#Instalasi OpenVPN Client di Linux

Install aplikasi GUI utuk client

# apt-get install kvpnc
# apt-get install network-manager-openvpn openvpn

Copy setting OpenVPN

# cp -Rf /usr/share/doc/openvpn/examples/easy-rsa/* /etc/openvpn/

Pada Ubuntu Hardy 8.04 tampaknya ada beberapa versi konfigurasi, kita dapat menggunakan salah satu dengan cara

# cp -Rf /etc/openvpn/2.0/* /etc/openvpn/

Selanjutnya lakukan langkah berikut, yang sama dengan versi lainnya

# cd /etc/openvpn
# mkdir /etc/openvpn/keys

Lakukan langkah berikut

# vi vars
# , ./vars
# ./clean-all

Atau copy file /etc/openvpn/vars dari Server. Copy key client dari Server

# scp -r root@192.168.0.3:/etc/openvpn/keys/ca.crt /etc/openvpn/keys
# scp -r root@192.168.0.3:/etc/openvpn/keys/user1.crt /etc/openvpn/keys
# scp -r root@192.168.0.3:/etc/openvpn/keys/user1.key /etc/openvpn/keys

Menjalankan VPN Client (client.conf from www.openvpn.org)

# openvpn --config /etc/openvpn/client.conf

Contoh Client.conf adalah sebagai berikut,

# vi /etc/openvpn/client.conf

isinya kurang lebih

# Specify that we are a client and that we
# will be pulling certain config file directives
# from the server.
client

# Use the same setting as you are using on
# the server.
# On most systems, the VPN will not function
# unless you partially or fully disable
# the firewall for the TUN/TAP interface.
; dev tap
dev tun

# Windows needs the TAP-Win32 adapter name
# from the Network Connections panel
# if you have more than one.  On XP SP2,
# you may need to disable the firewall
# for the TAP adapter.
; dev-node MyTap

# Are we connecting to a TCP or
# UDP server?  Use the same setting as
# on the server.
;proto tcp
proto udp

# The hostname/IP and port of the server.
# You can have multiple remote entries
# to load balance between the servers.
;remote my-server-1 1194
;remote my-server-2 1194
remote 192.168.0.3 1194

# Choose a random host from the remote
# list for load-balancing.  Otherwise
# try hosts in the order specified.
;remote-random

# Keep trying indefinitely to resolve the
# host name of the OpenVPN server.  Very useful
# on machines which are not permanently connected
# to the internet such as laptops.
resolv-retry infinite

# Most clients don't need to bind to
# a specific local port number.
nobind

# Try to preserve some state across restarts.
persist-key
persist-tun

# If you are connecting through an
# HTTP proxy to reach the actual OpenVPN
# server, put the proxy server/IP and
# port number here.  See the man page
# if your proxy server requires
# authentication.
;http-proxy-retry # retry on connection failures
;http-proxy [proxy server] [proxy port #]

# Wireless networks often produce a lot
# of duplicate packets.  Set this flag
# to silence duplicate packet warnings.
;mute-replay-warnings

# SSL/TLS parms.
# See the server config file for more
# description.  It's best to use
# a separate .crt/.key file pair
# for each client.  A single ca
# file can be used for all clients.
ca keys/ca.crt
cert keys/client.crt
key keys/client.key

# Verify server certificate by checking
# that the certicate has the nsCertType
# field set to "server".  This is an
# important precaution to protect against
# a potential attack discussed here:
#  http://openvpn.net/howto.html#mitm
#
# To use this feature, you will need to generate
# your server certificates with the nsCertType
# field set to "server".  The build-key-server
# script in the easy-rsa folder will do this.
;ns-cert-type server

# If a tls-auth key is used on the server
# then every client must also have the key.
;tls-auth ta.key 1

# Select a cryptographic cipher.
# If the cipher option is used on the server
# then you must also specify it here.
;cipher x
;cipher AES-128-CBC

# Enable compression on the VPN link.
# Don't enable this unless it is also
# enabled in the server config file.
; comp-lzo

# Set log file verbosity.
verb 3

# Silence repeating messages
;mute 20

Cara menjalankan VPN client dengan client.conf (from www.openvpn.org)

# openvpn --config /etc/openvpn/client.conf