Re: Fully Qualified Domain Name

[Lute Kamstra <Lute.Kamstra@cwi.nl>]

Ralf Muschall <ralf@tecont.de> writes:

> Lute Kamstra <Lute.Kamstra@cwi.nl> writes:
> 
> > "echo $HOSTNAME".  Do you really need to know _your_ domain name?  If
> 
> This just tells you what you types yourself into /etc/HOSTNAME.

I assumed the OP didn't set up his own system.  If he did, he would
probably not ask the questions he is asking.

> It is nontrivial to get the FQDN stuff right for an enduser.  One
> might disable the Message-ID generation in the newsreader.  Then the
> local leafnode will create one.  In order to disable that, one has to
> patch it.  Then the provider's news server will make one, which is
> probably OK.  The problem is that an enduser's computer normally has a
> variable IP and no real name at all ($HOSTNAME is *not* one), since
> it is not DNSed.

Am I missing something?  Why do you need to know, or even have, your
domain name to be able to use Gnus?

> > you want to configure Gnus, you probably only need to know the domain
> > name of your mail server(s) and your news server.  The folks that
> 
> This still does not help perfectly - the thing right of the @ in the
> Message-ID will then be the same as for other users of the same
> provider.  If the provider makes the Message-ID, no problem.  But if
> the left part is made by the users, they might not be unique.

Why do you worry so much about message-ID's?  From the Message manual:

,----
| `Message-ID'
|      This required header will be generated by Message.  A unique ID
|      will be created based on the date, time, user name and system
|      name.  Message will use `system-name' to determine the name of the
|      system.  If this isn't a fully qualified domain name (FQDN),
|      Message will use `mail-host-address' as the FQDN of the machine.
`----

So you don't _need_ to have a FQDN.  What are the chances of the first
part of the ID being the same?  What's the worst that can happen when
the ID's of two different messages are the same?

Lute.

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