Posts tagged Linux

Yesterday I decided to setup a vpn server so a friend and I could play some coop mode on call of duty 5. This was so easy to setup I thought I would share it with the rest of the world:

Step 1.  Installing pptpd – the pptpd is the daemon that runs the pptp server. To install this just use apt-get:

$ apt-get install ssh pptpd -y

Step2. Next you will need to modify the pptpd.conf

$ vi /etc/pptpd.conf

Then scroll down to the bottom and modify the following lines with the subnets you would like assigned:

# (Recommended)
#localip 192.168.0.1
#remoteip 192.168.0.234-238,192.168.0.245
# or
localip 192.168.2.0
remoteip 192.168.2.2-238,192.168.2.245

Step 3. The vpn server is now configured and now you must setup authenticated users:

$ vi /etc/ppp/chap-secrets

The config file is very straight forward and I have an example of a user included:

# Secrets for authentication using CHAP
# client        server  secret                  IP addresses
clown           pptpd  bigshoes               "*"

Step 4. When pptpd was installed it started automatically so we will need to restart it to apply the changes:

$ /etc/init.d/pptpd restart

Then just to make sure all is good lets check to make sure the service is listening:

 $ netstat -anp | grep pptpd
tcp        0      0 0.0.0.0:1723            0.0.0.0:*               LISTEN      7565/pptpd
unix  2      [ ]         DGRAM                    15781    7565/pptpd

If you see a listen on port 1723 you are ready to connect.

Optional: Now, if you would like to add internet access over this vpn, you can do this:

 $ vi /etc/sysctl.conf

and find the line for ipv4 forwarding and make sure it = 1:

# Uncomment the next line to enable packet forwarding for IPv4
net.ipv4.ip_forward=1

The use iptables to get the net forwarded:

$ /sbin/iptables -P FORWARD ACCEPT
$ /sbin/iptables --table nat -A POSTROUTING -o eth0 -j MASQUERADE

Optionally you can install bind9 and have a DNS resolver you can use for the vpn connection:

$ apt-get install bind9 -y

Then start it:

$ /etc/init.d/bind9 start

The configuration of the vpn client that is connecting can be modified to use this DNS resolver now to allow for more control.

Connecting to the vpn from a Windows 7 client ( Click images to zoom in):

Step 1. Open the Network and Sharing center

Step 2. Set up a new connection or network

Step 3. Connect to a workplace

Step 4. No create a new connection if other connections exist

Step 5. Use my internet cconnection:

Step 6. Enter the internet address and name of the vpn connection

Step 7. Enter the username and password:

Step 8. Connect!!

This should pretty much cover all you need for the installation of a basic Debian or Ubuntu PPTP vpn server. Enjoy!