Jan Just Keijser, Eric F. Crist
Format: PDF / Kindle (mobi) / ePub
Security on the internet is increasingly vital to both businesses and individuals. Encrypting network traffic using Virtual Private Networks is one method to enhance security. The internet, corporate, and “free internet” networks grow more hostile every day. OpenVPN, the most widely used open source VPN package, allows you to create a secure network across these systems, keeping your private data secure. The main advantage of using OpenVPN is its portability, which allows it to be embedded into several systems.
This book is an advanced guide that will help you build secure Virtual Private Networks using OpenVPN. You will begin your journey with an exploration of OpenVPN, while discussing its modes of operation, its clients, its secret keys, and their format types. You will explore PKI: its setting up and working, PAM authentication, and MTU troubleshooting. Next, client-server mode is discussed, the most commonly used deployment model, and you will learn about the two modes of operation using "tun" and "tap" devices.
The book then progresses to more advanced concepts, such as deployment scenarios in tun devices which will include integration with back-end authentication, and securing your OpenVPN server using iptables, scripting, plugins, and using OpenVPN on mobile devices and networks.
Finally, you will discover the strengths and weaknesses of the current OpenVPN implementation, understand the future directions of OpenVPN, and delve into the troubleshooting techniques for OpenVPN.
By the end of the book, you will be able to build secure private networks across the internet and hostile networks with confidence.
click on Initialize eToken. This will bring up the following dialog box: Fill in the token password and administrator password, uncheck the Token Password must be changed on first logon checkmark, and click on Start. All contents on the token will now be destroyed and the eToken will be initialized with the new token and administrator passwords. Generating a certificate/private key pair When using a hardware token, the process of generating a certificate and private key pair is a
The traffic leaving the eth0 interface has its source address rewritten so that it appears as if it is coming from the OpenVPN server itself and not from the OpenVPN client. This is an easy shortcut to get routing to work, but the disadvantage is that it is no longer possible to distinguish whether such traffic is coming from the OpenVPN server itself, or from one of the connected clients. Redirecting the default gateway A very common use of a VPN is to route all the traffic over a
15:44:35 2014 GLOBAL STATS Max bcast/mcast queue length,0 END The CLIENT LIST shows the list of connected clients, including information about the number of bytes received and bytes sent. The ROUTING TABLE shows the list of OpenVPN internal routes: The subnet 192.168.4.0/24 is routed to client1 due to the iroute statement in the server configuration The IP address 10.200.0.99 is the IP address of client1 which we set explicitly in the CCD file named client1 When the client disconnects,
afterwards the DD-WRT interface should be available again. Your router is now ready to be configured as either an OpenVPN client or an OpenVPN server. Using a home router as a VPN client You can use the following procedure to configure a DD-WRT router as an OpenVPN client: In the DD-WRT web interface, click on the Services tab and then click on VPN. Click on the Enable radio button next to Start OpenVPN Client. Fill in the connection details and enable Advanced Options, as shown in
tun0 10.200.0.2/24 broadcast 10.200.0.255 Initialization Sequence Completed write to TUN/TAP : Invalid argument (code=22) The server log file will list the same WARNING messages, and it will also show decompression warnings: client3/