VPN client over-riding DNS on macOS

fixDNS.sh

#!/usr/bin/env bash

# Create fixDNS password in Keychain Access for login item
PASS=$( security find-generic-password -l "fixDNS" -a fixDNS -w | tr -d '\n' )

# Execute a command with sudo to get a password prompt, next command will be executed with sudo
echo "$PASS" | sudo -S true

# Execute the command with sudo withing the sudo session
echo "$PASS" | sudo -S scutil << EOF
get State:/Network/Service/gpd.pan/DNS
d.remove SearchDomains
d.remove ServerAddress
d.add ServerAddresses * 192.168.1.100 fe80::192:168:1:100
set State:/Network/Service/gpd.pan/DNS
exit
EOF

# Show the DNS entries
scutil --dns | grep 'nameserver\[[0-9]*\]'