[Gllug] BIND zone file question

[Ian Northeast]

Matthew King wrote:
> 
> > Applying for a linux job at the moment, and got sent a test to check
> > how resourceful
> > I am. One of the questions is spot the errors in the following zone
> > file:
> >
> > @   IN  SOA ns0.example.org.  hostmaster.example.org. (
> >                    2001103101  ;   Serial
> >                    28800       ;   Refresh
> >                    7200        ;   Retry
> >                    604800      ;   Expire
> >                    3600 )      ;   TTL Minimum
> > @   IN  A       212.111.16.78
> > @   IN  NS      ns0.example.org.
> > @   IN  NS      ns1.example.org.
> > @   IN  MX  10  mail.example.org
> >
> > I spotted a missing fullstop at the end of the MX record making the
> > hostname relative to the origin,
> > and also that ns1 should be specified as an ip-address.
> > Dont like the look of the "@" origin symbols at the start of each line,
> > but this is valid syntax and the same
> > as leaving all RR domains blank.
> > Any other errors ?
> >
> > /Anthony/
> 
> Well the retry/expire/etc. look a bit small, but I guess that's really up to
> the hostmaster.

2 hours/7 days - within guidelines. I too would tend to make them a bit
bigger. 

> Incidentally NS records are not IP addresses. NS records are given IP
> addresses with normal A records later.

Which are missing - you need them both.
 
> Of course there's only one MX, which usually bad :-)

But not illegal. However, there is no A for mail.example.org.

$TTL is missing from the top and there is no TTL on the SOA. This is
actually the only fatal error - i.e. which would stop the zone from
loading at all (as opposed to working properly). I cheated and ran it
through named-checkzone - but I guess this could be defined as
"resourceful".

It is normal to add a localhost RR too.

Of course we are all assuming that this zone file is for domain
example.org but this wasn't actually specified:) Having
"ns0.example.org." in the SOA doesn't imply that this is the domain
name. This is specified in the "zone" clause in named.conf which names
this file (there can be more than one domain running off the same file
too).

At least there's no "CNAME and other data" in there. If I'd been posing
the question I would have added one, just to be a bastard:)

Ian

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