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IP Address Shortage
webslacker wrote in
to send us a news.com story that talks about the upcoming
IP Address Shortage.
Talks about IPv6 and other related topics. Nothing
phenomonal, but its interesting... how many class C's do we
have left anyway?
I remember this scare came up two or three years ago. Bob Metcalfe (of Ethernet and 3Com fame) was the one really pushing the issue then. Disaster didn't happen then, and the situation isn't critical now. There are still lots of class C's available for the near future, and if they disappear quicker than expected, there are some almost empty class A's and B's that could be subdivided. Nobody really needs a class A anyway.
This won't last us indefinately, if we get 250 real IP addresses per household we would run out. On the other hand, the only sane way to give every gadget, appliance, outlet and lightswitch in a house its own IP address is to use the 10.0.0.0/8 network, so it's not an issue for the rest of the world. IPv6 is still the best long term solution (just like it was 2-3 years ago). What's the hold up? It works, all decent OS's support it natively, when are the backbone providers going to start swithching, and encouraging their clients to switch?
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Open mind, insert foot.
Where is IPv6 hard to implement?
The transition from IPv4 -> IPv6 should be totally transparent. Things like TCP and UDP should work under IP with no problems at all, since they don't themselves deal with things like IP addresses or quality-of-service.
IPv6 was designed from the drawing board to be an easy upgrade. IPv4-compatible address space was built-in, and the protocol itself is meant to allow hosts to inter-communicate between IPv4 and IPv6 hosts on mixed networks.
A "funky" (even if simple) multi-level proxy system as you say is simply a rather nasty band-aid. While something like this may work, it introduces a tremendous amount of complexity. You'd still need to have things like web servers, e-mail gateways, etc., on globally visible IP's, and there are useful reasons to have individual PC's visible as well. Behind NAT, you lose a lot of usefulness out of Internet hosts. If such usefulness isn't a factor (such as on networks where the machines are already firewalled into next-to-nothingness), this is probably fine, and using private addresses with NAT is acceptable (and even desirable).
This is a plea, from me personally, and also from me as an employee of ARIN.
/8 (e.g. 10.0.0.0/8) /16 (e.g. 192.168.0.0/16) /24 (e.g. 192.149.252.0/24) /32 (e.g. 206.170.14.74/32)
/23:
Please stop using classful naming. Class A, B, and C really don't have much meaning these days. Use CIDR - it's more specific and just all-around better.
$0.10 Tutorial:
Class A is a
Class B is a
Class C is a
Single IP is a
There you go. I'm sure you can figure out how other networks are specified. For instance, the network slashdot is on is a
206.170.14.0/23
Isn't that better than saying "two class C's"?
First, it is impossible for every IP address out there to be used. Routing is the evil here. Every little network has to have some contiguous IP block. For a small office it could be a /28 up to a /24. There will always be some IP addresses extra for future growth and because things come in powers of two. If you are very good, 50% coverage is possible. A group of offices becomes a corporation which needs a contiguous (if possible) block under which all of the offices live. Of course we need to have room for future addition of offices. Here, using 50% of our sub-blocks again would be good. Now we are to a total of 25% of the IP's used.
This process goes all the way up to the backbone providers.
We could get greater than a 50% coverage, but at the cost of a management nightmare and larger routing tables. You want to keep an office in the same IP block so that it is one router entry. The same with a corporation. Otherwise, by the time you get a few hops from the end-user toward the backbone you will have router tables too large to handle.
That being said. There are some /8's out there that I think could be broken up. Some of the major players in the Internet's early days got /8's (Class A's) because no one ever dreamed that whole world would be trying to get IP addresses.
Second, I think NAT is only a temporary and mostly an unsatisfactory solution. NAT uses one IP address for a bunch of IP devices. A proxy server has the one IP address and all traffic goes through it. I say it is unsatisfactory, because you cannot run servers multiple servers listening on the same port behind a proxy. You can get away with one mail or one web server by telling the proxy anything for port 25 goes to the mail server or for port 80 goes to the web server, but a second web server would have to run on another port. In short, only clients can go behind a NAT proxy. Eventually we will run out of IP addresses for servers also.
Third, yes your toaster will need to have an IP address. Any device in your house will want to communicate to other devices in your house. Your toaster could set off the fire alarm (which has its own IP) when toasting gets out of hand or blink an icon on your desktop when your toast is done. If a device communicates, it needs an address. If IP is the protocol used, it needs an IP address.
Finally, I'm not sure IPv6 is a good solution. It just gives us a new ceiling in the total number of IP addresses. Granted the ceiling is really damned high, but try telling an ARPAnet boy in the 70's that 32-bits is not enough. I would rather see a variable length address. Give my house a prefix (1.2.3.4.5) and let me assign after that. Everyone else just needs to know that something beginning with my house prefix comes to me. ISP would have their own prefix and their customers would be underneath that. This is a rough, but it might work.
Also, IPv6 is missing other features that I would like to see if we are going to upgrade the 'net. Realtime transmission is top on that list.