Slashdot: UK ISP PlusNet Testing Carrier-Grade NAT Instead of IPv6

William Herrin bill at
Wed Jan 16 18:17:55 UTC 2013

On Wed, Jan 16, 2013 at 12:09 PM, fredrik danerklint
<fredan-nanog at> wrote:
>> Barring a few fanatics, everyone here
>> has known for several years now that CGN would be required for
>> continuing IPv4 support regardless of the progress of IPv6.
>> If you spin it right, it's a "Free network-based firewall to be
>> installed next month. Opt out here if you don't want it." And the
>> fewer than 1 in 10 folks who opt out really aren't a problem.
> Even tough you have very good arguments, my suggestion would be to have a
> class A network (I got that right, right?) for all the users and only having
> 6rd as service on that network.

ARIN and IETF cooperated last year to allocate for CGN
use. See RFC 6598. This makes it possible to implement a CGN while
conflicting with neither the user's RFC1918 activity nor the general
Internet's use of assigned addresses. Hijacking a /8 somewhere instead
is probably not a great move.

Bill Herrin

William D. Herrin ................ herrin at  bill at
3005 Crane Dr. ...................... Web: <>
Falls Church, VA 22042-3004

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