Hi,

Gonzalo Pérez de Olaguer Córdoba <salo@???> writes:

> Hi, everybody here.
>
> El Tue, 18 Mar 2025 16:44:03 -0300
> altoid via Dng <dng@???> escribió:
>
>> Then, while searching on how to fix something else, I came across
>> [/sbin/dhclient-script] and within it, this bit which instantly
>> called my attention:
>>

>> [code]
>> --- snip ---
>> # update /etc/resolv.conf based on received values    # <---- wthf?
>>   make_resolv_conf() {
>>       local new_resolv_conf
>> --- snip --- 
>> [/code]

>>
>> Not in any way script savvy but it seemed I had found the hijacker,
>> so to speak.
>>
>> Those who know more could confirm my suspicions.
>
> Take a look at the manual page for dhclient-script(5)

Add dhclient.conf(5) for good measure. Looks like commenting out

prepend domain-name-servers 127.0.0.1;

(substitute whatever IP address scratches you itch) would do the trick.

> I have this script at /etc/dhcp/dhclient-enter-hooks.d/no_dns_update
> (any name will do) that overrides the make_resolv_conf function that
> you don't like:
>
> --- start
> #!/bin/sh
>
> # prevent dhclient from updating /etc/resolv.conf
> make_resolv_conf() { : ; }
> --- end

I use a similar approach to inject *additional* variables for things
that the DHCP server at the office doesn't provide, e.g. NTP servers
(as the default ones are blocked by the firewall).

> I suppose this works, althought I have set /etc/resolv.conf immutable anyway
> because over the years I have found LOTS of programs destroying my
> settings :-)
>
> Hope it helps.
> Salo.

Me too.
--
Olaf Meeuwissen