This tutorial is going to show you how to run your own VPN server by installing OpenConnect VPN server on Ubuntu 20.04. OpenConnect VPN server, aka ocserv, is an open-source implementation of Cisco AnyConnnect VPN protocol, which is widely used in businesses and universities. AnyConnect is an SSL-based VPN protocol that allows individual users to connect to a remote network.
Why Set Up Your Own VPN Server?
- Maybe you are a VPN service provider or a system administrator, which behooves you to set up our own VPN server.
- You don’t trust the no-logging policy of VPN service providers, so you go the self-host route.
- You can use VPN to implement network security policy. For example, if you run your own email server, you can require users to log in only from the IP address of the VPN server by creating an IP address whitelist in the firewall. Thus, your email server is hardened to prevent hacking activities.
- Perhaps you are just curious to know how VPN server works.

Features of OpenConnect VPN Server
- Lightweight and fast. In my test, I can watch YouTube 4K videos with OpenConnect VPN. YouTube is blocked in my country (China).
- Runs on Linux and most BSD servers.
- Compatible with Cisco AnyConnect client
- There are OpenConnect client software for Linux, MacOS, Windows and OpenWRT. For Android and iOS, you can use the Cisco AnyConnect Client.
- Supports password authentication and certificate authentication
- Supports RADIUS accounting.
- Easy to set up
I particularly like the fact that compared to other VPN technologies, it is very easy and convenient for the end-user to use OpenConnect VPN. Whenever I install a Linux distro on my computer and want to quickly unblock websites or hide my IP address, I install OpenConnect client and connect to the server with just two lines of commands:
sudo apt install openconnect
sudo openconnect -b vpn.mydomain.com
There is also OpenConnect VPN client for Fedora, RHEL, CentOS, Arch Linux and OpenSUSE. You can easily install it with your package manager.
sudo dnf install openconnect
sudo yum install openconnect
sudo pacman -S openconnect
Prerequisites
To follow this tutorial, you will need a VPS (Virtual Private Server) that can access blocked websites freely (Outside of your country or Internet filtering system). I recommend Vultr VPS (This is my referral link. You can get $50 free credit by creating an account at Vultr via my referral link). They offer 512M memory high-performance KVM VPS for just $2.5 per month, which is perfect for your private VPN server. Once you have a VPS, install Ubuntu 20.04 on it and follow the instructions below.
You also need a domain name. I registered my domain name from NameCheap because the price is low and they give whois privacy protection free for life.
Update: The new Vultr $2.5/month plan includes IPv6 address only. You can select the $3.5/month plan at the New York (NJ) data center to have both IPv4 and IPv6 addresses.
Step 1: Install OpenConnect VPN Server on Ubuntu 20.04
Log into your Ubuntu 20.04 server. Then use apt to install the ocserv package from the default Ubuntu repository.
sudo apt update
sudo apt install ocserv
Once installed, the OpenConnect VPN server is automatically started. You can check its status with:
systemctl status ocserv
Sample output:
● ocserv.service – OpenConnect SSL VPN server
Loaded: loaded (/lib/systemd/system/ocserv.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2020-04-12 19:57:08 HKT; 12s ago
Docs: man:ocserv(8)
Main PID: 216409 (ocserv-main)
Tasks: 2 (limit: 9451)
Memory: 1.6M
CGroup: /system.slice/ocserv.service
├─216409 ocserv-main
└─216429 ocserv-sm
Hint: If the above command doesn’t quit immediately, you can press the Q key to gain back control of the terminal.
If it’s not running, then you can start it with:
sudo systemctl start ocserv
By default OpenConnect VPN server listens on TCP and UDP port 443. If it’s being used by web server, then the VPN server would probably fail to start. We will see how to change the port in OpenConnect VPN configuration file later.
If there’s a firewall running on your server, then you will need to open port 80 and 443. For example, if you use UFW, then run the following command.
sudo ufw allow 80,443/tcp
Step 2: Install Let’s Encrypt Client (Certbot) on Ubuntu 20.04 Server
The gnutls-bin package installed along with ocserv provides tools to create your own CA and server certificate, but we will obtain and install Let’s Encrypt certificate. The advantage of using Let’s Encrypt certificate is that it’s free, easier to set up and trusted by VPN client software.
