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.

Seems like an obvious case for using IPv6.

The trouble is that these extranet connections are between Sun3
boxes running SunOS 3.5 or somesuch. The extranet area is infested
with horrendous legacy and I have a hard time believing it is
feasible to convert it to something modern...

RFC2373 site-local addresses assign a /48,

Site-local is on its way out. Thank $DEITY.

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

umm, because there are protocols (like IPSec) which make end-to-end
assumptions that are broken by NAT?

yes, IPSec can be gotten through NAT, in some very specific cases, but i
have a client who is 1) on ameritech DSL (/29 space allocated) and
2) requires a specifc IPSec setup to communicate with one of their vendors,
an IPSec configuration that won't pass through NAT. if Ameritech (the only
viable DSL choice in their area) NATed, they'd be SOL, unable to
communicate with their vendor.

richard

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?

And what if you want to host a webserver or mailserver?

Why stop there, what about with local exchanges in the PSTN, you could put all
towns on their own extension based PBX and save time in having to allocate phone
numbers..

Steve

Stephen -