My Emailiases: Re: My Emailiases: [Dnsmasq-discuss] multiple
domain support - question
e1-7n32-h2qw-w2h3 at snugmail.com
Mon Aug 4 21:29:21 BST 2008
Simon Kelley (simon at thekelleys.org.uk) (Emailias: REPLY-MASKED) wrote:
> Original Sender: <simon at thekelleys.org.uk>
> Given To: lists.thekelleys.org.uk: Dnsmasq-discuss Info Page
> <--------------------end emailias header-------------------->
> L Forrister wrote:
>> Simon Kelley (simon at thekelleys.org.uk) (Emailias: REPLY-MASKED) wrote:
>>> Original Sender: <dnsmasq-discuss-bounces at lists.thekelleys.org.uk>
>>> Given To: lists.thekelleys.org.uk: Dnsmasq-discuss Info Page
>>> <--------------------end emailias header-------------------->
>>> I have support for multiple domains working, but I've come across a
>>> Consider the case that two different DHCP clients claim the same name.
>>> With the existing code, only one can have it and the current behaviour
>>> is that when a second machine claims a name, the first one loses it.
>>> Now, consider the possibility that the two machines claiming the same
>>> name are in different domains. By default, the existing behaviour must
>>> continue, because the unqualified name is added to the DNS, so that
>>> though the two clients could have "name.domain1.com" and
>>> "name.domain2.com", they are still fighting over just plain "name".
>>> It would be possible to introduce a new mode, which didn't put the
>>> unqualified name into the DNS, and allowed both hosts to keep their
>>> as long as they are in different domains. Would that be useful, or just
>>> an confusing complication?
>> I don't see anything confusing about it. What good is multiple domain
>> support if you're forced to maintain unique host names across all
>> I've never quite understood why dnsmasq can't allow the duplicate names
>> in the first place. Why must it be so. Consider a client machine
>> with two interfaces. Both dhcp. They'll both get leases. Both ip's
>> will be active. But the dns will only return one (name and ip)
>> depending on which was most recently renewed. But its not just the
>> dns, because when you check the leases file there's only one lease
> The reason is simply that there's no way to differentiate the "plain"
> unqualified versions of the name, without the domain part. To make the
> multiple names work would mean suppressing unqualified names. For most
> people, having them is more usefull that having multiple domains.
As far the leases file is concerned, doesn't the mac address (and/or the
client id) provide that differentiation? I mean, having the same
unqualified host name on two separate leases would not cause identical
lines/records in the lease file.
The dns code, seems not to have a problem with multihomed hosts in
either /etc/hosts or /etc/dnsmasq.hosts (my dnsmasq addn-hosts file.)
lf$ dig +short -x 192.168.160.67 -x 192.168.160.68 -x 192.168.160.69
lf$ dig +short alkix.rebel.lan
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