Linux servers can not access the browser after starting tomcat

For various reasons have tried
before have access to the recently launched can not access, it may be restarted after the recent failure, the cause may not be accessible due to the firewall cause, the solution is to open the firewall ok.
For example port 80 provided to
enter this in cmd on ok

iptables -I INPUT -p tcp --dport 80 -j ACCEPT