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Date:      Tue, 01 Oct 2002 08:04:34 -0300
From:      "Daniel C. Sobral" <dcs@tcoip.com.br>
To:        "Crist J. Clark" <cjc@FreeBSD.ORG>
Cc:        ipfw@FreeBSD.ORG
Subject:   Re: Static NAT
Message-ID:  <3D998142.8070005@tcoip.com.br>
References:  <3D9865DB.5040902@tcoip.com.br> <20021001055502.GC79303@blossom.cjclark.org>

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Crist J. Clark wrote:
> On Mon, Sep 30, 2002 at 11:55:23AM -0300, Daniel C. Sobral wrote:
> 
>>I discovered a nasty problem with the way 1-1 NAT is performed with ipfw 
>>atm (ie, divert throw natd). The problem is that, because a socket is 
>>used for this nat, the firewall becomes vulnerable to DoS attacks 
>>directed to such hosts.
>>
>>Since static 1-1 NAT is pretty straightforward, it could be done in the 
>>kernel-side of ipfw itself, thus avoiding this problem.
>>
>>Anyone have thoughts on the subject?
> 
> 
> What DoS? Only one socket is ever used. Or some other DoS?

Yes, only one socket is used, and it uses mbuf clusters.

> If you don't want to do natd(8) and divert(4), you can do ipfw(8)
> 'fwd' on each machine.

No, fwd is not nat. I need nat.

-- 
Daniel C. Sobral                   (8-DCS)
Gerencia de Operacoes
Divisao de Comunicacao de Dados
Coordenacao de Seguranca
TCO
Fones: 55-61-313-7654/Cel: 55-61-9618-0904
E-mail: Daniel.Capo@tco.net.br
         Daniel.Sobral@tcoip.com.br
         dcs@tcoip.com.br

Outros:
	dcs@newsguy.com
	dcs@freebsd.org
	capo@notorious.bsdconspiracy.net

Some marriages are made in heaven -- but so are thunder and lightning.


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