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OPS235 Lab 7 - CentOS7

18 bytes added, 08:16, 5 May 2015
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# Confirm that httpd is listening to TCP/80 using the '''netstat''' command.
# Create a small html document called '''/var/www/html/index.html''' that displays a short message.*
# On the centos1 (the http server) confirm everything is working locally by using a browser to connect to '''http://localhost'''
# Set the default firewall configuration on centos1 to REJECT incoming requests to http (TCP/80)
# Confirm that you can't connect by using firefox on centos to connect to centos1 '''http://centos1/'''
# On '''centos2''' confirm that the httpd service is stopped so it cannot interfere with your observations.
# The next step is to establish a <u>tunnel</u>. When you establish a tunnel you make an ssh connection to a remote host and open a new port on the local host. That local host port is then connected to a port on the remote host through the established tunnel. When you send requests to the local port it is forwarded through the tunnel to the remote port.
# Establish a tunnel using a local port on centos2 of 20808, that connects to the remote port on '''centos1''' of 80, using the following command on '''centos2''':<br /><b><code><span style="color:#3366CC;font-size:1.2em;">ssh -L 20808:centos1:80 user@centos1</span></code></b><br><br> '''Note:'''<br>The '''-L''' option (which means Local port) takes one argument:<br><span style="courier">&lt;local-port&gt;:&lt;connect-to-host&gt;:&lt;connect-to-port&gt;</span><br><br> The command basically connects your local port of 20808 to the remote port of 80 on '''centos1'''.<br>This means all requests to 20808 on the <u>localhost</u> ('''centos2''') are actually tunnelled through your ssh connection<br>to port 22 on '''centos1''' and then delivered to port 80 on '''centos1''', bypassing the firewall.<br><br>
# Once the tunnel is established use '''netstat''' to verify the port 20808 is listening on '''centos2'''
# Now using the browser on '''centos2''' connect to '''http://localhost:20808'''
#You should see the index.html page on centos1.
# Close the ssh connection and verify that the port 20808 is no longer listening.
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