DNS newbie requires pointers to good tutorials!

[Herb Martin]

"Andrew Crook" <andrew at NOSPAM_andicrook.demon.co.uk> wrote in message
news:bhr2rb$fm0$1 at sf1.isc.org...
> Thanks
>
> I have since looked at some example configuration files, it doesn't really
> look that bad.
> I will search out the recommended book. there are one or two things I need
> to lookup.e.g.

Then you are better than I am already as I still look something up
almost every day <grin>

> what if your own network number e.g. 192.168.42 used later for reverse
> lookup 42.168.192.in-addr.arpa (from
> http://www.ripe.net/ripe/docs/ripe-192.html example files) is less than
255
> ip addresses etc.

Well, a few clarifications - 192.168.x.y is a private range and must
not be routed on the Internet (won't work anyway) and should not
generally be routed to another organization (unless you have a close
relationship and coordinate the use of these addresses.)

So, if you really mean 192.168.42.y then it doesn't matter; just create
168.192.in-addr.arpa (the entire 192.168.x.y net) and it will include
any address you own -- you only fill in the ones that exist.

If you really mean some public range, then in some (real) sense the
ISPs own those addresses and almost always handle the reverse
zones for them -- if you need an entry for you 1 to a few permanent
entries on the Intenet, you send the ISP an email making the request.
Many times they just put "generic" entries in Host-192.168.12.4 etc.
or Dial-x.y.x to avoid the problem.

> can the ip of the email server be set to a different network eg can my
> friends MX record point to my
> mail server.

Absolutely.  Think about all the email servers in the world that handle
email for multiple companies/organizations...or the ISPs that handle
email for customer DOMAINS outside their own but use the same
email server for all of this.

The Email server (software) should generally use the SAME NAME
as the Reverse will return if someone looks it up -- this might not
have any relationship to the email domains for which it receives mail.
(e.g., My email server has a name but it receives mail for LearnQuick.Com
and HerbMartin.Com and a bunch of other domain names.)

> what if you have groups of ip addresses in different ranges at need to be
> under the same domain.

Forward zones are reverse zones are "technically" unrelated to each other.
So in the forward zone you just put the correct address in there, e.g.,
www.LearnQuick.Com is somewhere in Virginia, but my other machines
abc.LearnQuick.Com are elsewhere and use different ranges of IPs -- all
go in the same forward zone.

Reverse zone records might not even be necessary for many of your
machines -- may be just a wasted of time in 9/10 cases.

> also once a domain is registered are you free to do what you want hostname
> wise.

Within the limits of the RFCs and good judgement (like I wouldn't use
Unicode
names without a "good reason" even though the latest RFCs may make this
legal or my DNS server may support them as they might mess up older DNS
server or client resolution.)

I wouldn't use _underscores in a NetBIOS name nor -dashes in a host name
since I run Windows networks and these legal characters don't work well
on the opposite naming system for machines that have names in both name
spaces.  Also, I won't make a NetBIOS name start with a number just
because it is legal.