How to make vpnclient connect to vpnserver

I introduced how to setup VPN by these articles.

How to obtain static IP address by LightSail and softether for 3.5 USD per month?

I am running Nextcloud on my Raspberry Pi.I buy static IP address from internet service provider(=ISP) for 10 USD per mo...

linuxfun.org

2022.08.27

Activated certificate based authentication on Softether

In below post I established VPN by Softether. In this post I switched to use certicate based authentication which are su...

linuxfun.org

2022.08.29

In this article I will introduce how to make vpnclient connect to vpnserver when start up.

How to do

I implemented this shell script (bash) /opt/vpnclient/vpnclient.sh.

#!/bin/bash

status(){
        echo "==========status======="
}

start() {
        echo "==========start==========="
        /opt/vpnclient/vpnclient start
        echo -e $'\n' | /opt/vpnclient/vpncmd /CLIENT /CMD AccountConnect virtual_connection
        ip address add 192.168.100.150/24 dev vpn_virtual_nic
}

stop() {
        echo "===========stop============"
        echo -e $'\n' | /opt/vpnclient/vpncmd /CLIENT /CMD AccountDisconnect virtual_connection
        /opt/vpnclient/vpnclient stop
}

restart() {
        stop;
        echo "sleeping.........";
        sleep 3;
        start;
}
case "$1" in
        'start')
                start
                ;;
        'stop')
                stop
                ;;
        'status')
                status
                ;;
        'restart')
                restart
                ;;
        *)
                echo "usage: $0 {start|stop|restart|status}"
                exit 1
                ;;
esac

Normally vpnclient needs user input, but vpnclient has command line options to avoid user inputs and can be automated.

This is official site.
If you are interested in please have a look.
– 6.2.3 is which I would like you to see.

6.2 General Usage of vpncmd - SoftEther VPN Project

www.softether.org

Furthermore I passed “Enter” key code by echo -e $’\n’ to skip user inputs for selecting which vpnclient to be connected (see below).

sudo /opt/vpnclient/vpncmd
vpncmd command - SoftEther VPN Command Line Management Utility
SoftEther VPN Command Line Management Utility (vpncmd command)
Version 4.39 Build 9772   (English)
Compiled 2022/04/26 18:00:50 by buildsan at crosswin
Copyright (c) SoftEther VPN Project. All Rights Reserved.

By using vpncmd program, the following can be achieved. 

1. Management of VPN Server or VPN Bridge 
2. Management of VPN Client
3. Use of VPN Tools (certificate creation and Network Traffic Speed Test Tool)

Select 1, 2 or 3: 2

Specify the host name or IP address of the computer that the destination VPN Client is operating on. 
If nothing is input and Enter is pressed, connection will be made to localhost (this computer).
Hostname of IP Address of Destination: 

I updated /etc/systemd/system/vpnclient.service to call this vpnclient.sh like below.

[Unit]
Description=SoftEther VPN Client
After=network.target

[Service]
ExecStart=/opt/vpnclient/vpnclient.sh start
ExecStop=/opt/vpnclient/vpnclient.sh stop
Type=forking
Restart=always

[Install]
WantedBy=graphical.target

That’s it.

If everything is successful, then vpnclient will automatically connect to vpnserver after boot up.

Conclusion

How was it?

This is small but very useful! isn’t it?