Mac OSX Terminal – Change/Set DNS

ByDavid Kittell
| | | |

This may need to change depending on your network interface

Manual Process

# Only friendly names
networksetup -listallnetworkservices

# Useful information
networksetup -listallhardwareports

Running the above will display something like this

An asterisk (*) denotes that a network service is disabled.
Ethernet
FireWire
Wi-Fi
Bluetooth PAN
Thunderbolt Bridge

# Optional but a good start, clear the custom or DHCP DNS
sudo networksetup -setdnsservers Wi-Fi empty

# Statically assign Google DNS
sudo networksetup -setdnsservers Wi-Fi 8.8.8.8 8.8.4.4

# Clear DNS Cache
sudo killall -HUP mDNSResponder

scutil --dns | grep 'nameserver\[[0-9]*\]'

More Automatic Process

Prerequisite 1: Optional but useful, this script originally developed by VMWare has been modified to get some basic
identification for linux based computers. More details at Bash – Unix Identification

curl -O https://gitlab.com/Kittell-Projects/Unix/unixidentification/raw/master/UnixIdentification.sh

Prerequisite 2: The script has some different options

curl -O
https://gist.githubusercontent.com/dkittell/34fe7b7422323fba546948b7448933a5/raw/69924ace7c922aab2e18487514f58baee7ea3554/SetDNS.sh

Basic parameters of the script

  • No parameters passed, you will get information like below 
    		sh SetDNS.sh
		
    		KMacMini
		--------------
		Computer OS: Mac OS X - High Sierra 10.13.6
		Computer Name: KMacMini
		Current User Name: dkittell
		Serial Number: <Serial Number of Mac>
			Remote IP v4 Address: <Public IP>

				Active Network Port(s):
				Interface: Ethernet (en0)
				MAC Address: 3c:07:54:0b:f3:9e (Apple Inc.)

				IP Address v6: fe80::875:3f99:1e31:d84a
				IP Address v4: 10.40.20.4
				Subnet Mask: 255.255.255.0
				Router: 10.40.20.1
				IP CIDR: 10.40.20.4 /24

				Network Speed: 1.00 Gbps
				Link quality: 100 (good)
				DNS Server: Set With DHCP
				--------------
				Network Name: <Wi-Fi Name>
					Interface: Wi-Fi (en1)
					MAC Address: 20:c9:d0:8d:6a:1b (Apple Inc.)

					IP Address v6: fe80::a9:e7bf:6761:11e3
					IP Address v4: 10.40.20.222
					Subnet Mask: 255.255.255.0
					Router: 10.40.20.1
					IP CIDR: 10.40.20.222 /24

					Network Speed: 5.74 Mbps
					Link quality: 100 (good)
					DNS Server: Set With DHCP
					--------------
  • Set DNS parameter, note if you select something other than DHCP the IPv4 IP(s) will be checked to make sure they are valid

    • To set DHCP run the command below and it will set the DNS to DHCP (automatic) 
      				sh SetDNS.sh dhcp
    • To set CleanBrowsing my chosen home DNS 
      				sudo sh SetDNS.sh home
				# or
				sudo sh SetDNS.sh cleanbrowsing
    • To set OpenDNS 
      				sudo sh SetDNS.sh opendns
    • To set Google DNS 
      				sudo sh SetDNS.sh google
				
    		$ sudo sh SetDNS.sh google
		KMacMini
		--------------
				 Computer OS:  Mac OS X - High Sierra 10.13.6
			   Computer Name:  KMacMini
		   Current User Name:  root
			   Serial Number:  <Serial Number of Mac>
		Remote IP v4 Address:  <Public IP>
		
		Active Network Port(s):
				   Interface:  Ethernet (en0)
				 MAC Address:  3c:07:54:0b:f3:9e (Apple Inc.)
		
