The server accepts connections only from a single IP address and port The server listens only on one interface and one UDP port For example, when we ping a machine on the client-side LAN from the server, we will see the following: Now our site-to-site tunnel is established.Ĭheck the log files on both the client and server to verify that the connection has been established.Īfter the connection comes up, the machines on the LANs behind both the end points can be reached over the OpenVPN tunnel.
HOW TO USE OPENVPN CODE
Here's the code for the client end: ]# openvpn -config nf The following is for the server end: ]# openvpn -config nf On the client side, create the configuration file: dev tun Group nobody # use "group nogroup" on some distros Here, 192.168.4.5 is the LAN IP address of the OpenVPN client.įrom the server, we can now ping machines on the client LAN. If you look at the keys carefully, you will see that each one of them is mirrored on the client and the server side. On the client side, we will find the same keys but the "Encrypt" and "Decrypt" keys would have been reversed. Using 160 bit message hash 'SHA1' for HMAC authentication Static Encrypt:Ĭipher 'BF-CBC' initialized with 128 bit keyĬIPHER KEY: 80797ddc 547fbdef 79eb353f 2a1f3d1f Note that the output has been reformatted for clarity. If we look through the server-side messages (searching for crypt), we can find the negotiated keys on the server side. The connection will be established with a lot of debugging messages. Then launch the client-side OpenVPN process: C:\>"\Program Files\OpenVPN\bin\openvpn.exe" \ -ifconfig 10.200.0.2 10.200.0.1 \ -dev tun -secret secret.key 1\ -remote openvpnserver \ -verb 7 Launch the server-side (listening) OpenVPN process with an extra option to the -secret parameter and with more verbose logging: ]# openvpn \ -ifconfig 10.200.0.1 10.200.0.2 \ -dev tun -secret secret.key 0 \ -verb 7 Finally, you will learn to manage, secure, and troubleshoot your virtual private networks using OpenVPN 2.4. This book will explore all the advanced features of OpenVPN and even some undocumented options, covering all the common network setups such as point-to-point networks and multi-client TUN-style and TAP-style networks.
HOW TO USE OPENVPN HOW TO
You will also get an understanding of IPv6 support and will get a demonstration of how to establish a connection via IPv64. You will also get to grips with the encryption, authentication, security, extensibility, and certifications features of OpenSSL. You will learn to configure a scalable, load-balanced VPN server farm that can handle thousands of dynamic connections from incoming VPN clients. This book provides you with many different recipes to help you set up, monitor, and troubleshoot an OpenVPN network. OpenVPN provides an extensible VPN framework that has been designed to ease site-specific customization, such as providing the capability to distribute a customized installation package to clients, and supporting alternative authentication methods via OpenVPN’s plugin module interface.