Run the following commands to install Let’s Encrypt client (certbot) from the default Ubuntu repository.
sudo apt install certbot
To check the version number, run
certbot –version
Sample output:
certbot 0.40.0
Step 3: Obtain a Trusted TLS Certificate from Let’s Encrypt
I recommend using the standalone or webroot plugin to obtain TLS certificate for ocserv.
Standalone Plugin
If there’s no web server running on your Ubuntu 20.04 server and you want OpenConnect VPN server to use port 443, then you can use the standalone plugin to obtain TLS certificate from Let’s Encrypt. Run the following command. Don’t forget to set A record for your domain name.
sudo certbot certonly –standalone –preferred-challenges http –agree-tos –email [email protected] -d vpn.example.com
Where:
- certonly: Obtain a certificate but don’t install it.
- –standalone: Use the standalone plugin to obtain a certificate
- –preferred-challenges http: Perform http-01 challenge to validate our domain, which will use port 80.
- –agree-tos: Agree to Let’s Encrypt terms of service.
- –email: Email address is used for account registration and recovery.
- -d: Specify your domain name.
As you can see the from the following screenshot, I successfully obtained the certificate.

Using webroot Plugin
If your Ubuntu 20.04 server has a web server listening on port 80 and 443, then it’s a good idea to use the webroot plugin to obtain a certificate because the webroot plugin works with pretty much every web server and we don’t need to install the certificate in the web server.
First, you need to create a virtual host for vpn.example.com.
Apache
If you are using Apache, then
sudo nano /etc/apache2/sites-available/vpn.example.com.conf
And paste the following lines into the file.
ServerName vpn.example.com
DocumentRoot /var/www/ocserv
Save and close the file. Then create the web root directory.
sudo mkdir /var/www/ocserv
Set www-data (Apache user) as the owner of the web root.
sudo chown www-data:www-data /var/www/ocserv -R
Enable this virtual host.
sudo a2ensite vpn.example.com
Reload Apache for the changes to take effect.
sudo systemctl reload apache2
Once virtual host is created and enabled, run the following command to obtain Let’s Encrypt certificate using webroot plugin.
sudo certbot certonly –webroot –agree-tos –email [email protected] -d vpn.example.com -w /var/www/ocserv
Nginx
If you are using Nginx, then
sudo nano /etc/nginx/conf.d/vpn.example.com.conf
Paste the following lines into the file.
server {
listen 80;
server_name vpn.example.com;
root /var/www/ocserv/;
location ~ /.well-known/acme-challenge {
allow all;
}
}
Save and close the file. Then create the web root directory.
sudo mkdir -p /var/www/ocserv
Set www-data (Nginx user) as the owner of the web root.
sudo chown www-data:www-data /var/www/ocserv -R
Reload Nginx for the changes to take effect.
sudo systemctl reload nginx
Once virtual host is created and enabled, run the following command to obtain Let’s Encrypt certificate using webroot plugin.
sudo certbot certonly –webroot –agree-tos –email [email protected] -d vpn.example.com -w /var/www/ocserv
Step 4: Edit OpenConnect VPN Server Configuration File
Edit ocserv main configuration file.
sudo nano /etc/ocserv/ocserv.conf
First, we need to configure password authentication. By default, password authentication through PAM (Pluggable Authentication Modules) is enabled, which allows you to use Ubuntu system accounts to login from VPN clients. This behavior can be disabled by commenting out the following line.
auth = “pam[gid-min=1000]”
If we want users to use separate VPN accounts instead of system accounts to login, we need to add the following line to enable password authentication with a password file.
auth = “plain[passwd=/etc/ocserv/ocpasswd]”
After finishing editing this config file, we will see how to use ocpasswd tool to generate the /etc/ocserv/ocpasswd file, which contains a list of usernames and encoded passwords.
Note: Ocserv supports client certificate authentication, but Let’s Encrypt does not issue client certificate. You need to set up your own CA to issue client certificate.
