Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!cs.utexas.edu!uwm.edu!bionet!agate!ucbvax!SH.CS.NET!jcurran From: jcurran@SH.CS.NET (John Curran) Newsgroups: comp.protocols.tcp-ip.domains Subject: Re: Subnets and IN-ADDR.ARPA Message-ID: <9104102331.AA18849@ucbvax.Berkeley.EDU> Date: 10 Apr 91 13:54:48 GMT References: Sender: daemon@ucbvax.BERKELEY.EDU Distribution: inet Organization: The Internet Lines: 57 -------- From: Rob Burrowes > 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. > > 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. Always fun. Presuming that you're using a 255.255.255.0 subnet mask, then you can delegate nameservice for each associated 216.130.IN-ADDR.ARPA subdomain to cs.aukuni.ac.nz. In the zone file for 216.130.IN-ADDR.ARPA on aukuni.ac.nz: 32 IN NS cs.aukuni.ac.nz. 33 IN NS cs.aukuni.ac.nz. 34 IN NS cs.aukuni.ac.nz. 35 IN NS cs.aukuni.ac.nz. 36 IN NS cs.aukuni.ac.nz. 37 IN NS cs.aukuni.ac.nz. 38 IN NS cs.aukuni.ac.nz. 39 IN NS cs.aukuni.ac.nz. and then setup cs.aukini.ac.nz as primary for each of these subdomains and create the appropriate zone files. You should not make cs.aukini.ac.nz a primary for the 216.130.IN-ADDR.ARPA domain, but only the subdomains: In the named.boot file for cs.aukini.ac.nz: primary 32.216.130.IN-ADDR.ARPA named.cs-32-inaddr.db primary 33.216.130.IN-ADDR.ARPA named.cs-33-inaddr.db primary 34.216.130.IN-ADDR.ARPA named.cs-34-inaddr.db ... If you are using a subnet mask of less than 24 bits, this system will still work (although you have delegate multiple IN-ADDR domains for each IP subnet). If you are using a subnet mask with greater than 24 bits, then each IN-ADDR delegation actually reflects a "block" of IP subnets; hopefully, the IP subnets have been passed out in matching blocks.. :-) > What is the line "sortlist 10.0.0.0" in the named.boot file for? I couldn't > see any doc which would tell me. (It was in an example named.boot file). There's a few words regarding the sortlist directive in man/named.8. It is used to order in which A records appear in replies. If you have multiple IP addresses on many hosts, you may use sortlist to encourage the world to use interfaces on one network over another. /John