vpn client setup
http://www.cyberciti.biz/tips/howto-configure-ubuntu-fedora-linux-pptp-client.html
Linux configure point to point tunneling PPTP VPN client for Microsoft PPTP vpn server
by Vivek Gite on June 11, 2007
in FreeBSD, Howto, Linux, Linux distribution, Linux laptop, Linux login control, Networking, OpenBSD, RedHat/Fedora Linux, Security, Sys admin, Tips, Troubleshooting, Ubuntu Linux, Windows server
With this tip you will be able to work from home using VPN and that too from Linux / FreeBSD system for the proprietary Microsoft Point-to-Point vpn server.
Different organization uses different VPN connection options such as SSL, PPTP or IPSEC. When you need to access corporate network and its services, you need to login using VPN.
The Point-to-Point Tunneling Protocol (PPTP) is a method for implementing virtual private networks. It works on Data link layer (#2 layer) on TCP/IP model. Personally I prefer IPSEC. PPTP Client is a Linux, FreeBSD, NetBSD and OpenBSD client for the proprietary Microsoft Point-to-Point Tunneling Protocol, PPTP. Allows connection to a PPTP based Virtual Private Network (VPN) as used by employers and some cable and ADSL internet service providers.
But many originations use PPTP because it is easy to use and works with Windows, Mac OS X, Linux/*BSD and other handled devices.
Compatibility note
I’ve tested instructions and pptp on:
[a] CentOS / RHEL / Fedora Core Linux running 2.6.15+ kernel
[b] Ubuntu and Debian Linux running 2.6.15+ kernel
[c] FreeBSD etc
I've found that pptp client is 100% compatible with the following servers/products:
[a] Microsoft Windows VPN Server
[b] Linux PPTP Server
[c] Cisco PIX etc
How do I install PPTP client under Linux?
By default most distro installs PPTP client called PPTP-linux which is the client for the proprietary Microsoft Point-to-Point Tunneling. Use apt-get or yum command to install pptp client:
$ sudo apt-get install pptp-linux network-manager-pptp
Fedora Core user can install client using rpm command:
# rpm -Uvh http://pptpclient.sourceforge.net/yum/stable/fc6/pptp-release-current.noarch.rpm
# yum --enablerepo=pptp-stable install pptpconfig
[a] network-manager-pptp or pptpconfig - A gui network management framework (PPTP plugin) for network-admin tool (frontend)
[b] pptp-linux - Point-to-Point Tunneling Protocol (PPTP) command line client
How do I configure client using command line (cli)?
You need to edit / create following configuration files
/etc/ppp/chap-secrets - Add your login name / password for authentication using CHAP. Pppd stores secrets for use in authentication in secrets files.
/etc/ppp/peers/myvpn-name - A dialup connection authenticated with PAP / CHAP configuration file. You need to add your dialup server name and other information in this file.
Sample configuration data
PPTP server name: pptp.vpn.nixcraft.com
VPN User Name : vivek
VPN Password: VpnPassword
Connection name: delhi-idc-01
Open /etc/ppp/chap-secrets file:
# vi /etc/ppp/chap-secrets
OR
$ sudo vi /etc/ppp/chap-secrets
Append line as follows:
vivek PPTP VpnPassword *
Save and close the file.
Create a connection file called /etc/ppp/peers/delhi-idc-01 (replace delhi-idc-01 with your connection name such as office or vpn):
# vi /etc/ppp/peers/delhi-idc-01
Append configuration data as follows:
pty "pptp pptp.vpn.nixcraft.com --nolaunchpppd"
name vivek
remotename PPTP
require-mppe-128
file /etc/ppp/options.pptp
ipparam delhi-idc-01
Close and save the file. Where,
pty "pptp pptp.vpn.nixcraft.com --nolaunchpppd": Specifies that the command script is to be used to communicate rather than a specific terminal device. Pppd will allocate itself a pseudo-tty master/slave pair and use the slave as its terminal device. The script will be run in a child process with the pseudo-tty master as its standard input and output. An explicit device name may not be given if this option is used. (Note: if the record option is used in conjunction with the pty option, the child process will have pipes on its standard input and output.). In this case we are using pptp client to establishes the client side of a Virtual Private Network (VPN) using the Point-to-Point Tunneling Protocol (PPTP). pptp.vpn.nixcraft.com is my host name (or IP address) for the PPTP server. --nolaunchpppd option means do not launch pppd but use stdin as the network connection. Use this flag when including pptp as a pppd connection process using the pty option.
name vivek: VPN username
remotename PPTP: Set the assumed name of the remote system for authentication purposes to name. If you don't know name ask to network administrator
require-mppe-128: Require the use of MPPE, with 128-bit encryption. You must encrypt traffic using encryption.
file /etc/ppp/options.pptp: Read and apply all pppd options from options.pptp file. Options used by PPP when a connection is made by a PPTP client.
ipparam delhi-idc-01 : Provides an extra parameter to the ip-up, ip-pre-up and ip-down scripts (optional).
Route traffic via ppp0
To route traffic via PPP0 interface add following route command to /etc/ppp/ip-up.d/route-traffic
# vi /etc/ppp/ip-up.d/route-traffic
Append following sample code (modify NET an IFACE as per your requirments):
#!/bin/bash
NET="10.0.0.0/8" # set me
IFACE="ppp0" # set me
#IFACE=$1
route add -net ${NET} dev ${IFACE}
Save and close the file:
# chmod +x /etc/ppp/ip-up.d/route-traffic
Task: connect to PPTP server
Now you need to dial out to your office VPN server. This is the most common use of pppd. This can be done with a command such as:
# pppd call delhi-idc-01
If everything is went correctly you should be online and ppp0 should be up. Remote server will assign IP address and other routing information. Here is the message from my /var/log/messages file:
# tail -f /var/log/messages
