pfSense

#!/bin/sh

# Set the router for this interface

echo $1 > /tmp/$2_router

# Remove file if it exists

if [ -f /var/etc/nameserver_$2 ]; then 

	rm -f /var/etc/nameserver_$2

fi

# DNS1

if [ "$3" != "DNS0" ]; then 

	echo $3 >> /var/etc/nameserver_$2

fi

# DNS2

if [ "$4" != "DNS1" ]; then 

	echo $4 >> /var/etc/nameserver_$2

fi