Change DNS servers, wifi and mobile data

[Br1]

--------- UPDATE ---------
New version to install/uninstall with single command, see here for further information.

You can set alternative dns servers and restore the default settings in an easy way, reboot not required.

You can switch between two preset providers or enter the one you prefer.

three steps :

1 - download (just click) set-dns.1.01.tar.gz from here

2 - open file manager, go to Downloads, click set-dns.1.01.tar.gz and extract archive

3 - open terminal and type :

sudo Downloads/set-dns.1.01/setdns.sh

You will see this :

type 1 to set Cloudflare servers
type 2 to set OpenDNS servers
type 3 to set your preferred servers (*)
type 4 to restore default settings (Restore OS)
type 5 to exit (OS unchanged)

Remember to "Restore OS" before the next OTA update !

Preview :

#!/bin/bash

# Make sure only root can run this script
if [ "$(id -u)" != "0" ]; then
   echo " - You must prepend 'sudo' !" 1>&2
   exit 1
fi

echo -e '\n- Set DNS servers / Restore default -\n' ;

# these are Cloudflare's DNS servers
CLF_one=1.1.1.1
CLF_two=1.0.0.1

# these are OpenDNS servers
OPE_one=208.67.222.222
OPE_two=208.67.220.220

PS3='
Please enter your choice : '
options=(" Cloudflare" " OpenDNS" " Custom DNS" " Restore OS" " Quit")
select opt in "${options[@]}"
do
	case $opt in
	" Cloudflare")
		# search the default string
		if grep -qs 'dns=dnsmasq' /etc/NetworkManager/NetworkManager.conf

		then

			# -------------------- runs if found default dns settings -------------------- 

			# 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 Cloudflare servers
			echo -e "nameserver $CLF_one\nnameserver $CLF_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 '\n Cloudflare DNS are set up !\n'

			exit 0

		else

			# -------------------- runs if dns settings are already changed --------------------

			# mount root in read/write mode
			mount -o remount,rw / ;

			# makes /etc/resolv.conf writable/erasable
			chattr -i /etc/resolv.conf ;

			# add it Cloudflare servers
			echo -e "nameserver $CLF_one\nnameserver $CLF_two" > /etc/resolv.conf ;

			# make it immutable
			chattr +i /etc/resolv.conf ;

                       # remount root in read only mode
                        mount -o remount,ro / ;

			echo -e '\n Cloudflare DNS are set up !\n'

			exit 0

		fi

		;;

	" OpenDNS")
		# search the default string
		if grep -qs 'dns=dnsmasq' /etc/NetworkManager/NetworkManager.conf

		then

			# -------------------- runs if found default dns settings -------------------- 

			# 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 OpenDNS servers
			echo -e "nameserver $OPE_one\nnameserver $OPE_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 '\n OpenDNS Servers are set up !\n'

			exit 0

		else

			# -------------------- runs if dns settings are already changed --------------------

			# mount root in read/write mode
			mount -o remount,rw / ;

			# makes /etc/resolv.conf writable/erasable
			chattr -i /etc/resolv.conf ;

			# add it OpenDNS servers
			echo -e "nameserver $OPE_one\nnameserver $OPE_two" > /etc/resolv.conf ;

			# make it immutable
			chattr +i /etc/resolv.conf ;

                       # remount root in read only mode
                        mount -o remount,ro / ;

			echo -e '\n OpenDNS Servers are set up !\n'

			exit 0

		fi

		;;

	" Custom DNS")
		# search the default string
		if grep -qs 'dns=dnsmasq' /etc/NetworkManager/NetworkManager.conf

		then

			# -------------------- runs if found default dns settings -------------------- 

			# 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 ;

                                        read -p " Type primary server : " priDN

					echo -e "nameserver $priDN" > /etc/resolv.conf ;

					read -p " Type secondary server : " secDN

					echo -e "nameserver $secDN" >> /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 '\n Custom DNS are set up !\n'

			exit 0

		else

			# -------------------- runs if dns settings are already changed --------------------

			# mount root in read/write mode
			mount -o remount,rw / ;

			# makes /etc/resolv.conf writable/erasable
			chattr -i /etc/resolv.conf ;

                                        read -p " Type primary server : " priDN

                                        echo -e "nameserver $priDN" > /etc/resolv.conf ;

                                        read -p " Type secondary server : " secDN

                                        echo -e "nameserver $secDN" >> /etc/resolv.conf ;


			# make it immutable
			chattr +i /etc/resolv.conf ;

                       # remount root in read only mode
                        mount -o remount,ro / ;

			echo -e '\n Custom DNS are set up !\n'

			exit 0

		fi

		;;

	" Restore OS")
			# 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 / ;

                       # restart daemon
                        service network-manager restart ;

			echo -e '\n Default settings have been restored !\n'

			exit 0

		;;
        " Quit")
			echo -e '\n OS unchanged !\n'

			break
		;;
			*) echo "invalid option $REPLY"
		;;
    esac
done

(*) For example, if you want to set Google DNS servers enter 8.8.8.8 as primary server and 8.8.4.4 as secondary server.

