Setup CSF Firewall

wget http://www.configserver.com/free/csf.tgz
tar zxvf csf.tgz
cd csf
sudo ./install.sh
sudo service csf start

To tweak the ports edit this file as needed: /etc/csf/csf.conf

Need to make sure Tomcat is listening on a TCP4 port number:

http://askubuntu.com/questions/567093/tomcat7-is-listening-port-but-not-processes-requests

setenv.sh should contain: -Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Addresses=true

netstat -na | grep -e 8080

Should show (not tcp6):

tcp 0 0 0.0.0.0:8080 0.0.0.0:* LISTEN