====== Remote control ======
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[[dpi:dpi_components:platform:subscriber_management:subsman_remote:start#remote_execution_of_ssh_commands|The remote execution of SSH commands]] is the recommended method to control DPI from another computer. Billing systems typically have the built in support of this control method.

The alternative remote control methods are: [[dpi:dpi_components:platform:subscriber_management:subsman_remote:start#remote_execution_of_fdpi_ctrl_utility|remote execution of fdpi_ctrl utility]] and installation of an additional remote control SW on DPI server, like telnet server and similar. You can use the snmp agent to remotely monitor the operation of CentOS and [[veos:installation|VEOS]].

===== Remote execution of SSH commands =====

We advise to authenticate users by public keys to execute command on DPI server remotely by SSH with no need to enter password.

To use this method: on the control server:
  - We create a pair of public and private keys:<code>ssh-keygen -t rsa</code>Default values should be selected in the dialogue. Passphrase should be left empty for convenience((Alternatively, one can use the functionality of ssh-agent to store passwords))
  - We copy the public key to DPI server:<code>ssh-copy-id dpi_user@dpi_host 
or manually:
cat ~/.ssh/id_rsa.pub | ssh dpi_user@dpi_host "mkdir -p ~/.ssh && cat >>  ~/.ssh/authorized_keys"</code>

Then we check and fix the rights on file authorized_keys on DPI server:<code>chmod 700 ~dpi_user/.ssh/
chmod 600 ~dpi_user/.ssh/authorized_keys
restorecon -Rv ~dpi_user/.ssh/</code>

Next, we check the operation of the remote execution of fdpi_ctrl from the control server:
<code>
ssh dpi_user@dpi_host "fdpi_ctrl load --service 6 --login test"
</code>
In case this instruction does not work, try to find some hints in the log file /var/log/secure on DPI server. One can also switch the diagnostic mode on SSH: ssh -v …

===== Remote execution of fdpi_ctrl utility =====

To execute fdpi_ctrl utility remotely one has to make the following actions:
  - To enable listening for the network control interface in DPI configuration file /etc/dpi/fastdpi.conf:<code>ctrl_dev=eth0</code> 
  - To open the access to the port configured by ctrl_port in firewall settings /etc/sysconfig/iptables and to limit an access to DPI host from the control server only: <code>-A INPUT -m state --state NEW -m tcp -s 192.168.0.2 -p tcp --dport 2900 -j ACCEPT</code>
  - To copy fdpi_ctrl utility to the control server and start it with an argument -r host:port:<code>fdpi_ctrl load --service 6 --login test -r 192.168.0.1:2900</code>

:!: Please take care to update fdpi_ctrl on the control server on each DPI update.