RE: tlug: Re: tlug.linux.or.jp

[TBaetzle@example.com]

> Craig Oda wrote:
> On Sat, 28 Mar 1998, Ken Harada wrote:
> > Have you noticed the very quick action of Ogochan, chairman
> > of JLUG, on setting the tlug.linux.or.jp DNS setting.
> 
> Yes, Ogochan from JLUG really helped on that one.  :-)  
> 
> > (There seems additional setting required at our end? or 
> > riccia dns for mail to craigoda@example.com reachable.)
> 
> Is this the secondary DNS setting?  Maybe Thomas or Scott Stone
> can do it for us?
> 
I've just checked, and tlug.linux.or.jp is just an 
"A" record in the linux.or.jp domain. Do you think 
that the JLUG would have a problem with giving us
the whole tlug.linux.or.jp subdomain? This would
require that we set up a primary DNS for that zone,
and possibly one or more secondaries. It would
also require a change in the linux.or.jp zone file.

The advantage would be that we could add more
names/addresses below tlug.linux.or.jp when the
need arises.

> I'm not exactly sure how the DNS system works. 
> 
Let me try and explain: The DNS is a distributed database.
Think of the DNS name space as an inverted tree; built 
top-down by reading DNS names from back to front. The 
root of that tree is actually a blank label. 

Here's a small sideways projection showing some
branches of the tree.

""+--"jp"--+--"or"--+--"linux"--+--"tlug"
  |        |
  |        +--"co"--+--"pht"--+--"ume"
  |                 |         |
  |                 |         +--"tlug"
  |                 |          
  |                 +--"sega"--+--"www"
  |                 
  +--"de"--+--"inovis"--+--"ns"
                        |
                        +--"www"

Any node in the tree complete with all the nodes below it
is basically a domain with its subdomains. The "pht" node
and the nodes right to it in the graph denote the 
pht.co.jp domain, which in turn is a subdomain of the 
co.jp domain.

The "zone" is another important term in DNS speak. A zone
is basically the range of authority of a nameserver. The
pht.co.jp domain for example has currently one primary
nameserver, ume.pht.co.jp, that holds the data on all
names in that domain. In this case, the zone and the
domain are the same. If we wanted to start to add names
below tlug.pht.co.jp, we could add them to the pht.co.jp
zone, or we could delegate a new zone, tlug.pht.co.jp.
This is done by adding a reference in the pht.co.jp zone
which points to the name servers that server this new 
zone. In such a case, the pht.co.jp domain would have
two zones.

The DNS works by having a defined set of "root servers"
at the top (defined in the root.zone file of the name
server) which delegates all the top level domains. These
servers then delegate the second level domains (like
co.jp for example), and so on.

So if I query for tlug.pht.co.jp on my machine, I ask
my nameserver to tell me about tlug.pht.co.jp. Assuming
that it doesn't have the answer cached, it starts by
asking one of the root servers about the name servers
for the jp zone. Once it knows the jp servers, it
starts to look for the co.jp servers, and then the
pht.co.jp servers, which should lead to the answer
eventually. And since the server caches the answers
it got on the way, it doesn't have to make such a
complicated query all the time ;-)  

So back to the topic of setting up tlug.linux.or.jp
on our machine. We'd need a zone file for the new
domain, like this:

-8<--($NAMEDROOT/db.tlug.linux.or.jp)--
$ORIGIN tlug.linux.or.jp.
@ IN SOA tlug.pht.co.jp. hostmaster.tlug.pht.co.jp. (
                        1998032801 ;serial
                        86400      ;refresh
                        7200       ;retry
                        604800     ;expire
                        86400 )    ;minim

                IN      NS      tlug.pht.co.jp.
                IN      NS      ns.inovis.de.
                IN      NS      ume.pht.co.jp.
                IN      MX      10 tlug.pht.co.jp.

; hosts in this domain
@               IN      CNAME   tlug.pht.co.jp.
www             IN      CNAME   tlug.pht.co.jp.
-8<----

In $NAMEDROOT/boot.zones, we'd add the zone file
by adding the line

-8<----
primary tlug.linux.or.jp db.tlug.linux.or.jp
-8<----

On ume.pht.co.jp and ns.inovis.de, Scott and I
each add in boot.zones

-8<----
secondary tlug.linux.or.jp 210.145.37.187 sdb.tlug.linux.or.jp
-8<----

Finally, Ogochan should change the tlug record
in the linux.or.jp zone file on riccia to

-8<----
tlug	IN	NS	tlug.pht.co.jp.
	IN	NS	ns.inovis.de.
	IN	NS	ume.pht.co.jp.	
-8<----

This is the delegation of the authority over the
tlug.linux.or.jp domain to our servers. From now
on, all changes in that domain made on the tlug
machine will be mirrored within a day by ume and
ns.inovis.de.

Did I scare anybody off? Sorry! Of course this
is a very incomplete and terse summary - but if
you want to know more, you can always ask, and
I'll try and elaborate. I've got a longer 
explanation available that was done as a part of 
my thesis, but unfortunately it's in German :-( 
PostScript with illustrations are available on 
request :-)

HTH,
Thomas




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