OpenVPN: IPv4 /32 single client
sumber: https://www.ostechnix.com/easiest-way-install-configure-openvpn-server-linux/
Topology
CLIENT 1 ------- HOST A ---------------- HOST B --------- CLIENT 2
ovpn server ovpn client
Host A akan berfungsi sebagai OpenVPN Server.
OS : Ubuntu 18.04 IP : 192.168.0.239/24 hostname : vpnserver
Host B akan berfungsi sebagai OpenVPN client
OS : Ubuntu 18.04 IP : 192.168.0.237/24
Instal & Konfigurasi OpenVPN Server
Download script openvpn-install dari github
cd /usr/local/src wget https://git.io/vpn -O openvpn-install.sh bash openvpn-install.sh
Jawab pertanyaan:
IP address: 192.168.0.239 Public IP address / hostname: vpnserver Protocol [1-2]: 1 -- UDP Port: 1194 DNS [1-5]: 1 Client name: client Press any key to continue... <ENTER>
Maka akan tampak file client.ovpn, di
/root/client.ovpn
Copykan ke client
scp client.ovpn root@192.168.0.237:/etc/openvpn/
Konfigurasi OpenVPN Client
Pastikan openvpn terinstalsi
apt install openssh-server openvpn
Jalankan OpenVPN client
cd ~ sudo su openvpn --config client.ovpn
Sample output:
Now, check if tun0(VPN interface) is created, and check the VPN interface IP address using ‘ip addr’ command:
ip addr
Sample output:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 08:00:27:28:98:6b brd ff:ff:ff:ff:ff:ff inet 192.168.43.199/24 brd 192.168.43.255 scope global dynamic enp0s3 valid_lft 42359sec preferred_lft 42359sec inet6 fe80::a00:27ff:fe28:986b/64 scope link valid_lft forever preferred_lft forever 3: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 100 link/none inet 10.8.0.2/24 brd 10.8.0.255 scope global tun0 valid_lft forever preferred_lft forever
As you can see in the above output, Our VPN server automatically assigned an IP address 10.8.0.2 to the VPN client.
Now, try to ping the VPN server from your VPN client system:
ping -c3 10.8.0.1
Sample output:
PING 10.8.0.1 (10.8.0.1) 56(84) bytes of data. 64 bytes from 10.8.0.1: icmp_seq=1 ttl=64 time=1.05 ms 64 bytes from 10.8.0.1: icmp_seq=2 ttl=64 time=1.94 ms 64 bytes from 10.8.0.1: icmp_seq=3 ttl=64 time=2.49 ms --- 10.8.0.1 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2001ms rtt min/avg/max/mdev = 1.057/1.832/2.495/0.594 ms
Congratulations! We have now successfully installed and configured OpenVPN server and client in CentOS. This method is same for DEB based systems such as Ubuntu and Linux Mint. Unlike the manual installation, this script makes the the openvpn installation and configuration much easier.
Cheers!