RE: Iptables can't close port 25 and 110
-----Original Message-----
From: "Ronald Laarman" <ronald@laarman.xs4all.nl>
To: <debian-firewall@lists.debian.org>
Cc: <R.DElia@starcomitalia.com>
Date: Mon, 26 Jan 2004 16:12:04 +0100
Subject: RE: Iptables can't close port 25 and 110
> I already tried reject, I'll give an example to clarify my problem.
>
> Removed all iptable rules an when running a nmap scan (remotely) I get
> the following output:
>
> PORT STATE SERVICE
> 25/tcp open smtp
> 80/tcp open http
> 110/tcp open pop3
> 199/tcp open smux
> 3306/tcp open mysql
>
> I then inserted the following rules:
>
> - IPTABLES -A INPUT -t tcp --destination-port 25 -j REJECT
> - IPTABLES -A INPUT -t tcp --destination-port 80 -j REJECT
> - IPTABLES -A INPUT -t tcp --destination-port 199 -j REJECT
>
> Did a new scan and nmap returned:
>
> PORT STATE SERVICE
> 25/tcp open smtp
> 110/tcp open pop3
> 3306/tcp open mysql
>
> So even if I reject port 25, nmap detects it as open. And if I reject
> port 80, nmap detects it as being closed.
>
> Hope this give a better image of my problem.
Ah. OK, it's strange!:)
Hav u tried telnetting to the 25 port? Does exim responds?
I'm curious...
Radel
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