Force Tomcat to use IPv4 on server with both IPV6 and IPV4 configured
On RHEL7, Tomcat7 may start up and listen to just ipv6 interfaces by default. This typically results in browser connection errors. You can force Tomcat to startup and listen to ipv4 interfaces.
In $CATALINA_HOME/bin/setenv.sh (installer included) or /etc/tomcat/tomcat.conf (tomcat rpm)
JAVA_OPTS="$JAVA_OPTS -Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Addresses=true"