[Br1]

OTA-25 --- You can reinstall, it works.

[Keneda]

@Br1
Did you consider building an app for your 3 scripts to be nooby friendly ?

[kimo]

@Br1 As he said, Keneda if you can building an app, this would be great. I tried it on focal. It worked with me in the first time, and when I tried to return to restore default settings, I lost my connection to the Internet without finding a solution, despite my attempts to fix it, which forced me to re-install UT

[Br1]

@Keneda I can't promise anything but I will try.

[Keneda]

@Br1
I don't know if you saw my post responding to you on another of your thread so i put link here, it may be helpfull : https://forums.ubports.com/topic/8144/how-to-record-calls/4?_=1680905394718

[Br1]

@Keneda to build apps it is necessary to know qml and python and I don't know them "Touch IDE" is an interesting app, but I would like to do something with shell scripting

[domubpkm]

This post is deleted!

[Br1]

@domubpkm said in Change DNS servers, wifi and mobile data:

@Br1 typo error

fixed, thank you.

[domubpkm]

This post is deleted!

[Br1]

---- UPDATE OTA-2 Focal ----
---- Stable Channel ----

Usual three steps :

1 - download (just tap) setdns-ota.2 from here

2 - open file manager, go to Downloads, tap setdns-ota.2.tar.gz and tap extract archive

3 - open terminal, type :

sudo Downloads/setdns-ota.2/setdns-ota.2.sh

and hit enter,

type 1 + enter to set Cloudflare servers
type 2 + enter to set OpenDNS servers
type 3 + enter to set custom servers (*)
type 4 + enter to restore default settings (Restore OS)
type 5 + enter to exit (OS unchanged)

Remember to "Restore OS" before the next OTA update !

set-dns is one single script, preview :

#!/bin/bash

# Make sure only root can run this script
if [ "$(id -u)" != "0" ]; then
   echo " - You must prepend 'sudo' !" 1>&2
   exit 1
fi

echo -e '\n- Set DNS servers / Restore default -\n' ;

rsv_cnf=/etc/resolv.conf ;

# these are Cloudflare's DNS servers
CLF_one=1.1.1.1
CLF_two=1.0.0.1

# these are OpenDNS servers
OPE_one=208.67.222.222
OPE_two=208.67.220.220

PS3='
Please enter your choice : '
options=("  Cloudflare  -      " "  OpenDNS     -      " "  Custom DNS  -      " "  Restore OS  -      " "  Quit        -      ")
select opt in "${options[@]}"
do
	case $opt in
	"  Cloudflare  -      ")
		# check resolv.conf
		if [ ! -L $rsv_cnf ] ;

		then

			# -------------------- runs if resolv.conf is a file --------------------

			# mount root in read/write mode
			mount -o remount,rw / ;

			# add it Cloudflare servers
			echo -e "# Cloudflare servers" > $rsv_cnf ; echo -e "nameserver $CLF_one" >> $rsv_cnf ; echo -e "nameserver $CLF_two" >> $rsv_cnf ;

			# remount root in read only mode
			mount -o remount,ro / ;

			echo -e '\n Cloudflare DNS are set up !\n'

			exit 0

		else

			# -------------------- runs if resolv.conf is a symbolic link --------------------

			# mount root in read/write mode
			mount -o remount,rw / ;

			# delete symbolic link
			rm /etc/resolv.conf ;

			# create file
			touch /etc/resolv.conf ;

			# add it Cloudflare servers
			echo -e "# Cloudflare servers" > $rsv_cnf ; echo -e "nameserver $CLF_one" >> $rsv_cnf ; echo -e "nameserver $CLF_two" >> $rsv_cnf ;

                       # remount root in read only mode
                        mount -o remount,ro / ;

			echo -e '\n Cloudflare DNS are set up !\n'

			exit 0

		fi

		;;

	"  OpenDNS     -      ")
		# check resolv.conf
		if [ ! -L $rsv_cnf ] ;

		then

			# -------------------- runs if resolv.conf is a file --------------------

			# mount root in read/write mode
			mount -o remount,rw / ;

			# add it Cloudflare servers
			echo -e "# OpenDNS servers" > $rsv_cnf ; echo -e "nameserver $OPE_one" >> $rsv_cnf ; echo -e "nameserver $OPE_two" >> $rsv_cnf ;

