North American Network Operators Group|
Date Prev | Date Next |
Date Index |
Thread Index |
Author Index |
Re: Security gain from NAT
- From: Dorn Hetzel
- Date: Mon Jun 04 17:56:55 2007
- Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=cEChxR0/W1exmjLaBXEqT3P2CSfdNk7+jWe19eyL0joj4+iMuJNBh2AUryxyvX47O4K8vUij7gehcqOh4hs8CQ9yNqQgIf9pGXvtqydF7yIfixNECHrTHDafM/XTMLSnComSV0IYLFEStbU/imp+OgQzNENf3QF//t+TqEJ6eH4=
- Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=lOv7ist3QRThPefFfn3D473Su3TzYRG7PHm+RFlabhE4O8/4/8s7BeHkklnhQ96MoAHFiEEHHgMHaqzfPGHAaU1jYiVMkAfCOC/q4qDw3kQQfgUCy5JJkF5RT2DPilJDLDMjhE76I1BJiyvAx5fKrSSNXwDmIdksczH7b7O5Xtg=
Well, give the junky little NAT boxes their due. Grubby little home networks running windoze on one or a few computers cause a lot less trouble in the world when there is a junky little NAT box between the house LAN and the big world outside. Better ways to do it? Absolutely! Easier, cheaper and more widely methods that at least squelch a good bit of the crap? Maybe not...
On 6/4/07, Donald Stahl <[email protected]> wrote:
> Also, it is good to control the Internet addressable devices on your network
> by putting them behind a NAT device. That way you have less devices to
> concern yourself about that are directly addressable when they most likely
> need not be. You can argue that you can do the same with a firewall and a
> default deny policy but it's a hell of a lot easier to sneak packets past a
> firewall when you have a directly addressable target behind it than when
> it's all anonymous because it's NATed and the real boxes are on RFC1918.
This is patently untrue. Using a firewall such as CheckPoint, which
integrates NAT into the object definition, makes it just as likely to
accidentally allow traffic to a NAT'd address as it does a real address.
Either you are allowing access to the _object_ or you are not.
If you start messing with the NAT table directly then you open up another
can of worms- namely additional complexity and a greater opportunity for
> So really, those who do not think there is a security gain from NATing don't
> see the big picture.
We see the big picture- we see applications with a ton of extra code to
handle NAT- code that may contain mistakes and end up being compromised.
We see firewalls that need more code to handle NAT'd applications- code
that contains mistakes and can be compromised.
We see firewall rule sets that are more complicated and make less than if
NAT were not involved.
We see security/performance problems that are harder to troubleshoot
because we have to dig through a NAT table to figure out which connection
Keep it simple. NAT is a terrible terrible hack- and it's sad that it's
become so accepted in the maintsream.