Re: IP namespace (Was: Re: root knowledge)
yeongw@spartacus.psi.com Wed, 13 May 1992 13:05 UTC
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To: osi-ds@cs.ucl.ac.uk
Subject: Re: IP namespace (Was: Re: root knowledge)
Cc: yeongw@psi.com
Reply-To: osi-ds@cs.ucl.ac.uk
In-Reply-To: Your message of Wed, 13 May 92 10:55:50 +0200. <9205130155.AA00428@beat.aic.co.jp>
Date: Wed, 13 May 1992 08:40:09 -0400
From: yeongw@spartacus.psi.com
> I thought IPs (as representatives of > network nodes) could be hold in the geographical White Pages name space > until recently :-(. The main problem I see with these IP entries is how to > organize the database. > > Let me discuss some alternatives: > > 1) There is one root entry o=IP and immediately below we have all (valid) > IP addresses, each as one object > > 2) Below o=IP we have non-leaf-entries for each IP address group > (according to A, B, C class adresses). [ ... ] Within the proper > class address you'll find all (valid) IP [addresses[ [ ... ] > > 3) We get involved with DNS and build a DNS structure holding domain names > and their IP addresses. But I don't like it very much and see your point, > Wengyik, as given below. All three of these are of valid alternatives, and in fact (2) on a slightly more general scale is what I had in mind. (1) I am inclined to reject because the namespace is too 'flat'. What you're essentially proposing with (1) can have only two consequences depending on how the address space is distributed in reality: - the entire IP address space is held in an entity operated by a single administration. This is nothing more than loading /etc/hosts into the DIT, and for all the same reasons we moved from /etc/hosts to the DNS, we should try to avoid this scheme. - the flat space is carved up with subordinate references into 'pieces' held by several administrations. The likelihood here is that the 'owner' of an IP address (or its designee) will want to hold the 'piece' that corresponds to the IP address (and in fact, should be encourage to do so). This leads to severe fragmentation of a namespace that doesn't have the hierarchical depth to deal with it: there are thousands of IP addresses assigned now. Think what would happen if you had to do a search that had to chase a few thousand subordinate references (which is what this flat namespace essentially requires, modulo any caching/slaving that is being done). (2) is much better (or at least, it is what I had in mind :-)). I'm somewhat puzzled by your characterizing it as an alternative to a separate hierarchy, because if I understood (2) correctly, you've described a separate hierarchy that happens to be rooted at someplace other than the root of the DIT. That's fine: I wasn't suggesting rooting the separate hierarchies under the root of the DIT. To be honest, I haven't given much thought to the problems of representing the IP address space, so I couldn't tell you where I would want to put the separate hierarchies. My personal knee-jerk reaction is that it should go under o=Internet actually (but don't hold me to this :-)). I only have one little quibble with (2) which is that I still think there is insufficient hierarchy. If I understood what you're suggesting in (2) correctly, you're proposing carving up the IP address space into three large subtrees, respectively for class A, B, C addresses. Underneath each 'subtree' is again a large flat space containing all addresses in that class. My objection to the large flat space are the same as in (1). What little thinking I've done on this subject has however been along the lines of (2) except that I want to carve up the namespace into a hierarchy so that subtrees corresponding to a IP network can be delegated to the 'owner' of the network assignment. The 'brute force' method is to borrow from the DNS and carve along the same lines as the INADDR.ARPA space is carved, by network byte components. The problems with doing this is (a) that scheme has a lifetime that will hopefully be measured in months due to the big-internet work on classless, enormously scaleable IP addressing and routing. There are already discussion within the DNS context as to how to carve up INADDR.ARPA in the future, and by going this route, we're essentially investing in a scheme that could easily be obsolete by the time it is deployed. (b) you end up with interior nodes like 192.0.0.0 and 128.0.0.0 which don't really 'belong' to anybody but are instead public resources. This is a minor problem which could easily be handled the same way we're handling the infrastructure between national nodes and organizational nodes (in the case of the U.S. these would be the U.S. state/equivalents and the U.S. counties within states), but is a problem nonetheless. (c) by representing IP addresses by their byte components, some semantic information is lost, for example the fact that 128.1 (just to pick an example) is a network in its own right, and that it is not the case that 128.1 is a subnet of a larger network 128.0.0.0. This only gets worse when the Internet stops 'hard coding' in distinctions between network-component and host-component and starts viewing networks as classless. [That said, this is still closest to the ideal for me, since I can't think of anything better at the momement.] (3) is essentially a suggestion to continue the status quo by pretending that IP addresses are 'special' domain names. This is actually not such a bad idea in my opinion since we already know how to deal with this case. I would like to at least try to do better, since I get the impression that this was a tack-on to the DNS proper to begin with, and had its own problems. Wengyik
- IP namespace (Was: Re: root knowledge) Thomas Johannsen
- Re: IP namespace (Was: Re: root knowledge) yeongw
- Re: IP namespace (Was: Re: root knowledge) William C. Green
- Re: IP namespace (Was: Re: root knowledge) Christian Huitema
- Re: IP namespace (Was: Re: root knowledge) Thomas Johannsen
- Re: IP namespace (Was: Re: root knowledge) Steve Hardcastle-Kille