echo > /var/ipfire/red/resolv.conf #clear it
[ "$DNS1" != "" ] && echo "nameserver $DNS1" > /var/ipfire/red/resolv.conf
[ "$DNS2" != "" ] && echo "nameserver $DNS2" >> /var/ipfire/red/resolv.conf
echo > /var/ipfire/red/resolv.conf #clear it
[ "$DNS1" != "" ] && echo "nameserver $DNS1" > /var/ipfire/red/resolv.conf
[ "$DNS2" != "" ] && echo "nameserver $DNS2" >> /var/ipfire/red/resolv.conf