The document provides detailed instructions for setting up an OpenVPN server on a Linux system, specifically focusing on the configuration of DHCP, server keys, and client certificates. It covers essential steps such as installing OpenVPN, configuring network settings, and generating required cryptographic keys for both server and client connections. Additionally, it emphasizes testing the VPN and ensuring that user access is managed correctly.

1. NETWORK ADMINISTRATION
OpenVPN Server on Linux
2013-2015
PASSERELLES NUMERIQEUS CAMBODIA
Street 371 Phum Tropeang Chhuk (Borey Sorla), Sangkat Tek Thia Khan Sek Sok P.O. Box 511 Phnom Penh,
Cambodia

2. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 1
CONTENTS
LAB Instruction ..........................................................................................................................2
Windows......................................................................................Error! Bookmark not defined.
Install DHCP service..................................................................Error! Bookmark not defined.
Create DCHP Scope...................................................................Error! Bookmark not defined.
Exclude IP address amount 10 IP addresses .............................Error! Bookmark not defined.
Configure DHCP Option ............................................................Error! Bookmark not defined.
IP address Reservation..............................................................Error! Bookmark not defined.
Deny Client by filter Mac address .............................................Error! Bookmark not defined.
Create New scope for LAN-Client .............................................Error! Bookmark not defined.
Show DHCP audit log file ..........................................................Error! Bookmark not defined.
Suse Linux....................................................................................Error! Bookmark not defined.
Adding more NICs and Assign IP address...............Error! Bookmark not defined.
Install DHCP Relay Service ...........................................Error! Bookmark not defined.
Configure DHCP Relay Service.....................................Error! Bookmark not defined.
Let client request IP address........................................Error! Bookmark not defined.
Make sure between LAN client and Windows Server can:.. Error! Bookmark
not defined.

3. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 2
LAB INSTRUCTION
SUSE LINUX ENTERPRISE SERVER 11
 LAN VPN Server
 Network Address: 192.168.102.0/24
 192.168.1.1 Router/Default Gateway
 192.168.1.1 DNS Server
 WAN
 Network address: 203.100.10.0/24
 203.100.10.1 Router/Default Gateway
 192.168.1.10 DNS Server
 172.16.120.3 – 172.16.120.254 Address pool/scope
 172.16.120.10 – 172.16.120.20 Address Exclusive
 Make sure the you have configure the hostname and ip address
of different LAN and WAN

4. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 3

5. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 4
1. Install Service OpenVPN

6. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 5
2. Configure VPN Server
a. Copy “ëasy-rsa” from /usr/share/openvpn/easy-rsa to “/etc/openvpn”
b. Generate the server key by go to /etc/openvpn and generate

7. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 6
c. Edit and change the certificate attribute by go to /etc/openvpn/easy-rsa/vars

8. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 7
d. Define keys directory

9. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 8
e. Generation of the key (by cryptography method Diffie-Hellman with dh1024
bit)
f. Generation of key and certificate to authority of certification
- Create new user for vpn and client for generate the email address

10. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 9
g. Generation of key and certificate to the server //information mixed with key
to create certificate then store in Server
h. Edit /etc/openvpn/easy-rsa/server.conf by changing

11. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 10
- Ca ca.crt -> ca /etc/openvpn/easy-rsa/keys/ca.crt
- Cert server.crt -> cert /etc/openvpn/easy-rsa/keys/vpnserver.crt
- key server.key -> server.key /etc/openvpn/easy-rsa/keys/vpnserver.key
- dh dh1024.perm -> dh /etc/openvpn/easy-rsa/keys/dh1024.pem
- ;cipher DES-EDE3-CBC -> cipher DES-EDE3-CBC(encryption method)

12. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 11

13. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 12
i. Generation of the keys and certificate to the client (for tola.leng user)

14. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 13

15. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 14
3. Install/Configure OpenVPN Client

16. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 15

17. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 16
-copy file ca.crt, tola.leng.crt, tola.leng.key to input into the configuration file and input the
certificate into C:Program FilesOpenVPNbin..........
-copy file client.ovpn to the folder config
-change configuration file client.ovpn

18. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 17

19. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 18
-Finally save the file after we edit the information there are:
remote 203.100.10.1 1194
;remote 203.100.10.1 1194
ca "C:Program FilesOpenVPNbinca.crt"
cert "C:Program FilesOpenVPNbintolaleng.crt"
key "C:Program FilesOpenVPNbintolaleng.key"
cipher DES-EDE3-CBC

20. PASSERELLESNUMERIQUES CAMBODIA NETWORK ADMINISTRATION
TOLA.LENG-PC 19
4. Testing OpenVPN remotes
5. Testing to access File Server
6. Set only one user can remote in the same time.
The End!