Re: [gentoo-user] A DNS question.

[Dan Farrell]

On Sat, 3 Mar 2007 22:04:59 +0100
"Michal 'vorner' Vaner" <vorner@×××.cz> wrote:

> Hello,
>
> On Sat, Mar 03, 2007 at 11:17:52AM -0800, Bob Young wrote:
> > Obviously on a given system each NIC is usually connected to a
> > different domain, my question is, whether or not it
> > is /legal/possible/okay to use different *hostnames* on different
> > NICs?
>
> AFAIK, you can have multiple names for one IP and multiple IPs for one
> name (there are more ways to do that). So, I see no reason why anyone
> would ever forgive you to have different name for each of IP addresses
> your computer has. The other question is if you really want to do
> that, because there might be applications not expecting your computer
> is "schizophrenic" in such way and go nutty.
>
> With regards
>
on the contrary, there are good reasons to have more than one name for
a single computer.  For example, say I have a server 'zeus.mydomain'
that also does mail.  If I name the mailserver 'mail.mydomain' then I
can CNAME that to zeus.mydomain via DNS, or I can just set
mail.mydomain to the ip address of the second interface.  Result - I
can redirect my mail to mail.mydomain and it can go to whatever
computer I desire, whether or not it has different names.  'zeus' is
still listening under that name for other requests.  If i use 'zeus'
for heavy filesharing, I can still get good access over a non-saturated
ethernet device on 'mail'.  

nevertheless, such a thing would really better be accomplished with
ethernet bonding and CNAMEs in dns configuration.  

another, more reasonable situation might be a computer that routed a
few subnets and also provided other services to a subnet or two.  It
might also have an external interface to the ISP, whose hostname on
that network is not up to you.  I don't want to use  "c-24-245-14-14"
as the name for my internet gateway on the inside, do i?  Similarly, on
subnet A it might make perfect sense to call it 'gateway.a.domain' but
perhaps such a computer -- another internet gateway, perhaps? already
uses that name on subnet B.  In that case, imight want to name the same
computer router.b.domain since it routes traffic from b to a.  

make sense?  correct me if i'm wrong ; )
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