Re: IPv6 support in firewalls

[Darren Reed <darrenr () reed wattle id au>]

Marcus J. Ranum wrote:
> Dave Piscitello wrote:
> > I suppose I should begin by answering "why the interest in IPv6?"
> > question. Simply put, we are running out of IPv4 addresses (yeah, I
> > know, the Sky is Falling, NAT will save us forever...). Based on current
> >  consumption rates, some folks speculate that the remaining addresses
> > not yet distributed by IANA will be exhausted by 2009.
>
> This prediction was made before, if I recall correctly. In 1994. Except
> that we were going to run out, uh, in 1999.  Yes, the sky is falling, but
> it appears to be falling fairly slowly and gently. :)
>
> Perhaps something better than IPv6 will still come along. You know,
> like what a few of us suggested back in 1992 - namely doubling
> the address size, left-filling with zeroes, and bumping the
> version number? ;)
..

It's not just this, people today want to deploy/build large scale IP
networks where 10/8 isn't enough, not to mention giving those
addresses visibility to the Internet.

The only way that they can plan to do this is by specifying
that IPv6 is used - there is no other alternative.

Anyone want to start a pool/tab on when the sky will reach the ground? :)


> But, to your real point:
> > I'm not convinced we can even meet the
> > modest (that's as polite as I can be) security baseline we achieve with
> > IPv4 security products with available IPv6 security products. What
> > little I've learned in the short time I've spent asking security
> > companies  about IPv6 support isn't encouraging.
>
> It shouldn't be. Let's see - it took HOW long to even sort out the
> most obvious DOS vectors in V4, which was a vastly simpler
> protocol. The recent rumblings about problems in V6 indicate
> that finding flaws in V6 will be a lot like hunting Passenger
> Pigeons was in the 1700's: point your shotgun at the sky and
> pull the trigger and several will fall at your feet.
>   

The security problems are the same, just that some have different
names now.  Loose/strict source routing options from IPv4 are
present in IPv6 under a new guise - this new costume resulted
in a few platforms shipping with processing of then enabled by
default.  In IPv6 the devils are extension headers and in this case,
the routing extension header (but only type 0, so they say...)

As with IPv4, a standard TCP connection between two IPv6
hosts requires no special options, so if you're looking for an
IPv6 firewall, look for one that simply allows you to block all
packets with extension headers.  This will undoubtedly offend
all manner of IPv6 folks, but that's the place we have to start
with for IPv6.

Darren

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