From: Aleksandar Milivojevic <amilivojevic@pbl.ca>
To: netfilter@lists.netfilter.org
Subject: Re: Restrict LAN users to send mail to Internet but allow to send mail to other LAN user.
Date: Wed, 27 Oct 2004 13:20:53 -0500 [thread overview]
Message-ID: <417FE705.9020505@pbl.ca> (raw)
In-Reply-To: <20041027145828.9818.qmail@web60402.mail.yahoo.com>
ads nat wrote:
> Now I want to allow LAN users to send emails to each
> other on LAN but want to allow some LAN users to send
> email to Internet(Outside world).
> Is there any way using Linux iptables firewall to
> acieve this requirement.
I will assume that LAN users are allowed to connect to mail server only,
and not to outside world. Controlling this on Sendmail level would be
much more simpler and efficient. Assuming you are using Sendmail as
your MTA. Netfilter isn't suited for this, because there's no way for
it to know if SMTP connection between client (LAN user) and server is
delivery of email addressed to another LAN user, or to somebody at the
outside. Also, Sendmail will take care of generating appropriate error
messages back to the users, while Netfilter would simply block the
traffic without any explanation to the user what happened.
--
Aleksandar Milivojevic <amilivojevic@pbl.ca> Pollard Banknote Limited
Systems Administrator 1499 Buffalo Place
Tel: (204) 474-2323 ext 276 Winnipeg, MB R3T 1L7
next prev parent reply other threads:[~2004-10-27 18:20 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-27 14:58 Restrict LAN users to send mail to Internet but allow to send mail to other LAN user ads nat
2004-10-27 16:54 ` Jason Opperisano
2004-10-27 18:20 ` Aleksandar Milivojevic [this message]
2004-10-28 15:35 ` ads nat
2004-10-28 15:48 ` Jason Opperisano
2004-10-28 16:42 ` Aleksandar Milivojevic
-- strict thread matches above, loose matches on Subject: below --
2004-10-27 18:55 Gary Smith
2004-10-27 19:16 ` Aleksandar Milivojevic
2004-10-27 20:47 Gary Smith
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