Next, if you don’t want ocserv to use TCP and UDP port 443, then find the following two lines and change the port number. Otherwise leave them alone.
tcp-port = 443
udp-port = 443
Then find the following two lines. We need to change them.
server-cert = /etc/ssl/certs/ssl-cert-snakeoil.pem
server-key = /etc/ssl/private/ssl-cert-snakeoil.key
Replace the default setting with the path of Let’s Encrypt server certificate and server key file.
server-cert = /etc/letsencrypt/live/vpn.example.com/fullchain.pem
server-key = /etc/letsencrypt/live/vpn.example.com/privkey.pem
Then, set the maximal number of clients. Default is 128. Set to zero for unlimited.
max-clients = 128
Set the number of devices a user is able to login from at the same time. Default is 2. Set to zero for unlimited.
max-same-clients = 2
Next, find the following line. Change false to true to enable MTU discovery, which can optimize VPN performance.
try-mtu-discovery = false
You can set the time that a client is allowed to stay idle before being disconnected via the following two parameters. If you prefer the client to stay connected indefinitely, then comment out these two parameters.
idle-timeout=1200
mobile-idle-timeout=1800
After that, set the default domain to vpn.example.com.
default-domain = vpn.example.com
The IPv4 network configuration is as follows by default. This will cause problems because many home routers also set the IPv4 network range to 192.168.1.0/24.
ipv4-network = 192.168.1.0
ipv4-netmask = 255.255.255.0
We can use another private IP address range (10.10.10.0/24) to avoid IP address collision, so change the value of ipv4-network to
ipv4-network = 10.10.10.0
Now uncomment the following line to tunnel all DNS queries via the VPN.
tunnel-all-dns = true
The default DNS resolver addresses are as follows, which is fine.
dns = 8.8.8.8
dns = 1.1.1.1
Note: If you are a VPN service provider, then it’s a good practice to run your own DNS resolver on the same server. If there’s a DNS resolver running on the same server, then specify the DNS as
dns = 10.10.10.1
10.10.10.1 is the IP address of OpenConnect VPN server in the VPN LAN. This will speed up DNS lookups a little bit for clients because the network latency between the VPN server and the DNS resolver is eliminated.
Then comment out all the route parameters (add # symbol at the beginning of the following four lines), which will set the server as the default gateway for the clients.
route = 10.0.0.0/8
route = 172.16.0.0/12
route = 192.168.0.0/16
no-route = 192.168.5.0/255.255.255.0
Save and close the file Then restart the VPN server for the changes to take effect.
sudo systemctl restart ocserv
Step 5: Create VPN Accounts
Now use the ocpasswd tool to generate VPN accounts.
sudo ocpasswd -c /etc/ocserv/ocpasswd username
You will be asked to set a password for the user and the information will be saved to /etc/ocserv/ocpasswd file. To reset password, simply run the above command again.
Step 6: Enable IP Forwarding
In order for the VPN server to route packets between VPN clients and the Internet, we need to enable IP forwarding. Edit sysctl.conf file.
sudo nano /etc/sysctl.conf
Add the following line at the end of this file.
net.ipv4.ip_forward = 1
Save and close the file. Then apply the changes with the below command. The -p option will load sysctl settings from /etc/sysctl.conf file. This command will preserve our changes across system reboots.
sudo sysctl -p
Step 7: Configure IP Masquerading in Firewall
We need to set up IP masquerading in the server firewall, so that the server becomes a virtual router for VPN clients. I will use UFW, which is a front end to the iptables firewall. Install UFW on Ubuntu with:
sudo apt install ufw
First, you need to allow SSH traffic.
sudo ufw allow 22/tcp
Then edit /etc/default/ufw file.
sudo nano /etc/default/ufw
Change the default forward policy from “DROP” to “ACCEPT”.
DEFAULT_FORWARD_POLICY=”ACCEPT”
Save and close the file. Next, find the name of your server’s main network interface.
ip addr
As you can see, it’s named ens3 on my Ubuntu server.

To configure IP masquerading, we have to add iptables command in a UFW configuration file.
sudo nano /etc/ufw/before.rules
By default, there are some rules for the filter table. Add the following lines at the end of this file. Replace ens3 with your own network interface name.
# NAT table rules
*nat
:POSTROUTING ACCEPT [0:0]
-A POSTROUTING -o ens3 -j MASQUERADE
# End each table with the ‘COMMIT’ line or these rules won’t be processed
COMMIT
In Nano text editor, you can go to the end of the file by pressing Ctrl+W, then pressing Ctrl+V.
The above lines will append (-A) a rule to the end of of POSTROUTING chain of nat table. It will link your virtual private network with the Internet. And also hide your network from the outside world. So the Internet can only see your VPN server’s IP, but can’t see your VPN client’s IP, just like your home router hides your private home network.
