Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!usc!snorkelwacker.mit.edu!bloom-beacon!eru!hagbard!sunic!mcsun!cernvax!chx400!chx400!bernina!karrer From: karrer@bernina.ethz.ch (Andreas Karrer) Newsgroups: comp.protocols.tcp-ip.domains Subject: Re: Subnets and IN-ADDR.ARPA Keywords: subnets IN-ADDR.ARPA Message-ID: <1991Apr11.090926.24784@bernina.ethz.ch> Date: 11 Apr 91 09:09:26 GMT References: Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH Lines: 32 rob@cs.aukuni.ac.nz (Rob Burrowes ) writes: >Our domain is cs.aukuni.ac.nz and the server(s) look after addresses >130.216.32.x through 130.216.39.x. These being subnets 32 - 39 of 130.216. I assume your subnet mask is 255.255.255.0. >The domain aukuni.ac.nz is looks after all other subnets of 130.216. >My problem is obtaining the hostname from the address using the IN-ADDR.ARPA >domain. How do we tell aukuni.ac.nz's BIND server and our BIND server that >request for the hostname of say 130.216.34.2 should be directed to the >cs.aukuni.ac.nz. server while requests for 130.216.1.2 should be handled by >the aukuni.ac.nz server. Currently aukuni.ac.nz's server attemps to handle >such requests and of course fails. The problem is that the DNS has no concept of IP subnetting. I guess in your case you could have a SOA field for each subnet, e.g. the cs.aukuni.ac.nz servers would have 8 SOA RR's as in: $ORIGIN 32.216.130.in-addr.arpa. @ IN SOA .... in their reverse tables, whereas the aukuni.ac.nz servers would have authority SOA RR's for the other 246 subnets. Clumsy, but manageable. But then, what do you do if your subnet mask is 255.255.255.192 as ours? +----------- Andi Karrer, Communication Systems, ETH Zuerich, Switzerland karrer@bernina.ethz.ch karrer@czheth5a.bitnet /S=karrer/OU=bernina/O=ethz/PRMD=SWITCH/ADMD=ARCOM/C=CH/