HOWTO OpenVPN Setup Guide For FC3, FC4, FC5, CentOS And Others,connecting Via Windows

I have had great difficulty in setting up OpenVPN, so I thought, when I finally do get it to work, I will write a HOWTO, so other can hopefully benefit…

This guide was done using a FC4 VPS, running on Xen, it will work on OpenVZ, all you need to do is ask your VPS provider to install “tun support”.

1.First of all get a few additional repos, If you already have your repos setup, skip this step

If you have Fedora 3, follow these steps,

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If you have Fedora 4, follow these steps,

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If you have Fedora 5, follow these steps,

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If you have CentOS, follow the “additional third party CentOS repos”

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Then issue these commands, each line is a new command, anything beginning with "#" are comments so dont try to execute those.

Code:
yum update

yum install openssl openssl-devel
# openssl and openssl-devel may be installed already… so don’t worry

2. Right, now you want to install OpenVPN, here are the commands,

Code:
yum install openvpn -y

#Now check that it works

service openvpn start
service openvpn stop

3. A few things to setup before you can make certificates, issue these commands,

Code:

find / -name "easy-rsa"

#you should get an output like this…

/usr/share/doc/openvpn-2.0.7/easy-rsa

#Now, make a copy of the easy-rsa directory, to /etc/openvpn/ ( make sure you #have put the right version number in i.e. mine was -2.0.7, change if needed)

cp -R /usr/share/doc/openvpn-2.0.7/easy-rsa /etc/openvpn/

cd /etc/openvpn/easy-rsa

chmod 777 *

mkdir /etc/openvpn/keys

4. You need to edit the vars file, located in /etc/openvpn/easy-rsa
You can use any editor you like, I used vi.

Change the line

Code:
export KEY_DIR=$D/keys
to

Code:
export KEY_DIR=/etc/openvpn/keys
Also at the bottom of this file you will see something similar to this,

Code:
export KEY_COUNTRY=US
export KEY_PROVINCE=CA
export KEY_CITY=SOMEWHERE
export KEY_ORG="My Org"
export KEY_EMAIL=me@mydomain.com
Change this to your own values.

5. Now its time to make the certificates, enter these commands

Code:
. ./vars

Code:
./clean-all

Code:
./build-ca
# just hit enter to the defaults apart from Common Name, this must be unique
# call it something like mydomain-ca

Code:
./build-key-server server

Code:
./build-key client1
# remember that common name must be unique e.g. use mydomain-client1
# and YES you want to sign the keys

Code:
./build-key client2
# do this step for as many clients as you need.

Code:
./build-dh

6. We are almost done now… right we need to create a few config files, you can download my template from here,

Code:
cd /etc/openvpn

Code:
wget www.designpc.co.uk/downloads/server.conf
# make sure you change a few things in the server.conf file, like DNS
# servers

Code:
touch server-tcp.log
~ this makes the log file..

Code:
touch ipp.txt
this makes the IP reservation list.

7. You need to make a few changes to OpenVPN itself. Go to..

Code:
cd /etc/init.d/
edit the openvpn file

#Uncomment this line (line 119)

Code:
echo 1 > /proc/sys/net/ipv4/ip_forward
Add these lines below it, changing 123.123.123.123 to your public IP address,

Code:
iptables -t nat -A POSTROUTING -s 192.168.2.3 -j SNAT --to 123.123.123.123
iptables -t nat -A POSTROUTING -s 192.168.2.4 -j SNAT --to 123.123.123.123
iptables -t nat -A POSTROUTING -s 192.168.2.5 -j SNAT --to 123.123.123.123
iptables -t nat -A POSTROUTING -s 192.168.2.6 -j SNAT --to 123.123.123.123
iptables -t nat -A POSTROUTING -s 192.168.2.7 -j SNAT --to 123.123.123.123
iptables -t nat -A POSTROUTING -s 192.168.2.8 -j SNAT --to 123.123.123.123
iptables -t nat -A POSTROUTING -s 192.168.2.9 -j SNAT --to 123.123.123.123
iptables -t nat -A POSTROUTING -s 192.168.2.10 -j SNAT --to 123.123.123.123
Now install iptables if you don’t have it already,

Code:
yum install iptables

#test it

service iptables start
service iptables stop

8. Now for the client config files. If your client is a Windows machine, make sure you have installed OpenVPN, use the gui version, downloadable from here;

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You need to copy a few files from the server to your client machine, here is the list, located in /etc/openvpn/keys/

## WARNING ## Use a secure way of transferring these files off the server, something like WinSCP.

ca.crt
client1.csr
client1.key
client1.crt

Put these files in this directory C:Program FilesOpenVPNconfig

Now you need to make a client config, here is an example..

PHP Code:

clientdev tunproto tcp#Change my.publicdomain.com to your public domain or IP addressremote my.publicdomain.com 1194resolv-retry infinitenobindpersist-keypersist-tunca ca.crtcert client1.crtkey client1.keyns-cert-type server#DNS Options here, CHANGE THESE !!push "dhcp-option DNS 123.123.123.123"push "dhcp-option DNS 123.123.123.124"comp-lzoverb 3 

Make sure you edit any of the lines with comments above them.

Call this file client1.opvn and put it in C:Program FilesOpenVPNconfig

Make sure the file extension is .opvn not .txt

To connect right click on OpenVPN in the taskbar >> Connect

To test ping 192.168.2.1