			# remount root in read only mode
			mount -o remount,ro / ;

			echo -e '\n OpenDNS servers are set up !\n'

			exit 0

		else

			# -------------------- runs if resolv.conf is a symbolic link --------------------

			# mount root in read/write mode
			mount -o remount,rw / ;

			# delete symbolic link
			rm /etc/resolv.conf ;

			# create file
			touch /etc/resolv.conf ;

			# add it Cloudflare servers
			echo -e "# OpenDNS servers" > $rsv_cnf ; echo -e "nameserver $OPE_one" >> $rsv_cnf ; echo -e "nameserver $OPE_two" >> $rsv_cnf ;

                       # remount root in read only mode
                        mount -o remount,ro / ;

			echo -e '\n OpenDNS servers are set up !\n'

			exit 0

		fi

		;;

	"  Custom DNS  -      ")
		# check resolv.conf
		if [ ! -L $rsv_cnf ] ;

		then

			# -------------------- runs if resolv.conf is a file -------------------- 

			# mount root in read/write mode
			mount -o remount,rw / ;

			echo -e "# Custom DNS servers" > $rsv_cnf ; 

                                        read -p " Type primary server : " priDN

					echo -e "nameserver $priDN" >> $rsv_cnf ;

					read -p " Type secondary server : " secDN

					echo -e "nameserver $secDN" >> $rsv_cnf ;

			# remount root in read only mode
			mount -o remount,ro / ;

			echo -e '\n Custom DNS are set up !\n'

			exit 0

		else

			# -------------------- runs if resolv.conf is a symbolic link --------------------

			# mount root in read/write mode
			mount -o remount,rw / ;

			# delete symbolic link
			rm /etc/resolv.conf ;

			# create file
			touch /etc/resolv.conf ;

			echo -e "# Custom DNS servers" > $rsv_cnf ;

                                        read -p " Type primary server : " priDN

                                        echo -e "nameserver $priDN" >> $rsv_cnf ;

                                        read -p " Type secondary server : " secDN

                                        echo -e "nameserver $secDN" >> $rsv_cnf ;

                       # remount root in read only mode
                        mount -o remount,ro / ;

			echo -e '\n Custom DNS are set up !\n'

			exit 0

		fi

		;;

	"  Restore OS  -      ")
			# mount root in read/write mode
			mount -o remount,rw / ;

			# delete file
			rm /etc/resolv.conf ;

			# recreate symbolic link
			ln -s /run/systemd/resolve/stub-resolv.conf /etc/resolv.conf ;

                       # remount root in read only mode
                        mount -o remount,ro / ;

			echo -e '\n Default settings have been Restored !\n'

			exit 0

		;;
        "  Quit        -      ")
			echo -e '\n  - OS unchanged !\n'

			break
		;;
			*) echo "invalid option $REPLY"
		;;
    esac
done

(*) For example, if you want to set Google DNS servers enter 8.8.8.8 as primary server and 8.8.4.4 as secondary server.

[domubpkm]

@Br1 Hello. is your OTA-2 work / procedure the same for OTA-3 ? Thanks again

[Br1]

I can’t test ota 3 update, install at your own risk (*)

[Br1]

OTA 3 Stable channel --- You can reinstall, no changes are necessary.

[domubpkm]

@Br1 Done, it works as expected.

[domubpkm]

@Br1 I am on RC test OTA-4, it seems ok for me.

[domubpkm]

@Br1

New tests.

I noted this:
. Sometimes a reboot is necessary to get my carrier's DNS fully restored if I no longer want to use cloudflare dns. Just using the 'restore' option in the script is not enough.

. When using cloudflare, in the list of cloudflare DNS servers, some are in the USA (Missouri). Is this normal ? Shouldn't cloudflare DNS all stay in its country of origin like I see with Firefox (all in France for me) ?

Thank you to enlighten me.

[Br1]

@domubpkm said in Change DNS servers, wifi and mobile data:

Sometimes a reboot is necessary to get my carrier's DNS fully restored

It could be caused by dns cache, after restoring try this :

sudo resolvectl flush-caches

if it works, I can add it to next version

@domubpkm said in Change DNS servers, wifi and mobile data:

Shouldn't cloudflare DNS all stay in its country of origin

servers in 120+ countries ... I don’t know what criteria they use

[domubpkm]

@Br1 said in Change DNS servers, wifi and mobile data:

It could be caused by dns cache, after restoring try this :

sudo resolvectl flush-caches

Sorry, i can't confirm it works for me. A reboot is yet necessary.

@Br1 said in Change DNS servers, wifi and mobile data:

Shouldn't cloudflare DNS all stay in its country of origin

servers in 120+ countries ... I don’t know what criteria they use

When i did my precedent feedback, i was in RC TEST OTA-4. Now i am on 'real' OTA-4 and all cloudfare DNS are in my country. So for this, it's solved.

[Br1]

--- New version (only an optimization) here, as reported by @domubpkm to restore the original dns servers reboot is required (added message).