RE: NAT external/Public IP

["Grant Donald" <Grant.Donald () datacash co za>]

With PAT private IP addresses are hidden from the outside world. This basically makes the job of hacking into a system 
more difficult, because the original host's IP address and source port is unknown. 
 
Depending on firewall capabilities (or lack of capabilities) ports may need to be opened inbound for certain 
applications to work (e.g.. ident & pptp). A horizontal scan of such a network could produce a wealth of knowledge, if 
that network does not support port address translation.
 
The PCI body cannot dictate to you which firewall to use, neither can they forbid you from opening specific justified 
ports into your network. What they can do is insist that you use network address translation, only an additional 
hurdle, perhaps just enough to deter a random attacker.
 
Regards
-Grant
________________________________

From: listbounce () securityfocus com on behalf of Ansgar -59cobalt- Wiechers
Sent: Mon 2007/10/29 05:58 PM
To: security-basics () securityfocus com
Subject: Re: NAT external/Public IP



On 2007-10-29 Grant Donald wrote:
> There's a real security benefit in using PAT for internet access from
> staff PC's. Any alternative is most definitely less secure.

I keep seeing this claim being made. Yet I fail to see anyone giving
evidence to support it.

Regards
Ansgar Wiechers
--
"All vulnerabilities deserve a public fear period prior to patches
becoming available."
--Jason Coombs on Bugtraq



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