Free vpn software for linux

VPN HOWTO is a document that describes how to set up a Virtual Private Network with Linux.
Main features:
- Section 1: Introduction
- Section 2: Theory
- Basic VPN theory. What is a VPN, and how does it work. Read this if you are entirely new to VPN.
- Section 3: Server
- This section describes how a VPN server is set up.
- Section 4: Client
- This section describes how a VPN client is set up.
- Section 5: Implementation
- A step by step implementation of a sample VPN setup.
- Section 6: Addenda
- Other bits and pieces of info that you might find helpful.

vpn-shaper provides a dynamic traffic shaper for vpn, poptop, and similar programs, using iproute2.

vpn-shaper is a dynamic traffic shaper for openvpn, poptop, and similar programs, using iproute2. It allows shaping of traffic between many users conected to one server, and it supports different prioritiy schemes for different users and different types of traffic.

Trafic shaping uses the HTB qdisc. Prioritization uses l7-filter and ipp2p and some of the patch-o-matic extensions.

Classification of trafic in HTB classes is done by using the IPMARC patch-o-matic extension.

OpenVPN is a full-featured SSL VPN solution which can accomodate a wide range of configurations, including remote access, site-to-site VPNs, WiFi security, and enterprise-scale remote access solutions with load balancing, failover, and fine-grained access-controls (articles) (examples) (security overview) (non-english languages).
OpenVPN implements OSI layer 2 or 3 secure network extension using the industry standard SSL/TLS protocol, supports flexible client authentication methods based on certificates, smart cards, and/or 2-factor authentication, and allows user or group-specific access control policies using firewall rules applied to the VPN virtual interface. OpenVPN is not a web proxy and does not operate through a web browser.
For a good conceptual introduction to OpenVPN, see the program notes for James Yonans talk at Linux Fest Northwest 2004 -- Understanding the User-Space VPN: History, Conceptual Foundations, and Practical Usage. See also OpenVPN and the SSL VPN Revolution by Charlie Hosner.
OpenVPN is an Open Source project and is licensed under the GPL. Commercial licenses are also available for firms who would like to redistribute OpenVPN with their own proprietary applications. Contact info@openvpn.net for more information.
Main features:
- tunnel any IP subnetwork or virtual ethernet adapter over a single UDP or TCP port,
- configure a scalable, load-balanced VPN server farm using one or more machines which can handle thousands of dynamic connections from incoming VPN clients,
- use all of the encryption, authentication, and certification features of the OpenSSL library to protect your private network traffic as it transits the internet,
- use any cipher, key size, or HMAC digest (for datagram integrity checking) supported by the OpenSSL library,
- choose between static-key based conventional encryption or certificate-based public key encryption,
- use static, pre-shared keys or TLS-based dynamic key exchange,
- use real-time adaptive link compression and traffic-shaping to manage link bandwidth utilization,
- tunnel networks whose public endpoints are dynamic such as DHCP or dial-in clients,
- tunnel networks through connection-oriented stateful firewalls without having to use explicit firewall rules,
- tunnel networks over NAT,
- create secure ethernet bridges using virtual tap devices, and
- control OpenVPN using a GUI on Windows or Mac OS X.

Viperin-Z is a taskbar applet to manage virtual private network connections on the Sharp Zaurus family of handheld computers.
As a front-end to vpnc, the free Cisco VPN concentrator client, this application can set up various VPN configurations, connect to a selected one and monitor connection status.
Enhancements:
- Create session log in /var/log/viperinz.log
- Updated to work with vpnc 0.3.3
- Fix package removal

uvlan is a project consisting of a User-space Virtual Local Area Network.
In other words, uvlan peers act as nodes on a network switch. Ethernet traffic is routed between peers intelligently. This allows for multiple networks to share resources and even IP address space.
Some may call it a VPN (Virtual Private Network) application, but its much more powerful: it is peer-to-peer, is much simpler, and operates at layer 2 (ethernet). VPNs generally operate at layer-3 (IP), and layer 2 applications like gaming cant be supported with layer 3 tunneling.
Differences with traditional VPN technology:
- It is peer-to-peer
- It doesnt require licensing
- It is much simpler
- It operates at Layer-2 (Ethernet), VPNs generally operate at Layer-3 (IP) Layer-2 applications like gaming cant be supported with Layer-3 tunneling.

Pyroman is a flexible and fast firewall tool.
Main features:
The good:
- Really fast compared to sh+awk based solutions due to using iptables-restore
- Rollback to previous firewall on error to minimize risk of use
- Detailed error reporting to help configuring
- Easy syntax to add hosts, nats
- Designed for complex networks
- Written in easy to read python code
- Extensively documented (Python docstrings)
- You can add custom iptables rules when needed
- Lots of verification checks done before execution
- Designed to use the same configuration files on multiple hosts (e.g. failover firewalls or the destination host itself; it will detect if you are talking about a local or a remote host
The bad:
- Not designed for single-host workstation setups
- Doesnt completely hide iptables complexity from the admin (good or bad?)
- Only iptables, no TC/Shaping, no IPsec, proxy arp setup, VPN, ifconfig (I use other tools for that, e.g. heartbeat)
To tease you a little more into testing, heres an example host configuration: ("dmz" is an interface alias - where the web server is connected to -, as are "INT", "DMZ" and "ANY" for clients on these interfaces)
A really simple webserver configuration.
These examples are just boring...
But without NAT they would be even more boring.
# web server
add_host(
name="web",
ip="10.100.1.2",
iface="dmz"
)
# offering, well, web service.
allow(
client="ANY DMZ INT",
server="web",
service="www ssh ping"
)
# internal hosts may access FTP, too
allow(
client="INT",
server="web",
service="ftp"
)
# setup NAT
add_nat(
client="ANY INT",
server="web",
ip="12.34.56.80"
)
(Yes, this is a python script. No, you probably wont care to write your configuration in a programming language, will you?)
Enhancements:
- New in this version: iptables and kernel version checks (required for the new extended examples bittorrent filter) and some minor code cleanups and refactoring.