SV: CPE Residential IPv6 Security Poll

erik.taraldsen at erik.taraldsen at
Tue Sep 20 10:24:01 CEST 2016

With all due respect to the actual power user out there.  For each one of them, there is at least 20 who think they are power users who base their knowledge on rumors and misconceptions.   They are often vocal (forums and coments on news sites) and they are the once who often are enlisted to help Ma & Pa Kettle.  At least that is what we see a lot of in Norway.  They simply do not have the ability to correctly diagnose the issues.  Solutions often involve "you need bigger antennas on the router", "Apple routers are allways the best", "the ISP supplied router allways suck".

So Bob-the-power-user buy the expencive huge antenna router and install at M&PK.  It does not have dual stack, therefore the application at M&PK therefore never tries IPv6 and the older UPnP solution works for them.  Bob gets an re confrimation that big antenas helps, and that the ISP router sucks.  Where a simpler and cheeper solution would be to modify the firewall settings of the ISP router.

Since I reprecent the ISP and spesificaly the ISP supplied router (where we do patch security flaws, add features, optimise DSL and wlan drivers, attack bufferbloat and give the customers the posibility of remote support.  Unlike a lot of retail products which often have to live with the software it was shiped with).  How do we set up the routers IPv6 setting in such a way that Bob-the-power-user do not have to be called in by M&PK to fix their broken app/network, but still maintain a level of security for them?  Is some sort of balanced the way to go?  Should we again push our vendors for PCP/UPnP support?


Fra: at < at> på vegne av Ted Mittelstaedt <tedm at>
Sendt: 19. september 2016 23:23
Til: Bjørn Mork
Kopi: ipv6-ops at
Emne: Re: CPE Residential IPv6 Security Poll

I can tell you that -today- in my location both CenturyLink and Comcast
(giant ISPs) supply IPv6 by default on their residential CPEs - and both
of those CPEs have "inbound block outbound allow" on by default on IPv6.
  As far as I know neither support UPnP on IPv6

I think you are overthinking this.  If a CPE has no IPv6 support but it
has UPnP support over IPv4 then things "work"   If a CPE has IPv6
support but no UPnP support over IPv6, then things are also going to
"work" - on IPv4.  They may break on IPv6 with a "block everything" IPv6
rule in which case the end user is undoubtedly going to complain to the
toaster manufacturer not you, and that toaster maker is either
going to tell their customer "disable ipv6 on your ISP CPE" or they are
going to fix their toaster so that it doesn't try using UPnP over IPv6,
only IPv4.

Your job is to not assume your customers are all morons.  It is to make
it safe for the ones who are, and make it usable for the ones who aren't
and want to run their own show.  Provide the needed buttons in the CPE
to enable or disable IPv6 and to allow your customers to shut off your
CPE's interference and be done with it.

As an ISP you of all people should understand how powerful the Internet
is.  If you make your stuff configurable for power users, and document
it, then the Ma & Pa Kettle customers are going to engage their friend's
son who IS a power user and can search the Internet and follow simple
directions and fix their problem with their web cam or whatever it is
that is demanding UPnP.

If however you default to open, then when Ma & Pa Kettle eventually get
cracked, and call in the power user, that power user is going to
discover your default firewall on IPv6 is open and realize that you
created a huge whole bunch of work for him since he will now have to
put back together a PC for the morons.   He isn't going to appreciate
that and will badmouth you online.

Nobody with brains is going to go online and badmouth an ISP that
supplies a CPE that has defaults that error on the side of
protection-of-morons.   But they are going to badmouth an ISP that
supplies a CPE
that has defaults that allow morons to get easily broken into - because
it's them who are going to be sucked into putting those systems back
together.  And they are really going to badmouth an ISP that supplies a
CPE that can't have it's internal firewall turned off.


On 9/19/2016 1:29 PM, Bjørn Mork wrote:
> Ted Mittelstaedt<tedm at>  writes:
>> This kind of mirrors the "default" security policy on IPv4 CPEs (since
>> those CPE's have NAT automatically turned on which creates a "block in,
>> permit out" kind of approach.) so I'm not sure why you would want to
>> default it to being different for IPv6.
> I was explained one reason today: No CPEs implement UPnP support for
> IPv6 [1].
> This makes the effect of the similar IPv4 and IPv6 policies quite
> different.  UPnP aware applications will set up the necessary NAT rules
> for IPv4, allowing inbound connections etc. But if you want the same
> applications to work over IPv6, then the policy must be more open by
> default. Letting the user disable IPv6 filtering is not going to help
> the masses I'm afraid...
> So the question remains: What do ISPs actually do to
>   - allow IPv6, and
>   - secure the end users' networks, and
>   - not break dual stack applications wanting incoming connections
> all at the same time?  Looks like a classical "pick any two".
> Bjørn
> [1] I'm sure someone will come up with an obscure and expensive example
>   of the contrary - the point is that IPv6 UPnP support is not readily
>   available in the residential CPE market.

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