Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!spider.co.uk!keith From: keith@spider.co.uk (Keith Mitchell) Newsgroups: comp.protocols.tcp-ip Subject: Re: Naive questions about subnets & domains Message-ID: <8908181610.AA28277@orbweb.spider.co.uk> Date: 18 Aug 89 16:10:19 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 66 I believe the solution which puts international subsidiaries into subdomains of the country they are in is not, in general at least, the correct solution. My understanding is that the the domain name space reflects an *organisational* not geographical, hierarchy. It is thus valid to have sites which are in another country be subdomains of the parent company that is a sub-domain in its own country. i.e. We are "spider.co.uk". We have US and French subsidaries, which are "boston.spider.co.uk" and (soon) "paris.spider.co.uk" . These are sub-organisations within the bigger spider organisation, and the names reflect the organisational heirarchy. I would say that ".convex.oxford.ac.uk" is invalid, as a company cannot be part of Oxford University in its role as part of the UK Academic Community. For spider, mail routing works because our only point of contact with the external world is a UK site, international delivery is an internal operation. Now, if our international subsdiaries had their own links to the outside world, in the country they are geographically located in, then it would be appropriate for them to be registered in that country's domain (e.g. spider.com and spider.fr). Without the external links in the relevant country, routing which is done on top-level domains will get confused. i.e. If we were to register our US site as spider.com, someone in the UK mailing this would have it routed to a US backbone site that knows about .com, which would know you get to Spider via the UK, so back it goes. Whether the internal and external links use UUCP, the Internet or damp string is actually irrelvant to naming. So, I think the general rule is to register a site as a sub-domain of the country its mail link to the outside world is in. This does not preclude registering a site more than once. What we would ideally like is to have a domain ".spider", which all our machines and sites are in from an internal point of view. This would be registered as a sub-domain of all necessary countries, with an external mail link in each of them. Thus, edinburgh.spider.com, boston.spider.fr, and paris.spider.co.uk are all valid, the top level domain merely dictating the point of entry to our internal mail system, and the bottom one where it finishes up. This fits in with global mail routing based on domains. Is this sensible ? Does the domain name system permit the same entity appearing in distinct sub-domains, or have I the wrong end of the stick ? I better make it clear that the above represents my current thoughts on this topic, rather than any offically decided company policy. Keith Mitchell Spider Systems Ltd. Spider Systems Inc. Spider Park 12 New England Executive Park Stanwell Street Burlington Edinburgh, Scotland MA 01803 +44 31-554 9424 +1 (617) 270-3510 keith@spider.co.uk keith%spider.co.uk@uunet.uu.net ...!uunet!ukc!spider!keith keith%uk.co.spider@nsfnet-relay.ac.uk