			   IP Address v6:  fe80::875:3f99:1e31:d84a
			   IP Address v4:  10.40.20.4
				 Subnet Mask:  255.255.255.0
					  Router:  10.40.20.1
					 IP CIDR:  10.40.20.4 /24
		
			   Network Speed:  1.00 Gbps
				Link quality:  100 (good)
				  DNS Server:  Set With DHCP
		
		Validating 8.8.8.8 is accessible...
		1
		Validating 8.8.4.4 is accessible...
		1
		
				  DNS Updated
				  DNS Server:  8.8.8.8 8.8.4.4
		
		Validating 8.8.8.8 is accessible...
		1
		Validating 8.8.4.4 is accessible...
		1
		
				  DNS Updated
				  DNS Server:  8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844
		--------------
				Network Name:  <Wi-Fi Name>
				   Interface:  Wi-Fi (en1)
				 MAC Address:  20:c9:d0:8d:6a:1b (Apple Inc.)
		
			   IP Address v6:  fe80::a9:e7bf:6761:11e3
			   IP Address v4:  10.40.20.222
				 Subnet Mask:  255.255.255.0
					  Router:  10.40.20.1
					 IP CIDR:  10.40.20.222 /24
		
			   Network Speed:  5.74 Mbps
				Link quality:  100 (good)
				  DNS Server:  Set With DHCP
				
		Validating 8.8.8.8 is accessible...
		1
		Validating 8.8.4.4 is accessible...
		1
		
				  DNS Updated
				  DNS Server:  8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844
		--------------

Automatic Process Script

#!/bin/sh

# SetDNS.sh
#
# Created by David Kittell on 6/14/19.
#

# For updates download
# curl -O
https://gist.githubusercontent.com/dkittell/34fe7b7422323fba546948b7448933a5/raw/69924ace7c922aab2e18487514f58baee7ea3554/SetDNS.sh

# Variables - Start
sExternalIPService="http://dns.kittell.net/ip.php"
sExternalMACALService="http://dns.kittell.net/macaltext.php?address="

# Get remote/public IP address
remoteip=$(curl -sSf -m 5 --connect-timeout 5 $sExternalIPService)

# Get computer name
computername=$(scutil --get ComputerName)

# Get serial number
sSerialNumber=$(system_profiler SPHardwareDataType |grep "Serial Number (system)" |awk '{print $4}' | cut -d/ -f1)
#echo $sSerialNumber
# Variables - Stop

# Run Once - Start
#curl -O https://gitlab.com/Kittell-Projects/Unix/unixidentification/raw/master/UnixIdentification.sh
# Run Once - Stop

# Functions - Start
# Function to convert IP Subnet Mask to CIDR
mask2cdr ()
{
# Assumes there's no "255." after a non-255 byte in the mask
local x=${1##*255.}
set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*}
    x=${1%%$3*}
    echo $(( $2 + (${#x}/4) ))
}

IPUpStatus()
{
    if ping -c 1 $1 &> /dev/null
    #if ping -c 1 8.8.8.8 &> /dev/null
    #if ping -c 1 2a0d:2a00:1:abab:23b9:93ef:2da9:dd2f &> /dev/null
    then
        rc=1
    else
        rc=0
    fi
    
    #rc=$(ping -c 1 -m 5 "$1" | grep "100.0% packet loss")
    echo $rc
}

DHCPDNS()
{
    #sudo clear
    sudo networksetup -setwebproxystate "$ActiveNetworkName" Off
    sudo networksetup -setsecurewebproxystate "$ActiveNetworkName" Off
    sudo networksetup -setv6automatic "$ActiveNetworkName"
    sudo networksetup -setdnsservers "$ActiveNetworkName" empty
    
    sudo networksetup -setdhcp "$ActiveNetworkName"
    sudo networksetup -setsearchdomains "$ActiveNetworkName" empty
    sudo networksetup -setproxybypassdomains "$ActiveNetworkName" empty
    sudo dscacheutil -flushcache
    sudo killall -HUP mDNSResponder
    say "DNS Updated for $ActiveNetworkName"
    
    echo "\n          DNS Updated"
    