Save and close the file. Then enable UFW.
sudo ufw enable
If you have enabled UFW before, then you can use systemctl to restart UFW.
sudo systemctl restart ufw
Now if you list the rules in the POSTROUTING chain of the NAT table by using the following command:
sudo iptables -t nat -L POSTROUTING
You can see the Masquerade rule.

Step 8: Open Port 443 in Firewall
Run the following command to open TCP and UDP port 443. If you configured a different port for ocserv, then change 443 to your configured port.
sudo ufw allow 443/tcp
sudo ufw allow 443/udp
Now OpenConnect VPN server is ready to accept client connections.
For those of you who run a local DNS resolver, if you specified 10.10.10.1 as the DNS server for VPN clients, then you must allow VPN clients to connect to port 53 with the following UFW rule.
sudo ufw insert 1 allow in from 10.10.10.0/24
You also need to edit the BIND DNS server’s configuration to allow VPN clients to send recursive DNS queries like below.
allow-recursion { 127.0.0.1; 10.10.10.0/24; };
How to Install and Use OpenConnect VPN client on Ubuntu 20.04 Desktop
Run the following command to install OpenConnect VPN command line client on Ubuntu desktop.
sudo apt install openconnect
You can Connect to VPN from the command line like below. -b flag will make it run in the background after connection is established.
sudo openconnect -b vpn.example.com:port-number
You will be asked to enter VPN username and password. If connection is successfully established, you will see the following message.
Got CONNECT response: HTTP/1.1 200 CONNECTED
CSTP connected. DPD 90, Keepalive 32400
Connected tun0 as 192.168.1.139, using SSL
Established DTLS connection (using GnuTLS). Ciphersuite (DTLS1.2)-(RSA)-(AES-256-GCM).
To stop the connection, run:
sudo pkill openconnect
To run the client non-interactively, use the following syntax.
echo -n password | sudo openconnect -b vpn.example.com -u username –passwd-on-stdin
If you want to use Network Manager to manage VPN connection, then you also need to install these packages.
sudo apt install network-manager-openconnect network-manager-openconnect-gnome
If you are successfully connected to the VPN server, but your public IP address doesn’t change, that’s because IP forwarding or IP masquerading is not working. I once had a typo in my iptables command, which caused my computer not being able to browse the Internet.
Auto-Connect on System Startup
To let OpenConnect VPN client automatically connect to the server at boot time, we can create a systemd service unit.
sudo nano /etc/systemd/system/openconnect.service
Put the following lines to the file. Replace the red text.
[Unit]
Description=OpenConnect VPN Client
After=network-online.target
Wants=network-online.target
[Service]
Type=simple
ExecStart=/bin/bash -c ‘/bin/echo -n password | /usr/sbin/openconnect vpn.example.com -u username –passwd-on-stdin’
KillSignal=SIGINT
Restart=always
RestartSec=2
[Install]
WantedBy=multi-user.target
Save and close the file. Then enable this service so that it will start at boot time.
sudo systemctl enable openconnect.service
Explanation of the file content:
- After=network-online.target and Wants=network-online.target make this service run after network is up.
- In reality, this service can still run before network is up. We add Restart=always and RestartSec=2 to restart this service after 2 seconds if this service fails.
- Systemd doesn’t recognise pipe redirection, so in the ExecStart directive, we wrap the comand in single quotes and run it with the Bash shell.
- Since OpenConnect VPN client will run as a systemd service, which runs in the background, there’s no need to add -b flag to the openconnect command.
- The KillSignal directive tells Systemd to send the SIGINT signal when the systemctl stop openconnect command is issued. This will performs a clean shutdown by logging the session off, and restoring DNS server settings and the Linux kernel routing table.
To start this Systemd service immediately, run
sudo systemctl start openconnect
To stop this Systemd service, run
sudo systemctl stop openconnect
OpenConnect GUI Client for Windows and MacOS
They can be downloaded from OpenConnect GUI Github Page.
Speed
OpenConnect VPN is pretty fast. I can use it to watch 4k videos on YouTube.

Auto-Renew Let’s Encrypt Certificate
Edit root user’s crontab file.
sudo crontab -e
Add the following line at the end of the file. It’s necessary to reload ocserv service for the VPN server to pick up new certificate and key file.
@daily certbot renew –quiet && systemctl reload ocserv
Optimization
OpenConnect by default uses TLS over UDP protocol (DTLS) to achieve faster speed, but UDP can’t provide reliable transmission. TCP is slower than UDP but can provide reliable transmission. One optimization tip I can give you is to disable DTLS, use standard TLS (over TCP), then enable TCP BBR to boost TCP speed.
