Looking on the forum I found how to change the DNS servers only for the wifi networks but I wanted to choose the servers also for mobile data ... I created a script to set up alternate DNS servers / restore original settings.
This script makes a file immutable (chattr +i) and this may cause the OTA update to fail, so before the update OTA 23 I have restored the original settings.
nano /home/phablet/your_path/setdns.sh
and make it executable (chmod u+x)
#!/bin/bash
# Make sure only root can run this script
if [ "$(id -u)" != "0" ]; then
echo " Must be run as root, you must prepend sudo !" 1>&2
exit 1
fi
echo -e '\n - You can set up alternate DNS servers / restore original settings -\n' ;
#
# these are Cloudflare's DNS servers, you can change them with your preferred
dns_one=1.1.1.1
dns_two=1.0.0.1
PS3='Please enter your choice : '
options=("Set new DNS servers" "Roll back your system" "Quit")
select opt in "${options[@]}"
do
case $opt in
"Set new DNS servers")
if grep -qs 'dns=dnsmasq' /etc/NetworkManager/NetworkManager.conf
then
echo -e '\n Remember to "roll back" your system before the next OTA update !\n' ;
# mount root in read/write mode
mount -o remount,rw / ;
# remove /etc/resolv.conf (is a symbolic link pointing to /run/resolvconf/resolv.conf)
rm /etc/resolv.conf ;
# create /etc/resolv.conf
touch /etc/resolv.conf ;
# add it your DNS servers
echo -e "nameserver $dns_one\nnameserver $dns_two" >> /etc/resolv.conf ;
# set permission
chmod 644 /etc/resolv.conf ;
# make it immutable
chattr +i /etc/resolv.conf ;
# replace dns=dnsmasq with dns=none in NetworkManager conf file
sed -i 's/dns=dnsmasq/dns=none/' /etc/NetworkManager/NetworkManager.conf ;
# remount root in read only mode
mount -o remount,ro / ;
echo -e ' Done, DNS servers are set up !\n'
exit 0
else
echo -e '\n Remember to "roll back" your system before the next OTA update !\n' ;
# mount root in read/write mode
mount -o remount,rw / ;
# makes /etc/resolv.conf writable/erasable
chattr -i /etc/resolv.conf ;
# add it your DNS servers
echo -e "nameserver $dns_one\nnameserver $dns_two" > /etc/resolv.conf ;
# make it immutable
chattr +i /etc/resolv.conf ;
# remount root in read only mode
mount -o remount,ro / ;
echo -e ' Done, DNS servers are set up !\n'
exit 0
fi
;;
"Roll back your system")
# mount root in read/write mode
mount -o remount,rw / ;
# makes /etc/resolv.conf writable/erasable
chattr -i /etc/resolv.conf ;
# remove it
rm /etc/resolv.conf ;
# recreate original simbolic link
ln -s /run/resolvconf/resolv.conf /etc/resolv.conf ;
# replace dns=none with dns=dnsmasq in NetworkManager conf file
sed -i 's/dns=none/dns=dnsmasq/' /etc/NetworkManager/NetworkManager.conf ;
# remount root in read only mode
mount -o remount,ro / ;
echo -e '\n Done, DNS settings restored, reboot your device !\n'
exit 0
;;
"Quit")
break
;;
*) echo "invalid option $REPLY"
;;
esac
done
this script sets the Cloudflare's DNS servers, before running it you can change them with your preferred.
cd /home/phablet/your_path
sudo ./setdns.sh
You can check the DNS server used
here
