Running out of Internet addresses? -- TCP/IP list http://www-mice.cs.ucl.ac.uk/multimedia/misc/tcp_ip/8813.mm.www/0121.html http://www-mice.cs.ucl.ac.uk/multimedia/misc/tcp_ip/8813.mm.www/0144.html http://www-mice.cs.ucl.ac.uk/multimedia/misc/tcp_ip/8813.mm.www/0156.html http://www-mice.cs.ucl.ac.uk/multimedia/misc/tcp_ip/8813.mm.www/0178.html http://www-mice.cs.ucl.ac.uk/multimedia/misc/tcp_ip/8813.mm.www/0180.html http://www-mice.cs.ucl.ac.uk/multimedia/misc/tcp_ip/8813.mm.www/0237.html http://www-mice.cs.ucl.ac.uk/multimedia/misc/tcp_ip/8813.mm.www/0244.html ------------------------------------------------------------------------- Roy Smith (25 November 1988): Has anybody made any serious estimates of how long it will be before we run out of 32-bit IP addresses? (Silly question; I'm sure a very great amount of thought has been given to it by many people.) With the proliferation of such things as diskless workstations, each of which has its own IP address (not to mention terminal multiplexors which eat up one IP address per tty line!), it seems like it won't be too long before we just plain run out of addresses. Yes, I know that 2^32 is a hell of a big number, but it seems like we won't get anywhere near that number of assigned addresses before we effectively run out because most nets are sparsely populated. My little bit of wire, for example, has 256 allocated addresses yet I'm only actually using 30 or so. -- Roy Smith, System Administrator Public Health Research Institute {allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri!roy@uunet.uu.net "The connector is the network" ------------------------------------------------------------------------- CERF (27 Nov 1988): Roy, As you noted, the allocations are often larger than the actual host count because of the way net numbers must be bound to a chunk of address space in the 32 bit formats available. We should be worried about this and should be thinking about how to expand the available address space. Possibilities include adopting ISO IP numbering (variable length - non-trivial), introducing a 64 bit format (a new IP version number would probably be needed), adding an extended address option (awkward, I suspect), others? Vint Cerf ------------------------------------------------------------------------- Frank Kastenholz (28 Nov 88): A quick perusal of my copy of Internet Numbers indicates that there are a fair number of assigned addresses that are not connected to the Internet - perhaps these addresses could be reclaimed - there is one class A, about 40 class B and I have not counted how many class C addresses that are not connected. This is not a long term solution, but if a crunch comes quickly then it may be a temporary solution that would last long enough to get a proper solution done. Frank Kastenholz Eastman Kodak ------------------------------------------------------------------------- CERF (29 Nov 1988): Jon, The way I read it, there are 127 possible class A nets, 16,383 class B nets, roughly 2M+ class C nets, and a bunch (2**28 - 1) of broadcast addresses. The large number of class C nets available should have been sufficient, but we are experiencing some difficulty dealing with large numbers of nets at the IP gateway level (table and routing update sizes). Subnetting works better with class B network format, because there is some room for subnet and host address space. Reparsing the class C address space might be a helpful step towards making more nets effectively available. Vint ------------------------------------------------------------------------- postel (29 Nov 88): Vint: You are correct about the number of network numbers, 126 class A, 16K class B, and 2M class C. This small address space may be come a problem in a few years, in the mean time is there going to be a solution to the routing problem so that we can have gateways that will route to more than 500 networks? --jon. ------------------------------------------------------------------------- John Romkey (30 Nov 88, ToasterNet) In article <207@logicon.arpa> Makey@LOGICON.ARPA (Jeff Makey) writes: >With 4.2 million network numbers, 115 new network numbers could be >registered every DAY, and it would still take 100 years to exhaust >them all. It seems that there really isn't a problem in the >foreseeable future. Ah, they said that about addresses spaces so many times...it is to cry. I want to see a protocol address space large enough to handle a node in each household appliance, each piece of electronic equipment, and several extras per household, office and vehicle. Traffic lights on the Internet. Stray toasters. And enough addresses left over to scatter hosts across the inner solar system. I'm not very worried about IP running out of addresses here because I'm pretty sure that by the time we start doing all this we'll have learned enough new things about protocols and the devices we're communicating with that we'll have scrapped TCP/IP and gone on to new horizons. Same thing goes for ISO (which there is not a whole lot of 'practical experience' in, anyway). I have a small piece of internet in my dining room. It's not connected to the rest of the world yet (give me another few months), but soon it will spread through the rest of the house. And you can buy a toaster with a microprocessor in it from Sears. No ethernet, yet. - john -- - john romkey romkey@asylum.uucp romkey@xx.lcs.mit.edu romkey@asylum.sf.ca.us Find the cost of freedom, buried in the ground Mother Earth will swallow you, lay your body down. ------------------------------------------------------------------------- Amanda Walker (1 Dec 88, Re: ToasterNet) In article <1010@asylum.sf.ca.us>, romkey@asylum.sf.ca.us (John Romkey) writes: > I want to see a protocol address space large enough to handle a node > in each household appliance, each piece of electronic equipment, and > several extras per household, office and vehicle. Traffic lights on > the Internet. Stray toasters. And enough addresses left over to > scatter hosts across the inner solar system. This reminds me of a remark Gurshuran Sidhu made at an Apple networking conference a couple years ago. He described Ethernet addresses as having been "designed to be intergalactically unique." The biggest problem, I think, is that 32 bits (or 48, or whatever) is certainly big enough to serve as a *physical* addressing scheme, but we keep chopping up addresses so that we can have a *logical* addressing scheme. I mean, we have a Class C address, and we've got a whopping four hosts. That's 1.5% utilization. Of course, it's nice to be able to add hosts as we get them, and subnetting makes contiguous blocks A Good Thing, but it still means that the address space is sparsely populated if you think of it as a physical address space. One advantage that I see IP having over OSI (from what I understand about OSI addressing, anyway), is that the encoding scheme is very simple, thus giving some of the advantages of both physical and logical addressing. I remember the NCP/TCP switchover. It will be a lot harder the next time... -- Amanda Walker ...!uunet!lts!amanda / lts!amanda@uunet.uu.net InterCon, 11732 Bowman Green Drive, Reston, VA 22090 -- "The best way to predict the future is to invent it." -- N. Negroponte