To disable DTLS, comment out (add # symbol at the beginning) the following line in ocserv configuration file.
udp-port = 443
Save and close the file. Then restart ocserv service.
sudo systemctl restart ocserv.service
To enable TCP BBR, please check out the following tutorial.
In my test, standard TLS with TCP BBR enabled is two times faster than DTLS.
Troubleshooting
Note that if you are using OpenVZ VPS, make sure you enable the TUN virtual networking device in VPS control panel. (If you use Vultr VPS, then you have KVM-based VPS, so you don’t have to worry about this.)
If you encounter any problem, then check OpenConnect VPN server log.
sudo journalctl -eu ocserv.service
I found that if I change port 443 to a different port, the great firewall of China will block this VPN connection.
Make OpenConnect VPN server and web server use port 443 at the same time
Normally a port can only be used by one process. However, we can use HAproxy (High Availability Proxy) and SNI (Server Name Indication) to make ocserv and Apache/Nginx use port 443 at the same time.
First, edit ocserv configuration file.
sudo nano /etc/ocserv/ocserv.conf
Uncomment the following line. This will allow ocserv to obtain the client IP address instead of HAproxy IP address.
listen-proxy-proto = true
Then find the following line.
#listen-host = [IP|HOSTNAME]
Change it to
listen-host = 127.0.0.1
This will make ocserv listen on 127.0.0.1 because later HAproxy will need to listen on the public IP address. Save and close the file. Then restart ocserv.
sudo systemctl restart ocserv
Next, we also need to make the web server listen on localhost only, instead of listening on public IP address. If you use Nginx, edit the server block file.
sudo nano /etc/nginx/conf.d/www.example.com.conf
In the SSL server block, find the following directive.
listen 443 ssl;
Change it to
listen 127.0.0.2:443 ssl;
This time we make it listen on 127.0.0.2:443 because 127.0.0.1:443 is already taken by ocserv. Save and close the file. Then restart Nginx.
sudo systemctl restart nginx
Now install HAproxy.
sudo apt install haproxy
Edit configuration file.
sudo nano /etc/haproxy/haproxy.cfg
Copy and paste the following lines to the end of the file. Replace 12.34.56.78 with the public IP address of your server. Replace vpn.example.com with the domain name used by ocserv and www.example.com with the domain name used by your web server.
frontend https
bind 12.34.56.78:443
mode tcp
tcp-request inspect-delay 5s
tcp-request content accept if { req_ssl_hello_type 1 }
use_backend ocserv if { req_ssl_sni -i vpn.example.com }
use_backend nginx if { req_ssl_sni -i www.example.com }
use_backend nginx if { req_ssl_sni -i example.com }
default_backend ocserv
backend ocserv
mode tcp
option ssl-hello-chk
server ocserv 127.0.0.1:443 send-proxy-v2
backend nginx
mode tcp
option ssl-hello-chk
server nginx 127.0.0.2:443 check
Save and close the file. Then restart HAproxy.
sudo systemctl restart haproxy
In the configuration above, we utilized the SNI (Server Name Indication) feature in TLS to differentiate VPN traffic and normal HTTPS traffic.
- When vpn.example.com is in the TLS Client Hello, HAProxy redirect traffic to the ocserv backend.
- When www.example.com is in the TLS Client Hello, HAProxy redirect traffic to the nginx backend.
- If the client doesn’t specify the server name in TLS Client Hello, then HAproxy will use the default backend (ocserv).
You can test this setup with the openssl tool. First, run the following command multiple times.
echo | openssl s_client -connect your-server-IP:443 | grep subject
We didn’t specify server name in the above command, so HAproxy will always pass the request to the default backend (ocserv), and its certificate will be sent to the client. Next, run the following two commands.
echo | openssl s_client -servername www.example.com -connect your-server-IP:443 | grep subject
echo | openssl s_client -servername vpn.example.com -connect your-server-IP:443 | grep subject
Now we specified the server name in the commands, so HAproxy will pass request accordingly. Note that the Cisco AnyConnect App doesn’t support TLS SNI, so it’s better to set ocserv as the default backend in HAProxy configuration file.
