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Re: who gets a /32 [Re: IPV6 renumbering painless?]

  • From: Iljitsch van Beijnum
  • Date: Sat Nov 20 06:59:33 2004

On 19-nov-04, at 17:58, Stephen Sprunk wrote:

these organizations tend to have multiple sites (as you indicate above) but they generally do not have real connectivity between those sites. This means a single large prefix won't do them much good, and basically they're no different than a bunch of smaller single-site organizations.

Don't have "real connectivity"? I've personally worked with dozens of Fortune 500 companies that have internal FR/ATM networks that dwarf AT&T, UUnet, etc. in the number of sites connected. Thousands of sites is common, and tens of thousands of sites in some cases. Do you not consider these networks "real" because each site may only have a 16k PVC to talk to corporate?
That's right. If you need internet access, you need it to be faster than 16 kbps. As far as I can tell, it's pretty rare for an organization of this size to have their own IP network that they use to connect all their sites to the global internet, for the simple reason that leased lines, framerelay or ATM capacity is generally more expensive than IP connectivity.

So a single large address block is of little use to such an organization, unless they get to announce more specifics all over the place.

learn to love renumbering. And again, IPv6+NAT makes no sense as NAT works much better with IPv4 and with NAT you don't really need the larger address space.

If I have a disconnected network, why would I use NATs or be forced to renumber periodically?
I have no idea. Use unique local addresses instead.

Why should disconnected networks use global addresses (and pay rent to the RIRs) in the first place?
There aren't many networks around that are truly disconnected. Even "disconnected" networks connect to stuff that connects to other stuff that connects to the internet at some point. This means that "disconnected" address space must not overlap with addresses used on the internet. We have that in RFC 1918. However, "disconnected" networks tend to interconnect with other "disconnected" networks from time to time, which means trouble if they both use the same address space. This is where ULAs come to the rescue.