    DHCPActive=$(networksetup -getinfo "$ActiveNetworkName" | grep DHCP)
    # echo $DHCPActive
    dnsserver=$(networksetup -getdnsservers "$ActiveNetworkName" )
    # echo $dnsserver
    
    if [[ -z $dnsserver || $DHCPActive == "DHCP Configuration" ]]; then
        if [[ $DHCPActive ]]; then
            echo "          DNS Server:  Set With DHCP"
        else
            echo "          DNS Server:  Unknown"
        fi
    else
        echo "         DNS Server:  $dnsserver"
    fi
}

StaticDNS()
{
    if [[ ! -z "$1" ]]; then
        echo "\nValidating $1 is accessible..."
        IPUpStatus "$1"
        if [[ $rc == 1 ]] ; then
            sudo networksetup -setv6automatic "$ActiveNetworkName"
            sudo networksetup -setdhcp "$ActiveNetworkName" empty # Disable DHCP if it's on
            sudo networksetup -setwebproxystate "$ActiveNetworkName" Off
            sudo networksetup -setsecurewebproxystate "$ActiveNetworkName" Off
            sudo networksetup -setdnsservers "$ActiveNetworkName" empty
            sudo networksetup -setsearchdomains "$ActiveNetworkName" empty
            sudo networksetup -setproxybypassdomains "$ActiveNetworkName" empty
            if [[ ! -z "$2" ]]; then
                echo "Validating $2 is accessible..."
                IPUpStatus "$1"
                if [[ $rc == 1 ]] ; then
                    sudo networksetup -setdnsservers "$ActiveNetworkName" $1 $2 $3 $4
                else
                    sudo networksetup -setdnsservers "$ActiveNetworkName" $1
                fi
            else
                sudo networksetup -setdnsservers "$ActiveNetworkName" $1
            fi
            
            sudo dscacheutil -flushcache
            sudo killall -HUP mDNSResponder
            say "DNS Updated for $ActiveNetworkName"
            
            echo "\n          DNS Updated"
            
            DHCPActive=$(networksetup -getinfo "$ActiveNetworkName" | grep DHCP)
            dnsserver=$(networksetup -getdnsservers "$ActiveNetworkName" | cut -d/ -f1|tr '\n' ' ')
            
            if [[ -z $dnsserver  ]]; then
                if [[ $DHCPActive ]]; then
                    echo "          DNS Server:  Set With DHCP"
                else
                    echo "         DNS Server:  Unknown"
                fi
            else
                echo "          DNS Server:  $dnsserver"
            fi
            
        else
            echo "Supplied DNS is not valid, setting DHCP"
            DHCPDNS
        fi
    fi
}

NetworkInfo ()
{
    # List all Network ports
    NetworkPorts=$(ifconfig -uv | grep '^[a-z0-9]' | awk -F : '{print $1}')
    
    echo "$computername"
    echo "--------------"
    echo "         Computer OS:  $(sh UnixIdentification.sh)"
    echo "       Computer Name:  $computername"
    echo "   Current User Name:  $(whoami)"
    echo "       Serial Number:  $sSerialNumber"
    
    if [[ $remoteip ]]; then
        echo "Remote IP v4 Address:  $remoteip\n"
    else
        echo "Remote IP v4 Address:  Unable To Determine\n"
    fi
    
    echo "Active Network Port(s):"
    
    for val in $(echo $NetworkPorts); do   # Get for all available hardware ports their status
        activated=$(ifconfig -uv "$(echo $val)" | grep 'status: ' | awk '{print $2}')
        
