
> >local-domain addresses, using either mutt or mail.
> >
> >I can also send messages to the outside world. But
> >replies (or original messages) from the outside
> world
> >fall on deaf ears. Eventually, I get an "I've given
> up
> >trying" message from my ISP's MTA -- except in one
> >instance (more on that below).
> >
> >Here's where it gets confusing. Running nmap
> against
> >my machine from outside the domain shows it is
> >answering that Port 25 is closed. This even though,
> >using FireStarter, I've explicitly opened Port 25.
> >
> >I'm *certain* I've properly forwarded Port 25 to
> the
> >correct IP address for my new machine.
> >
> >Here's another oddity: Even though my machine
> replies
> >'closed' to Port 25 scans, I got one error reply
> with
> >one message attempt from my ISP account that
> suggests
> >the port isn't *entirely* closed.
> >
> >Thinking I might have DNS configuration problems, I
> >tried sending a message to myself@123.457.789.012
> (my
> >user name and IP address substituted for this dummy
> >address). I didn't realize at the time you had to
> >configure exim to accept mail addressed in this
> >fashion.
> >
> >I got an error message back informing me that exim
> had
> >refused to forward the dotted-quad-addressed
> message
> >to my account on my host.
> >
> >So it seems as if *something* is getting through on
> >Port 25.
> >
> >It doesn't seem, though, that it's a matter of
> >messages reaching my host and then exim failing to
> >properly forward them locally: There are no
> >unforwarded messages languishing on exim's input
> >queue.
> >
> >Any troubleshooting ideas would be appreciated.
> >
> > Griff Palmer
> >
> >
> >
> >
> >
> >
> >
> >
>
> --
>
> Cheers
> John
>
> -- spambait
> 1aaaaaaa@computerdatasafe.com.au
> Z1aaaaaaa@computerdatasafe.com.au
> Tourist pics
>
http://portgeographe.environmentaldisasters.cds.merseine.nu/
>
>
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