→Adding a rule
* Enable and start that service.
* Install links (a command-line web browser) and see if you can connect to http://localhost (it should work by default).
* Try to use Firefox on c7host to see the same webpage from lin1 (
it should not work by default ).
* Check your iptables rules and try to figure out why Firefox cannot connect to lin1 from c7host. Read the output of <code>iptables -L</code> on lin1 carefully looking for clues that iptables on lin1 is letting inbound http traffic (TCP port 80) pass through.
* If the output of <code>iptables -L</code> on lin1 isn't letting HTTP traffic through, which by default configuration it wont, add a rule on lin1 to allow inbound traffic to Apache (TCP port 80).
If you make such a mess that you don't know what you did any longer, there are a couple of things that can help you get back to normal: