Default security functions on an IPv6 CPE
swmike at swm.pp.se
Thu May 12 10:54:32 CEST 2011
On Thu, 12 May 2011, Ted Mittelstaedt wrote:
We had an argument here at the office regarding firewall in CPE, and my
opinion was that since UNPNv6 isn't really supported anywhere, IPv6 with
deny new sessions might even be worse in practice than NAT44 with UPNP. It
seems Windows 7 does support UPNPv6, but I have yet to locate information
regarding support in shipping software for IPv6 enabled CPEs.
So I would like to withdraw my recommendation before about low-ports
closed but high-ports open. I now believe that it's better to have a
permit ESTABLISHED firewall as default cpe behaviour, and let the clients
request policy changes from the gateway if they want other behaviour.
We have a social contract with users to have the CPE act the same way it
did with NAT, because that's all users know. So for initial deployment the
firewall in the CPE should act the same way the state machine in NAT does,
but of course have UPNPv6 support so as programs get this, they will be
able to interact with the FW.
I realise this will limit deployment of true e2e applications, but I
believe this is unfortunately needed.
Mikael Abrahamsson email: swmike at swm.pp.se
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