What I dont understand is the need to stay 1:1 routable. Most all of you larger ISP's could have your own private IP Space by simply running a NAT'd infrastructure. Why not do it for all your customers? Todd ----- Original Message ----- From: "Stewart, William C (Bill), RTSLS" <billstewart@att.com> To: <nanog@trapdoor.merit.edu> Sent: Monday, April 28, 2003 11:27 PM Subject: RE: Re: Get as much IP space as you ever dreamed of, was: Re: Looking to buy IPv4 addresses from class C swamp [Let's try this again without fat-fingering the Send button :-)] Seems like an obvious case for using IPv6. RFC2373 site-local addresses assign a /48, with 16 bits of subnet ID and 64 bits of host ID. The average location probably doesn't have 2**16 extranets on one DMZ; picking a random value usually yields one that nobody you're talking to is also talking to, so almost nobody needs to use NAT for this kind of thing, assuming you plan to tunnel them.