        # Get VPN Information - Start
        if [[ ":${NetworkPorts[*]}:" =~ "ppp0" ]]; then
            VPNActivated=$(ifconfig -uv "ppp0" | grep 'state availability' | grep 'true')
            if [ ! -z "VPNActivated" ]; then
                #echo "VPN Active"
                VPNipaddress=$(ifconfig -uv "ppp0" | grep 'inet' | cut -d ' ' -f2)
                #        VPNipaddressTranslation=$(ifconfig -uv "ppp0" | grep 'inet' | cut -d ' ' -f4)
                #echo $VPNipaddress
            fi
        fi
        
        if [[ ":${NetworkPorts[*]}:" =~ "gpd0" ]]; then
            VPNActivated=$(ifconfig -uv "gpd0" | grep 'state availability' | grep 'true')
            if [ ! -z "VPNActivated" ]; then
                #echo "VPN Active"
                VPNipaddress=$(ifconfig -uv "gpd0" | grep 'inet' | cut -d ' ' -f2 | sed 's/^[ \t]*//;s/[ \t]*$//')
                #echo $VPNipaddress
            fi
        fi
        # Get VPN Information - Stop
        
        if [ "$activated" == "active" ]; then
            label=$(ifconfig -uv "$(echo $val)" | grep 'type' | awk '{print $2}')
            # echo $label
            # ActiveNetwork=$(route get default | grep interface | awk '{print $2}')
            # ActiveNetworkName=$(networksetup -listallhardwareports | grep -B 1 "$label" | awk '/Hardware Port/{ print }'|cut -d " " -f3- | uniq)
            # ActiveNetworkName=$(networksetup -listnetworkserviceorder | grep $ActiveNetwork -B1  | head -1 | cut -d ")" -f2 | sed "s/^[ \t]*//")
            ActiveNetworkName=$(networksetup -listnetworkserviceorder | grep "$val" -B1 | grep -v "$val" | cut -d ')' -f2 | sed 's/^[ ]*//;s/[ ]*$//')
            
            #echo $ActiveNetwork
            #echo $ActiveNetworkName
            state=$(ifconfig -uv "$val" | grep 'status: ' | awk '{print $2}')
            #echo $state
            ipaddress=$(ifconfig -uv "$val" | grep 'inet ' | awk '{print $2}' | cut -d/ -f1|tr '\n' ' ')
            # echo $ipaddress
            ipaddressv6=$(ifconfig "$val" | grep inet6 | grep 'scopeid' | cut -d ' ' -f2 | cut -d '%' -f1 | cut -d/ -f1|tr '\n' ' ')
            netmask=$(ipconfig getpacket "$val" | grep 'subnet_mask (ip):' | awk '{print $3}' | tr -d '[:space:]')
            #echo $netmask
            
            if [[ -z $(ifconfig -uv "$val" | grep 'link rate: ' | awk '{print $3, $4}' | sed 'N;s/\n/ up /' ) ]]; then
                networkspeed="$(ifconfig -uv "$val" | grep 'link rate: ' | cut -d ':' -f2 | sed 's/^[ \t]*//;s/[ \t]*$//')"
            else
                networkspeed="$(ifconfig -uv "$val" | grep 'link rate: ' | awk '{print $3, $4}' | sed 'N;s/\n/ up /' ) down"
            fi
            
            quality=$(ifconfig -uv "$val" | grep 'link quality:' | awk '{print $3, $4}')
            #echo $quality
            
            macaddress=$(ifconfig -uv "$val" | grep 'ether ' | awk '{print $2}')
            #echo $macaddress
            macal=$(curl -s "$sExternalMACALService$macaddress" | sed 's/^[ ]*//;s/[ ]*$//')
            #echo $macal
            
            router=$(ipconfig getpacket "$val" | grep 'router (ip_mult):' | sed 's/.*router (ip_mult): {\([^}]*\)}.*/\1/')
            #echo $router
            DHCPActive=$(networksetup -getinfo "$ActiveNetworkName" | grep DHCP)
            #echo $DHCPActive
            #dnsserver=$(networksetup -getdnsservers "$ActiveNetworkName" | awk '{print $1, $2}' | sed 'N;s/\n//' )
            dnsserver=$(networksetup -getdnsservers "$ActiveNetworkName" | cut -d/ -f1|tr '\n' ' ')
            #echo $dnsserver
            
