Potential exim/minires VPN problem

Potential exim/minires VPN problem

[Jason Tishler]

Pierre,

On my laptop, exim/minires has transient DNS lookup problems when I'm
VPN-ed into my company's network, but does not exhibit this behavior
when I'm directly connected to it.

When VPN-ed, I get errors like the following:

    2003-09-12 15:07:36 HL47SO-00014S-5P <= jason.tishler@foo.com H=(tishlerjason.bar.foo.com) [127.0.0.1] P=smtp S=882 id=20030912190735.GH2180@foo.com
    2003-09-12 15:08:01 HL47SO-00014S-5P == jason.tishler@foo.com R=send_to_gateway defer (-36): host lookup for smtp.foo.com did not complete (DNS timeout?)

However, if I run the following:

    $ exim -qqff

then the mail is successfully sent:

    2003-09-12 15:08:12 Start queue run: pid=2500 -qqff
    2003-09-12 15:08:13 HL47SO-00014S-5P => jason.tishler@foo.com R=send_to_gateway T=remote_smtp H=smtp.foo.com [XX.XX.XX.XX]
    2003-09-12 15:08:13 HL47SO-00014S-5P Completed
    2003-09-12 15:08:13 End queue run: pid=2500 -qqff

I can also workaround the problem by creating an /etc/resolv.conf file.

Any ideas on how to further debug this problem?

Thanks,
Jason

-- 
PGP/GPG Key: http://www.tishler.net/jason/pubkey.asc or key servers
Fingerprint: 7A73 1405 7F2B E669 C19D  8784 1AFD E4CC ECF4 8EF6

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

Re: Potential exim/minires VPN problem

[Pierre A. Humblet]

Jason Tishler wrote:
> 
> Pierre,
> 
> On my laptop, exim/minires has transient DNS lookup problems when I'm
> VPN-ed into my company's network, but does not exhibit this behavior
> when I'm directly connected to it.
> 
> When VPN-ed, I get errors like the following:
> 
>     2003-09-12 15:07:36 HL47SO-00014S-5P <= jason.tishler@foo.com H=(tishlerjason.bar.foo.com) [127.0.0.1] P=smtp S=882 id=20030912190735.GH2180@foo.com
>     2003-09-12 15:08:01 HL47SO-00014S-5P == jason.tishler@foo.com R=send_to_gateway defer (-36): host lookup for smtp.foo.com did not complete (DNS timeout?)
> 
> However, if I run the following:
> 
>     $ exim -qqff
> 
> then the mail is successfully sent:
> 
>     2003-09-12 15:08:12 Start queue run: pid=2500 -qqff
>     2003-09-12 15:08:13 HL47SO-00014S-5P => jason.tishler@foo.com R=send_to_gateway T=remote_smtp H=smtp.foo.com [XX.XX.XX.XX]
>     2003-09-12 15:08:13 HL47SO-00014S-5P Completed
>     2003-09-12 15:08:13 End queue run: pid=2500 -qqff
> 
> I can also workaround the problem by creating an /etc/resolv.conf file.
> 
> Any ideas on how to further debug this problem?

Yes, run exim with the resolver debug flag set, exim -d+resolver ......

Pierre

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

Re: Potential exim/minires VPN problem

[Jason Tishler]

Pierre,

On Fri, Sep 12, 2003 at 04:45:07PM -0400, Pierre A. Humblet wrote:
> Jason Tishler wrote:
> > Any ideas on how to further debug this problem?
> 
> Yes, run exim with the resolver debug flag set, exim -d+resolver
> ......

Sorry, I should have mentioned that I found the following:

    http://www.cygwin.com/ml/cygwin/2003-08/msg00735.html

Unfortunately, when I added "-d+dns+resolver" to the following:

    /proc/registry/HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/exim/Parameters/AppArgs

I didn't see any see any difference in exim's log file.  Does the
debugging output go to a different exim log file?

Jason

-- 
PGP/GPG Key: http://www.tishler.net/jason/pubkey.asc or key servers
Fingerprint: 7A73 1405 7F2B E669 C19D  8784 1AFD E4CC ECF4 8EF6

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

Re: Potential exim/minires VPN problem

[Pierre A. Humblet]

Jason Tishler wrote:
> 
> Pierre,
> 
> On Fri, Sep 12, 2003 at 04:45:07PM -0400, Pierre A. Humblet wrote:
> > Jason Tishler wrote:
> > > Any ideas on how to further debug this problem?
> >
> > Yes, run exim with the resolver debug flag set, exim -d+resolver
> > ......
> 
> Sorry, I should have mentioned that I found the following:
> 
>     http://www.cygwin.com/ml/cygwin/2003-08/msg00735.html

That message arrived during my vacation. If you look at it,
the dns server used by exim isn't the same as the dns server he was digging!
It's a case of broken server.

> Unfortunately, when I added "-d+dns+resolver" to the following:
> 
>     /proc/registry/HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/exim/Parameters/AppArgs
> 
> I didn't see any see any difference in exim's log file.  Does the
> debugging output go to a different exim log file?

Yes, it goes to std{err,out} of the service. That will be in /var/log/exim.log
(standard) but if you use exim-config to set the service it goes to
/var/log/exim/cygrunsrv_{err,out}.log

The simplest however would be to call exim from the shell.

Pierre

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

Re: Potential exim/minires VPN problem

[Jason Tishler]

This post is just for the archives and to close this thread...

On Fri, Sep 12, 2003 at 05:31:02PM -0400, Pierre A. Humblet wrote:
> Jason Tishler wrote:
> > I didn't see any see any difference in exim's log file.  Does the
> > debugging output go to a different exim log file?
> 
> Yes, it goes to std{err,out} of the service. That will be in
> /var/log/exim.log (standard) but if you use exim-config to set the
> service it goes to /var/log/exim/cygrunsrv_{err,out}.log
> 
> The simplest however would be to call exim from the shell.

I worked with Pierre to investigate this potential problem off-list --
mainly for privacy reasons.  Our conclusion is the problem is caused by
my company's networking setup and not by exim and/or minires.

My company does not allow unrestricted outbound traffic -- everything
goes through some kind of proxy.  In particular, DNS requests go through
SOCKS servers. [1]  We feel the SOCKS servers are causing the DNS
request timeouts.   This causes minires and in turn exim to fail.

Jason

[1] IMO, these servers are overloaded and somewhat unreliable.

-- 
PGP/GPG Key: http://www.tishler.net/jason/pubkey.asc or key servers
Fingerprint: 7A73 1405 7F2B E669 C19D  8784 1AFD E4CC ECF4 8EF6

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/