[TriLUG] Ignoring certain DHCP options (specifically, DNS)

[David Both]

I just add the following lines to ifcfg-<interfacename> files:

DNS1=8.8.8.8
DNS2=8.8.4.4
DNS3=whatever other DNS you want to use.

Three is the magic number.

Works like a charm.

You can also add the DNS entries to your dhcpd.conf file subnet definition stanza.

     option domain-name-servers      192.168.0.52, 8.8.8.8;

Using your own choice of name servers.

On 02/19/2013 10:43 AM, Aaron Schrab wrote:
> At 09:57 -0500 19 Feb 2013, Brian Henning <bhenning at pineinst.com> wrote:
>> So my question is: Is creating a dhclient.conf the only right solution to
>> tell dhclient to ignore DNS info from DHCP and leave my resolv.conf alone?
>
> The method I've used for a quick way to prevent dhclient from modifying my
> resolv.conf file is to just run `chattr +i /etc/resolv.conf` as root.  This
> marks the file as being immutable, and will prevent even programs running with
> root privileges from modifying it unless the immutable flag is first removed,
> which can be done by simply substituting '-' for '+' in the chattr command.
>
> This does result in an error being displayed when the script started by
> dhclient attempts to replace that file, but as far as I've been able to tell
> it doesn't cause any actual problems.

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David P. Both



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David P. Both, RHCE
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