            if [[ ! -z "$netmask" ]]; then
                
                if [[ $ipaddress ]]; then
                    
                    # Is this a WiFi associated port? If so, then we want the network name
                    if [ "$label" = "Wi-Fi" ]; then
                        WiFiName=$(/System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport -I | grep '\sSSID:' | sed 's/.*: //')
                        #echo $WiFiName
                        echo "        Network Name:  $WiFiName"
                    fi
                    
                    echo "           Interface:  $ActiveNetworkName ($val)"
                    echo "         MAC Address:  $macaddress ($macal)\n"
                    
                    if [[ ! -z "$ipaddressv6" ]]; then
                        echo "       IP Address v6:  $ipaddressv6"
                    fi
                    
                    echo "       IP Address v4:  $ipaddress"
                    echo "         Subnet Mask:  $netmask"
                    echo "              Router:  $router"
                    echo "             IP CIDR:  $ipaddress/$(mask2cdr $netmask)\n"
                    echo "       Network Speed:  $networkspeed"
                    echo "        Link quality:  $quality"
                    
                    
                    if [ ! -z "$VPNipaddress" ]; then
                        echo "      VPN IP Address:  $VPNipaddress\n"
                    fi
                    
                    
                    if [[ -z $dnsserver || $DHCPActive == "DHCP Configuration" ]]; then
                        if [[ $DHCPActive ]]; then
                            echo "          DNS Server:  Set With DHCP"
                        else
                            echo "          DNS Server:  Unknown"
                        fi
                    else
                        echo "          DNS Server:  $dnsserver"
                    fi
                    
                    case "$1" in
                        "dhcp")
                            DHCPDNS
                        ;;
                        "home")
                            # StaticDNS 10.40.20.3
                            # StaticDNS 185.228.168.80 185.228.169.80 # IPv4 CleanBrowsing
                            StaticDNS 185.228.168.80 185.228.169.80 2a0d:2a00:1:abab:23b9:93ef:2da9:dd2f 2a0d:2a00:2:abab:23b9:93ef:2da9:dd2f # IPv6 CleanBrowsing
                        ;;
                        "cleanbrowsing")
                            # StaticDNS 185.228.168.80 185.228.169.80 # IPv4 CleanBrowsing
                            StaticDNS 185.228.168.80 185.228.169.80 2a0d:2a00:1:abab:23b9:93ef:2da9:dd2f 2a0d:2a00:2:abab:23b9:93ef:2da9:dd2f # IPv6 CleanBrowsing
                        ;;
                        "opendns")
                            # StaticDNS 208.67.222.222 208.67.220.220 # IPv4 OpenDNS
                            StaticDNS 208.67.222.222 208.67.220.220 2620:119:35::35 2620:119:53::53 # IPv6 OpenDNS
                        ;;
                        "google")
                            # StaticDNS 8.8.8.8 8.8.4.4 # IPv4 OpenDNS
                            StaticDNS 8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844 # IPv6 OpenDNS
                        ;;
                        *)
                            sConfig="0"
                        ;;
                    esac
                    echo "--------------"
                    
                fi
            fi
        fi
    done
}
# Functions - Stop

# Check Online Status - Start
#nc -z 8.8.8.8 53  >/dev/null 2>&1
#online=$?
#if [ $online -eq 0 ]; then
#  echo "Online, continuing...\n"
#
NetworkInfo $(echo $1 | awk '{print tolower($0)}')
#
#  remoteip=$(dig +short myip.opendns.com @resolver1.opendns.com)
#  echo "Remote IP: $remoteip"
#
#else
#  echo "Sorry you are offline, please connect and try again."
#  exit
#fi
# Check Online Status - Stop
Originally Posted on May 27, 2016
Last Updated on June 4, 2020
All information on this site is shared with the intention to help. Before any source code or program is ran on a production (non-development) system it is suggested you test it and fully understand what it is doing not just what it appears it is doing. I accept no responsibility for any damage you may do with this code.