On Sep 26, 2011, at 12:47 PM, Iljitsch van Beijnum wrote: > On 26 Sep 2011, at 18:41 , Keith Moore wrote: > >> The problem isn't in the difficulty of finding these changes and fixing them, for currently maintained code. The problem is in the zillions of systems in the field that have assumptions about 240/4 wired into them, most of which either have no automatic upgrade mechanism, aren't set up to use it, or aren't being maintained. > > This is the traditional problem with using 240/4, but it doesn't really apply in this specific case, because those addresses will only be touched by the CGNs in the ISP network, the routers in the ISP network and the home gateways. and the "home" gateways _never_ expose their external addresses to internal hosts or applications? not even via NAT-PMP or UPnP? (are they really "home" gateways in all cases?) seems to me that if you're an ISP and have the luxury of upgrading all of the CPEs, that's a very compelling case for DS-Lite instead of relying on more v4 address space kludges. but of course the devil is in the details. Keith _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf