Newsgroups: comp.os.minix
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!peerfeed.internetmci.com!EU.net!sun4nl!cs.vu.nl!kjb
From: kjb@cs.vu.nl (Kees J Bot)
Subject: Re: 2 questions
Nntp-Posting-Host: hornet.cs.vu.nl
References: <56qiu6$drj@library.clarkson.edu> <56rrvs$d5b@ordeal.cts.com> <E15wq5.9oz@cs.vu.nl> <570421$h09@library.clarkson.edu>
Sender: news@cs.vu.nl
Organization: Fac. Wiskunde & Informatica, VU, Amsterdam
Date: Fri, 22 Nov 1996 10:30:51 GMT
Message-ID: <E19p7G.38L@cs.vu.nl>
Lines: 119

davisoja@craft.camp.clarkson.edu (John Davison) writes:

>My netmask is 2.5.5.192.

Is this short for 255.255.255.192?  A netmask is a lot of 1 bits
followed by 0 bits.  If

	(ip1 & netmask) == (ip2 & netmask)

then ip1 and ip2 are on the same network.

>I have a router set up with a wireless ethernet
>that connects to the school and a copper ethernet that goes out to the
>other computers on my subnet.  Why would the 2.5.5.0 netmask mean they
>gave away their broadcast address?  I could use *.*.*.255 anyway,  
>couldn't I?

The first and last IP address on a network are usually the network
number and the broadcast address.  So your network is x.y.z.192 with
broadcast address x.y.z.255.  If you had been given a range of numbers
on an existing network with the more usual 255.255.255.0 netmask then
you would also have been given the broadcast address of that network.

But now you are in the nice situation of owning your own network.  What
you need to get is your own domain, so you can run your own name server.
Some of our students have gotten their own network to play with,
130.37.14.0/24 (the /24 is the number of 1 bits in the netmask), and
their own domain, pm.cs.vu.nl.

The tables of cs.vu.nl show pm.cs.vu.nl as a subdomain:

	pm		IN	NS	pont
			IN	NS	star

So pont.cs.vu.nl and star.cs.vu.nl are nameservers for pm.cs.vu.nl.  (Get
at least one outside nameserver.)  In /etc/named.boot of the star you
can find:

secondary	pm.cs.vu.nl		130.37.24.8	bak/pmhosts
secondary	14.37.130.IN-ADDR.ARPA	130.37.24.8	bak/public-ADDR

130.37.24.8 is the IP address of pont.cs.vu.nl.  (Pont.cs.vu.nl is still
in the cs.vu.nl domain, because the students got it before they got
their network.)  You have to convince your network administrator to add
a few lines like those above to their tables that point to a machine on
your new network.  Once that is in place you set up you own name server
for your own domain and do whatever you like with it.  It will have to
run Linux or something.  Philip has ported a real name daemon to
Minix-vmd, but I don't have the source yet.

For completeness, below is the /etc/named.boot of pont.cs.vu.nl and the
beginning of the pm.cs.vu.nl and pm.cs.vu.nl.rev files to give you more
inspiration.  I have never set something like this up myself, so check
everything carefully before you make your own tables.  There aren't
many people who know the domain name system inside out, so it won't be
a waste of effort to invest some time into this and "join the elite",
so to speak.
--
	                        Kees J. Bot  (kjb@cs.vu.nl)
	              Systems Programmer, Vrije Universiteit Amsterdam
_._. .._ _   ._ ._.. ___ _. __.   _ .... .   _.. ___ _ _ . _..   ._.. .. _. .
======
/etc/named.boot
======
;
; Boot file for slave name servers for CS.VU.NL
;

directory	/var/named

primary		pm.cs.vu.nl		pm.cs.vu.nl
primary		14.37.130.in-addr.arpa	pm.cs.vu.nl.rev

;
; local secondary zones
;
secondary	vu.nl			130.37.128.4		vu.bak
secondary	cs.vu.nl		192.31.231.42		csvu.bak

; initialize pointers to root name servers
;
cache		.			root.cache
;
======
/var/named/pm.cs.vu.nl
======
@		IN	SOA	pont.cs.vu.nl. abakker.cs.vu.nl. (
				90000063 ;serial 
				900	 ;refresh period
				450	 ;retry refresh
				2419200  ;expiration
				3600	 ;TTL
			)

@		IN	NS	star.cs.vu.nl.
		IN	NS	pont.cs.vu.nl.

pm-net		IN	A	130.37.14.0

eldamar		IN	A	130.37.14.130
		IN	MX	100 veer.cs.vu.nl.
[snip]
======
/var/named/pm.cs.vu.nl.rev
======
; reverse mappings pm.cs.vu.nl
@               IN      SOA     pont.cs.vu.nl. abakker.cs.vu.nl. (
                                90000065 ;serial 
                                900      ;refresh period
                                450      ;retry refresh
                                2419200  ;expiration
                                3600     ;TTL
                        )

@		IN	NS	pont.cs.vu.nl.
		IN	NS	star.cs.vu.nl.

0		IN	PTR	pm-net.pm.cs.vu.nl.
130		IN	PTR	eldamar.pm.cs.vu.nl.
