iptables changes

Hello

We have one linux machine in the office which happens to be an important firewall. I just know the basics and need to make one change

Essentially it is forward mysql traffic to another internal machine.

This is the original rule (forward to 192.20.0.17) which is working

$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 3306 -j allowed
$IPTABLES -t nat -A PREROUTING -p TCP -i $INET_IFACE -d $STATIC_IP --dport 3306 -j DNAT --to-destination 192.20.0.17
$IPTABLES -A FORWARD -p tcp -i $INET_IFACE -o $LAN_IFACE -d 192.20.0.17 --dport 3306 -j allowed

and i just need to send it to 192.20.0.15 so i just change -->

$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 3306 -j allowed
$IPTABLES -t nat -A PREROUTING -p TCP -i $INET_IFACE -d $STATIC_IP --dport 3306 -j DNAT --to-destination 192.20.0.15
$IPTABLES -A FORWARD -p tcp -i $INET_IFACE -o $LAN_IFACE -d 192.20.0.15 --dport 3306 -j allowed

and restart the machine.

But this does not work. is there anything else that must be done ?

The 192.20.0.15 mysql is working as i can get telnet response from it.

Any assistance will be appreciated