When renewing Let’s Encrypt certificate for your website, it’s recommended that you use the http-01 challenge instead of tls-alpn-01 challenge, because HAproxy is listening on port 443 of the public IP address, so it can interfere with the renew process.
sudo certbot renew –preferred-challenges http-01
Fixing HAproxy Error
If your Nginx web server doesn’t show up in your browser and you see the following messages in haproxy log (/var/log/haproxy.log)
Server nginx/nginx is DOWN, reason: Socket error, info: “Connection reset by peer
backend nginx has no server available!
Layer6 invalid response
It maybe because your backend Nginx web server is using a TLS certificate with OCSP must staple extension. Nginx doesn’t send the OCSP staple information on the first HTTP request. To make it work, be sure to add a resolver in your Nginx virtual host configuration like below.
{
….
ssl_trusted_certificate /etc/letsencrypt/live/www.example/chain.pem;
ssl_stapling on;
ssl_stapling_verify on;
resolver 8.8.8.8;
….
}
Save and close the file. Then restart Nginx.
sudo systemctl restart nginx
Also consider removing health check for the backend server in HAproxy. So change
server nginx 127.0.0.2:443 check
To
server nginx 127.0.0.2:443
Save and close the file. Then restart HAproxy.
sudo systemctl restart haproxy
How to Disable TLS 1.0 and TLS 1.1 in ocserv
The PCI council deprecated TLS 1.0 in June 30, 2018 and main stream web browsers are going to disable TLS 1.0 and TLS 1.1 in 2020. We should do the same with VPN server. Edit the main configuration file.
sudo nano /etc/ocserv/ocserv.conf
Find the following line:
tls-priorities = “NORMAL:%SERVER_PRECEDENCE:%COMPAT:-RSA:-VERS-SSL3.0:-ARCFOUR-128”
To disable TLS 1.0 and TLS 1.1 in OpenConnect VPN server, just add -VERS-TLS1.0 and -VERS-TLS1.1 in the line.
tls-priorities = “NORMAL:%SERVER_PRECEDENCE:%COMPAT:-RSA:-VERS-SSL3.0:-ARCFOUR-128:-VERS-TLS1.0:-VERS-TLS1.1”
Save and close the file. Then restart ocserv.
sudo systemctl restart ocserv
Now ocserv will only accept TLS 1.2. For further information on configuring the TLS parameter in ocserv, please see GnuTLS priority strings.
To check if TLS 1.0 is supported in your OpenConnect VPN server, run the following command.
openssl s_client -connect vpn.your-domain.com:443 -tls1
And check TLS 1.1
openssl s_client -connect vpn.your-domain.com:443 -tls1_1
If you see the following message in the output, that means the TLS version is not supported.
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Note: The ocserv package on Ubuntu 20.04 supports TLS 1.3.
Per User or Per Group Configuration
Ocserv allows per user and per group configurations. To enable this feature, uncomment the following two lines in /etc/ocserv/ocserv.conf file.
config-per-user = /etc/ocserv/config-per-user/
config-per-group = /etc/ocserv/config-per-group/
Save and close the file. Then create the per user and per-group config directory.
sudo mkdir /etc/ocserv/config-per-user/
sudo mkdir /etc/ocserv/config-per-group/
Next, you can create a file under these two directories. For example, create the user1 file to allow custom configuration for user1.
sudo nano /etc/ocserv/config-per-user/user1
You can also create the group1 file to allow custom configuration for the group named group1.
sudo nano /etc/ocserv/config-per-group/group1
You can add something like below in the file.
route = 10.10.10.0/255.255.255.0
tunnel-all-dns = false
dns = 8.8.8.8
dns = 1.1.1.1
Where:
- The first line means that after user1 or users in group1 connect to this VPN server, only traffic to the 10.10.10.0/24 network will be routed via VPN server. Traffic to other IP addresses are routed via the original gateway.
- The second line disables tunneling DNS queries.
- The third and fourth line set DNS servers for VPN clients.
I use this trick to allow my another VPS (virtual private server) to connect to this VPN server without disrupting normal traffic, so the TUN device (vpns0) of my VPN server is always turned on, which means my VPN server will always have the private IP address 10.10.10.1.
Save and close the file. Restart ocserv for the changes to take effect.
sudo systemctl restart ocserv
Wrapping Up
That’s it! I hope this tutorial helped you install and configure OpenConnect VPN on Ubuntu 20.04. As always, if you found this post useful, then subscribe to our free newsletter to get more tips and tricks
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