From mboxrd@z Thu Jan  1 00:00:00 1970
From: MAB <mabaeyens@eresmas.com>
Subject: Re: ssh
Date: Wed, 15 Jan 2003 18:44:09 +0000
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To: "Simpson, Doug" <dsimpson@friedmancorp.com>, "'netfilter@lists.netfilter.org'" <netfilter@lists.netfilter.org>

El Mar 14 Ene 2003 21:28, Simpson, Doug escribi=F3:
> whoops - forgot this is a dual homed computer and I am opening the eth0=
 to
> the outside world for ssh.
> I did find this -
> iptables -A INPUT -p tcp --syn --destination-port 22 -j ACCEPT

With this rule you mean you accept every incoming packet from the interne=
t=20
through the por 22, and specially packets with the SYN,RST,ACK bit sets t=
o 1=20
(you accept people should establish a connection to the 22 port)

> iptables -A INPUT -p tcp --syn -j DROP

And, out of that, every incoming TCP packet, DROPs

-Miguel Angel Baeyens

KeyID: 0x6FB7A511 en rediris.es