nanog mailing list archives

Re: NAT firewall for IPv6?


From: Dovid Bender <dovid () telecurve com>
Date: Tue, 5 Jul 2016 16:31:37 -0400

You may want to look into a new product by Ixia
https://www.ixiacom.com/products/threatarmor (seems their site is under
maint atm).


On Tue, Jul 5, 2016 at 10:31 AM, Naslund, Steve <SNaslund () medline com>
wrote:

On another note, using a firewall to stop viruses is probably not going to
work in general (unless the firewall has some additional malware detection
engine).

Here is the issue in a nutshell.  A firewall primarily controls where
people can connect to and from on a network.  The problem with that is that
a lot of malware is received from sites that your users intended to go to.
People click on links without knowing where they go and people go to less
than reputable web sites (or reputable sites that we recently
compromised).  If you, by default, allow your users to access the Internet
with a browser they are vulnerable to malware.  Even with malware detection
capability you are still vulnerable to signatures and attacks that are not
yet able to be detected.

Even if filtering was enabled on your Palo Alto for ipv6 it would not help
at this point because you have no idea what signatures it is using to
filter with and when the last time those were updated  I doubt your v4
filtering is of much use either at this point.  URL filtering is largely a
big game of whack a mole that you will lose eventually.  Malware filtering
is based on one or both of the following methods.

        1.  You filter URLs known to be bad players (you are vulnerable
until your protection vendor realizes they are bad players).

        2.  You filter based on adaptive detection of code that looks
suspicious.  This is a bit better but still vulnerable because the bad guys
are always innovating to pass through these devices.

My recommendation would be network malware detection (possibly through a
firewall add-on) as well as good virus/malware detection on the client
computers.  Sometimes the malware is easier to detect at the client because
it reveals itself by trying to access unauthorized memory, processes, or
storage.

Steven Naslund
Chicago IL




-----Original Message-----
From: NANOG [mailto:nanog-bounces () nanog org] On Behalf Of Edgar Carver
Sent: Friday, July 01, 2016 9:29 PM
To: nanog () nanog org
Subject: NAT firewall for IPv6?

Hello NANOG community. I was directed here by our network administrator
since she is on vacation. Luckily, I minored in Computer Science so I have
some familiarity.

We have a small satellite campus of around 170 devices that share one
external IPv4 and IPv6 address via NAT for internet traffic. Internal
traffic is over an MPLS.

We're having problems where viruses are getting through Firefox, and we
think it's because our Palo Alto firewall is set to bypass filtering for
IPv6. Unfortunately, the network admin couldn't give me the password since
a local consultant set it up, and it seems they went out of business. I
need to think outside the box.

Is there some kind of NAT-based IPv6 firewall I can setup on the router
that can help block viruses? I figure that's the right place to start since
all the traffic gets funneled there. We have a Cisco Catalyst as a router.
Or, ideally, is there an easy way to turn off IPv6 completely? I really
don't see a need for it, any legitimate service should have an IPv4 address.

I'd really appreciate your advice. I plan to drive out there tomorrow,
where I can get the exact model numbers and stuff.

Regards,
Dr. Edgar Carver



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