Maintained by: NLnet Labs

dynamic ip host & auto dns changes

Ernie Luzar
Mon Sep 18 21:05:47 CEST 2017


A. Schulze via Unbound-users wrote:
> 
> Am 18.09.2017 um 14:57 schrieb Ernie Luzar via Unbound-users:
>> Hello list.
>>
>> I have installed the unbound port on Freebsd release 11.1. My host gets
>> an dynamic ip address assigned from the ISP service I am using. This is
>> all very common and normal. But as we all know, the ISP can change not
>> only the assigned ip address on the fly but also the dns servers ip
>> addresses. When this occurs the /etc/resolv.conf file gets updated
>> automatically on the fly.
>>
>> From reading about unbound I get the concept that unbound is designed
>> for hosts that have static ip addresses. IE; the dns ip addresses have
>> to be manually placed in /etc/resolv.conf and will not change without
>> prior written notice.
>>
>> For this usage /etc/resolv.conf get populated with
>> "nameserver 127.0.0.1"
>> and unbound.conf needs the forward-zone: section with the static dns ip
>> addresses.
> 
> which "static dns ip address" do you like to see there?
> 
>> Now my question is, is there any way to configure unbound so when the
>> dynimic dns ip addresses change unbound will contuine to work
>> automatically. IE; no human manual editing of the unbound.conf file.
> simply do no forwarding at all. Let unbound do it's job: 
>  - offer recursiver resolution on 127.0.0.1
>  - resolve names as usual from the root
> You're not required to *use* the ISP's dnsserver even if they are offered.
> 
> Andreas
> 

I think maybe I was un-clear. Most of the original post is describing 
the differences between how the /etc/resolv.conf file is populated based 
on the host having a static or dynamic ip address.

Asking my question a different way.
How doe's unbound interact with the hosts /etc/resolv.conf file?

How do dns requests arriving at the host from the LAN get directed first 
to unbound "local-zone: fqdn always_nxdomain" list and then use the 
"nameservers x.x.x.x" listed in the hosts /etc/resolv.conf file to 
complete the dsn request?

Please provide example of the unbound.conf statements to get this to happen.

Thank you.