DD-WRT OpenVPN Daemon Settings

http://pantestmb.blogspot.ro/2013/04/dd-wrt-openvpn-router-to-router.html
http://pantestmb.blogspot.ro/2013/04/setup-openvpn-client-to-connect-to-dd.html

Services
VPN
OpenVPN Daemon
OpenVPN Config : 

# Servers LAN route 
## Push route to server subnet onto all clients
push "route 192.168.61.0 255.255.255.0"
#
## Clients LAN route 
route 192.168.101.0 255.255.255.0 172.16.0.2
route 192.168.33.0 255.255.255.0 172.16.0.2
route 192.168.62.0 255.255.255.0 172.16.0.2
route 192.168.15.0 255.255.255.0 172.16.0.2
#
## Bug workaround, this is fixed in r17685
client-config-dir /tmp/openvpn/ccd
#
server 172.16.0.0 255.255.0.0
dev tun0
proto tcp
keepalive 10 120
dh /tmp/openvpn/dh.pem
ca /tmp/openvpn/ca.crt
cert /tmp/openvpn/cert.pem
key /tmp/openvpn/key.pem
management localhost 5001

Administration
Commands
Startup

mkdir -p /tmp/openvpn/ccd
echo "iroute 192.168.15.0 255.255.255.0" > /tmp/openvpn/ccd/bac15cli4res
echo "iroute 192.168.33.0 255.255.255.0" > /tmp/openvpn/ccd/dev03cli4res
echo "iroute 192.168.62.0 255.255.255.0" > /tmp/openvpn/ccd/buc06cli4res

Firewall

iptables -I INPUT -p tcp --dport 1194 -j ACCEPT
iptables -I INPUT -p tcp --source 192.168.61.0/24 -j ACCEPT
iptables -I INPUT -p tcp --source 192.168.101.0/24 -j ACCEPT
iptables -I INPUT -p tcp --source 172.16.0.0/16 -j ACCEPT
iptables -I INPUT -i tun0 -p icmp -j ACCEPT
iptables -I FORWARD --source 172.16.0.0/16 -p icmp -j ACCEPT
iptables -I FORWARD --source 192.168.15.0/24 -p icmp -j ACCEPT
iptables -I FORWARD --source 192.168.61.0/24 -p icmp -j ACCEPT
iptables -I FORWARD --source 192.168.62.0/24 -p icmp -j ACCEPT
iptables -I FORWARD --source 192.168.101.0/24 -p icmp -j ACCEPT
iptables -I FORWARD -p tcp --source 172.16.0.0/16 -j ACCEPT
iptables -I FORWARD -p tcp --source 192.168.101.0/24 -j ACCEPT
iptables -I FORWARD -p tcp --source 192.168.61.0/24 -j ACCEPT
iptables -I FORWARD -i br0 -o tun0 -j ACCEPT
iptables -I FORWARD -i tun0 -o br0 -j ACCEPT

If there is a gateway server - a routing command can be used :
route add -net 192.168.15.0 netmask 255.255.255.0 gw 192.168.16.49

DD-WRT OpenVPN Router To Router

Client Configuration - DD-WRT

This is the configuration for an OpenVPN Client running on another DD-WRT box.

Just set the OpenVPN server name (its WAN address or name) and port (1194) using the GUI, and then put in the certs similar to the procedure on the server:

Box	File to insert
Public Server Cert	ca.crt
Public Client Cert	suc19cli4res.crt
Private Client Key	suc19cli4res.key

build-key suc19cli4res

Setup OpenVPN Client to connect to DD-WRT OpenVPN Service

Setup OpenVPN Client to connect to DD-WRT OpenVPN Service

We consider that we have an ASUS RT-N16 wireless router with the following firmware installed :
" DD-WRT v24-sp2 (08/07/10) vpn "

( some day  I will write an article about how I've installed DD-WRT firmware and configured OpenVPN service in ASUS RT-N16 ) 

First of all , we must choose to install a stable OpenVPN version : 2.1.4 ;
Can be downloaded from : 

http://openvpn.net/index.php/open-source/downloads/471-old-releases.html

http://swupdate.openvpn.org/community/releases/openvpn-2.1.4-install.exe
After installation , OpenVPN-GUI can be run as administrator if there are problems ; 

Setting up OpenVPN Client to connect to DD-WRT OpenVPN Service we have to create or to already have : 

1) a configuration file ("ita2cli4resita2asus.ovpn")
2) a router certificate  ("ca_resita2asus.crt")
3) a openvpn client certificate ("ita02cli4res.crt")
4) a client key file = ("ita02cli4res.key")

We can follow the steps from : howtogeek.com

The problem in that article is that after you create some keys and certificates and if after 

a while you want to create for one more user , you have to recreate all the keys and certificates for all client users ... 

So , lets see the steps to create config , key and certificate for one client user ; 

Then close the command window , restart Windows and after that try to create just one more : 

Let's assume that we are using Windows 7 - 64 bit edition ;

Under Accessories there is "Command Prompt" ;
Right click on it and click Run as administrator.

DO RUN : "cd c:\Program Files (x86)\OpenVPN\easy-rsa"

( open-vpn client 32 bit edition on a Windows 7 64 bit ) 

for the last client , created after a Windows restart

do not run : "init-config"

do not edit vars.bat file   

do not run : "clean-all"

DO RUN : "build-key ita02cli4res"

Just be sure to enter ita02cli4res as the Common Name when prompted. 

We don't have to recreate the server key : 

do not run : build-key-server server

do not run :  build-dh