1 IPSec Lab

2 Install openvpn To install openvpn type: To install openvpn type: yum install openvpnyum install openvpn Note: both openvpn and lzo are installed Note: both openvpn and lzo are installed To see what they are type: To see what they are type: rpm –qi openvpnrpm –qi openvpn rpm –qi lzorpm –qi lzo rpm –qi opensslrpm –qi openssl

3 Set Up Determine who’s left and who’s right Determine who’s left and who’s right Exchange IP addresses Exchange IP addresses Ping each others address to make sure you have connectivity Ping each others address to make sure you have connectivity Verify /dev/net/tun device file was created Verify /dev/net/tun device file was created Create an account for your partner using useradd and passwd Create an account for your partner using useradd and passwd

4 Check/Set Firewall Check to see if firewall is running: Check to see if firewall is running: iptables –L -niptables –L -n Insert firewall rule to allow VPN Insert firewall rule to allow VPN iptables -I RH-Firewall-1-INPUT -p udp --dport j ACCEPTiptables -I RH-Firewall-1-INPUT -p udp --dport j ACCEPT

5 VPN Configuration Change to the following directory: Change to the following directory: /usr/share/doc/openvpn-2.1//usr/share/doc/openvpn-2.1/ Look around…lot’s of information here Look around…lot’s of information here Change into the sample-config-files directory Change into the sample-config-files directory For the purpose of simplicity we will use config files posted on wildbill.org For the purpose of simplicity we will use config files posted on wildbill.org right = right.conf.txtright = right.conf.txt left = left.conf.txtleft = left.conf.txt Copy the right or left config files to /etc/openvpn (depending if you were right or left)Copy the right or left config files to /etc/openvpn (depending if you were right or left)

6 VPN Configuration Rename the conf file you downloaded to openvpn.conf Rename the conf file you downloaded to openvpn.conf Now we will edit the /etc/openvpn/openvpn.conf file Now we will edit the /etc/openvpn/openvpn.conf file Only the left file needs to be changed by adding the ip address of the right Only the left file needs to be changed by adding the ip address of the right

7 VPN Configuration Now one of you has to generate a shared key that will encrypt the tunnel Now one of you has to generate a shared key that will encrypt the tunnel openvpn --genkey --secret static.keyopenvpn --genkey --secret static.key Now copy that to your partner’s PC Now copy that to your partner’s PC He can then (as root) copy it into the /etc/openvpn directory He can then (as root) copy it into the /etc/openvpn directory Note: the same static.key file must be in both /etc/openvpn directories Note: the same static.key file must be in both /etc/openvpn directories

8 Starting the VPN On both servers type: On both servers type: service openvpn startservice openvpn start Check to see if the tunnel interface came up: Check to see if the tunnel interface came up: ifconfigifconfig You should see an interface called tun0 You should see an interface called tun0 Now try pinging each other Now try pinging each other ping from the leftping from the left ping from the rightping from the right

9 Check the Connection Using tcpdump you can verify the connection Using tcpdump you can verify the connection start a ping from one side to xstart a ping from one side to x while on the other side start a tcpdump against the tunnel interfacewhile on the other side start a tcpdump against the tunnel interface tcpdump –I tun0 tcpdump –I tun0 And against unencrypted interfaceAnd against unencrypted interface tcpdump –I eth0 host tcpdump –I eth0 host

10 More OpenVPN information Home Page: Home Page: Howto Howto Other VPN applications: Other VPN applications: Free S/WAN ( S/WAN ( Stunnel ( (

11 An alternate reality