The same thought occurred to me. A very large enterprise will not utilize this /10 on a whim; they'd talk to their ISP first. A consumer is unlikely to modify the settings of their home router, except if they download malware that does it for them :) and a consumer router vendor has such a low margin that the last thing they want is to utilize this forbidden /10, generating thousands of tech support calls they can't afford to answer. On Dec 3, 2011, at 20:54, "Henning Schulzrinne" <hgs@xxxxxxxxxxxxxxx> wrote: > Almost all residential customers will use a standard home router; as long as that home router does not make the new space available to customers, it will not be used. Almost all residential users get their home NAT box either from the ISP (who obviously won't ship such a box) or from one of a handful of retail consumer equipment vendors, who won't suddenly switch from RFC 1918 addresses, either (because they don't want to get the support calls). > > I don't think your consumer ISP will have much sympathy if you call them up and tell them that you decided to use 128.59.x.x internally, reconfigured the gateway and can no longer get to Columbia University. > > This is an economics issue: If one big corporate customer with a too-creative sysadmin calls up after "finding" this new address space, this can be dealt with. (Indeed, that large corporate customer probably has non-1918 outward-facing addresses to begin with and will keep them, so they are the least likely target of CGNs.) If 10,000 consumer customers call up because their Intertubes aren't working, the ISP has a problem. > > Thus, I'm having a hard time believing in the theory that the new space will be immediately appropriated for consumer ISPs. By whom, exactly, and on what scale and with what motivation? > > Henning > > On Dec 3, 2011, at 8:36 PM, Noel Chiappa wrote: > >>> From: Doug Barton <dougb@xxxxxxxxxxxxx> >> >>> This argument has been raised before, but IMO the value is exactly >>> zero. The fact that you have a finger to wag at someone doesn't make >>> the costs of dealing with the conflict any smaller. >> >> Perhaps. But I don't know the ISPs' business as well as they do. So I'd like >> to hear their views on this point. (They may well have considered this point >> before deciding to ask for CGN space, and decided the space was still enough >> use to be worth it.) >> >> Noel >> _______________________________________________ >> Ietf mailing list >> Ietf@xxxxxxxx >> https://www.ietf.org/mailman/listinfo/ietf >> > _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf