Shorewall devel - May 2002 - RE: [Shorewall-users] SMTP outbound problem (fwd)

I think we should add an FAQ entry for tcp_ecn.
I remember Tom giving a good description in one of his many responses
and there is mention of it in the pptp page, but I could not find the 
response from Tom about different tcp stacks.

Thanks,

-- 
Steve Herber	herber@thing.com	work: 206-261-0307
Systems Engineer, AMCIS, UoW		home: 425-454-2399

---------- Forwarded message ----------
Date: Sat, 11 May 2002 22:13:54 -0500
From: "Cowles, Steve" <Steve@SteveCowles.com>
To: shorewall-users@shorewall.net
Subject: RE: [Shorewall-users] SMTP outbound problem
> -----Original Message-----
> From: Jim Van Eeckhoutte
> Sent: Saturday, May 11, 2002 9:13 PM
> To: shorewall-users@shorewall.net
> Subject: [Shorewall-users] SMTP outbound problem
> 
> 
> I have a problem with connecting to company email server thru port 25. I 
> encounter cannot connect to server. I can t even telnet 25 to email
> server. Checked with company and no ports are blocked. I''m using
Bering.
> Please if anybody can help, direct me to what imp doing wrong or where
> to look. Thank you.
Just a guess here (I have no experience with Bering), but if you are able to
telnet to other e-mail servers, then try the following:

As root: echo "0" >/proc/sys/net/ipv4/tcp_ecn

Now try to connect to your companies mail server.

If your still unable to connect, then you probably have other problems
related your firewall settings or even your ISP possibly blocking outbound
SMTP connections except to their SMTP servers.

Steve Cowles
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Shorewall-users@shorewall.net
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On Mon, 13 May 2002, Steve Herber wrote:
> I think we should add an FAQ entry for tcp_ecn.
> I remember Tom giving a good description in one of his many responses
> and there is mention of it in the pptp page, but I could not find the 
> response from Tom about different tcp stacks.
>
Are you referring to:

http://www.shorewall.net/pipermail/shorewall-users/2002-May/001226.html 
maybe? 

-Tom
-- 
Tom Eastep    \ Shorewall - iptables made easy
AIM: tmeastep  \ http://www.shorewall.net
ICQ: #60745924  \ teastep@shorewall.net

Yes, that is the one.  Thanks for the link.  With this as an explanation 
and the recent post that explains how to turn the kernel feature on and 
off we have a good faq answer.  The hard part is to figure out the 
question.  Maybe:  The firewall works great but I can''t get to some
sites.

Thanks,

-- 
Steve Herber	herber@thing.com	work: 206-261-0307
Systems Engineer, AMCIS, UoW		home: 425-454-2399

On Mon, 13 May 2002, Tom Eastep wrote:
> On Mon, 13 May 2002, Steve Herber wrote:
> 
> > I think we should add an FAQ entry for tcp_ecn.
> > I remember Tom giving a good description in one of his many responses
> > and there is mention of it in the pptp page, but I could not find the 
> > response from Tom about different tcp stacks.
> >
> 
> Are you referring to:
> 
> http://www.shorewall.net/pipermail/shorewall-users/2002-May/001226.html 
> maybe? 
> 
> -Tom
>

On Mon, 13 May 2002, Steve Herber wrote:
> Yes, that is the one.  Thanks for the link.  With this as an explanation 
> and the recent post that explains how to turn the kernel feature on and 
> off we have a good faq answer.  The hard part is to figure out the 
> question.  Maybe:  The firewall works great but I can''t get to
some sites.
>
Maybe:

"...can''t get to some sites from the firewall itself. My windows
systems
behind the firewall can access these sites fine." 

-Tom
-- 
Tom Eastep    \ Shorewall - iptables made easy
AIM: tmeastep  \ http://www.shorewall.net
ICQ: #60745924  \ teastep@shorewall.net