Great Circle Associates Firewalls
(December 1996)
 

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Subject: RE: Sendmail
From: "Allen D. Harpham" <aharpham @ cnweb . com>
Date: Thu, 12 Dec 1996 08:50:31 -0600 (CST)
To: Firewalls @ GreatCircle . COM

Hi all,

I know this probably has been covered, but I just joined the list.

I am setting up some basic firewalls using Linux 2.x and ipfwadm.  Where I
have run up against some problems is with Sendmail.

I have enable smtp to the firewall and out of the firewall, but when
anyone on the network tries the send out email, sendmail timesout after
connecting to the receiving mail server.

After looking at the packets sent, I discovered what all of you probably
already know, that the receiving mail server tries to perform an "auth" on
port 113 of the firewall.

I realize that I can open up port 113 on the firewall, but to me that
really opens up some security holes.

Has anyone else solved this problem?

TIA, Allen

____________________________________________________________________________
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Computer Consultants of       |     Fax:     (402)462-4670
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