I entered the following commands into a Debian Linux terminal:
sysctl net.ipv4.ip_forward=1 iptables -t nat -A PREROUTING -p tcp --dport Port2 -j DNAT --to-destination yyy.yyy.yyy.yyy:Port1 iptables -t nat -A POSTROUTING -j MASQUERADE
Soon after, mySQL failed and it would not allow anything to connect to it. One of the errors was
"Host xxx-xxx-xxx-xxx.static.xyzxyzxyz.xyz' is not allowed to connect to this MYSQL server"
The xxx-xxx-xxx-xxx is the IP in which I entered the Iptables commands above.