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OPS235 Lab 7

58 bytes added, 07:45, 28 June 2016
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# You should see a number of packages installed including <b>openssh-clients</b> and <b>openssh-server</b>
# <b><code><span style="color:#3366CC;font-size:1.2em;">openssh-server</span></code></b> installs a service called '''sshd'''. Confirm that this service is running by issuing the command:<br /><b><code><span style="color:#3366CC;font-size:1.2em;">systemctl status sshd</span></code></b><br><br>'''NOTE:''' We can use the '''netstat''' utility as a trouble-shooting / confirmation tool to view the SSH service and determine which STATE the SSH service is performing:
::*'''LISTENING''' (waiting for a ssh connection attempt)::*'''ESTABLISHED''' (connection established)::*'''CLOSED''' (connection is closed)::*'''WAITING''' (time between connection closed, and changing to LISTENING mode)<br><br># <ol><li value="6">Now that you know the service is running, investigate what '''port number''' and '''protocol''' sshd uses by issuing the command:<br /><b><code><span style="color:#3366CC;font-size:1.2em;">netstat -atunp | grep sshd</span></code></b></li># <li>What protocol and port is the sshd process using? What is the state of the port? Why would you think that UDP ports don't have a state?</li># <li>Reissue the <b><code><span style="color:#3366CC;font-size:1.2em;">netstat</span></code></b> command without the '''-n''' option. What is the difference?</li># <li>Make sure the '''sshd''' service is running on '''all 3 of your VM's'''</li># <li>Remember that you can view the '''/etc/services''' file in case you need to reference a service with a corresponding port number.</li></ol>
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