CentOS - Dec 2019 - midco stealling searches, was browsers slowing Centos 7 installation to a crawl

On Mon, Dec 02, 2019 at 06:51:44PM -0600, Michael Hennebry
wrote:
> I've chacked on that.
> I've made what seemed like promissing changes to
> /etc/sysconfig/network-scripts/ifup-post and
> /etc/sysconfig/network-scripts/network-functions .
> No go.
> I still get the search line in resolv.conf .
> I've tried putting in search google.com ,
> but on reboot, it still gives me midco and only midco .
> 
> Any idea what does affect search in resolv.conf ?
> How can I fix this so I do not have to
> manually edit resolv.conf after each reboot.
Neither of those files are the correct files to edit.

You want to edit the ifcfg-<interface name> file (replace
<interface name> with the name of the network interface) and add
PEERDNS=no in the file.  This will make it so DHCP doesn't overwrite
the resolv.conf.

If you just want to hard-code DNS servers, you can either do that in
your networkmanager configuration, or add DNS1=9.9.9.9 to the ifcfg
file.  You can add a second IP with DNS2=1.1.1.1, too.  Use whatever
DNS IPs you want.

This is documented in /usr/share/doc/initscripts-*/sysconfig.txt

-- 
Jonathan Billings <billings at negate.org>

On Tue, 3 Dec 2019, Jonathan Billings wrote:
> On Mon, Dec 02, 2019 at 06:51:44PM -0600, Michael Hennebry wrote:
>> Any idea what does affect search in resolv.conf ?
>> How can I fix this so I do not have to
>> manually edit resolv.conf after each reboot.
>
> Neither of those files are the correct files to edit.
>
> You want to edit the ifcfg-<interface name> file (replace
> <interface name> with the name of the network interface) and add
> PEERDNS=no in the file.  This will make it so DHCP doesn't overwrite
> the resolv.conf.
I only have ifcfg-lo , which I am pretty sure is the loopback interface.
As expected, other files suggest eth0 is my ethernet connection.
Should I add a one-line ifcfg-eth0 file?
> If you just want to hard-code DNS servers, you can either do that in
> your networkmanager configuration, or add DNS1=9.9.9.9 to the ifcfg
> file.  You can add a second IP with DNS2=1.1.1.1, too.  Use whatever
> DNS IPs you want.
What I want is to keep midco from hijacking searches.
Keeping midco's DHCP from adding a search line
to resolv.conf seems to be the key.

I'll hard-code DNS servers if I have to,
but that is not the point of this.

Currently I have
# Generated by NetworkManager
# search midcoip.net
nameserver 2001:48f8:3004:2ce:5a19:f8ff:fe9e:a4bc
nameserver 192.168.0.1

My understanding is that the network manager
generates resolv.conf and DHCP edits it.
Does the network manager include nameservers?
Would putting PEERDNS=no in a ifcfg-eth0 file
result in an empty resolv.conf ?
I realize I could just try it and see,
but I do not know how much damage I could do if I mess it up.
> This is documented in /usr/share/doc/initscripts-*/sysconfig.txt
I have /usr/share/doc/initscripts-9.49.47/sysconfig.txt only.

-- 
Michael   hennebry at web.cs.ndsu.NoDak.edu
"Sorry but your password must contain an uppercase letter, a number,
a haiku, a gang sign, a heiroglyph, and the blood of a virgin."
                                                              --  someeecards

On Tue, Dec 03, 2019 at 01:17:53PM -0600, Michael Hennebry
wrote:
> I only have ifcfg-lo , which I am pretty sure is the loopback interface.
> As expected, other files suggest eth0 is my ethernet connection.
> Should I add a one-line ifcfg-eth0 file?
If you are using ethernet (and not a wireless device or some other
internet connectivity) you should have an ifcfg- file for the
interface.  Look at the output of 'ip link' to see all the interfaces
you have configured.
> Currently I have
> # Generated by NetworkManager
> # search midcoip.net
> nameserver 2001:48f8:3004:2ce:5a19:f8ff:fe9e:a4bc
> nameserver 192.168.0.1
> 
> My understanding is that the network manager
> generates resolv.conf and DHCP edits it.
> Does the network manager include nameservers?
> Would putting PEERDNS=no in a ifcfg-eth0 file
> result in an empty resolv.conf ?
> I realize I could just try it and see,
> but I do not know how much damage I could do if I mess it up.
Since there's no ifcfg file, I suspect you're using NetworkManager to
manage your network.  Run 'nmcli con' to get a list of your network
connections, and then run 'nmcli con edit "Connection Name"'
(replace
"Connection Name" with the name of your ethernet connection).  You can
then set ipv4.ignore-auto-dns to 'yes' and then set ipv4.dns and
ipv4.dns-search.  This should override what DHCP sets.
> > This is documented in /usr/share/doc/initscripts-*/sysconfig.txt
> 
> I have /usr/share/doc/initscripts-9.49.47/sysconfig.txt only.
I used the * as a glob, not a literal character.

-- 
Jonathan Billings <billings at negate.org>