document updated 11 years ago, on Oct 31, 2012

Tunnelling protocols

SOCKS
L2TP
PPTP
IPsec (note: IPsec can be used without encyrption, if you want to use it for just a basic tunnel)

Client-side software that does transparent proxying

Protocols:

TUN/TAP

Client-end software:

OpenVPN [Windows, Linux, OS X, Solaris, OpenBSD, FreeBSD, NetBSD, QNX]
- yes, it can be "merged"† [1]
- Windows installers / GUIs
  - (documentation when running on Windows)
  - openvpn.se — this is the one that's included in the official installer
  - openvpn-gui @ sourceforge — this is the one that WILL be included in the official installer soon
  - OpenVPN Portable
  - OpenVPN Manager
  - more
  - more
- the Windows version uses the Tap-Win32 driver [1] [2] that is authored by OpenVPN
other things that use OpenVPN's Win32 driver
- BadVPN
  - tun2socks can be used to socksify an SSH session [Windows, Un*x]
- tapcfg. Things that use it: [1] [2]
- windows version of QEMU
SOCKS-based
- WideCap [Windows]
  - yes, it can be "merged"† — see the the Network > New Rule screen
  - setup screenshots: [1] [2]
  - yes, it's currently 100% free, though the website makes many contradictory statements
    - [not free?] the license page says that you MUST register the program after the 30 day trial period
    - [yes, free?] the How To Buy screen says "there's no way"
    - [okay, it's totally free] after you install WideCap, the Sponsors screen says "Advertisement is helping keep the WideCap freeware"
- FreeCap [Windows]
  - predacessor to WideCap
  - setup screenshots: [1] [2] [3] [4]
- Sockscap [Windows]
  - much older? Authored by NEC.
  - various places to download it
  - setup screenshots: [1]
- ProxyCap ($30, free trial) [Windows]
- SOCKSchain ($50, free trial) [Windows]
- iptables transparent proxy⇒SOCKS [Linux, OS/X]
  - You can set it up manually. [1] [2] But there are boxed solutions too:
  - redsocks
  - TransSocks
  - sshuttle
- if you don't have admin rights, you can also do the LD_PRELOAD trick
  - Dante's socksify [Linux]
  - ProxyChains [Linux]
  - tsocks [Linux]
OpenSSH's layer-3 tunnel [Un*x, no Windows]
VTUN [Linux, FreeBSD, Solaris]
- Windows is not supported

† I use the term "merged" to mean that both the tunnel as well as the local LAN can be used at the same time, based on rules (eg. netmask rules, routing rules). This is in contrast to some client-side VPN programs, which prevent you from connecting to the local LAN while you're connected to the remote network.

terminology

proxifier — Any utility which makes allows other programs able to use a proxy without being explicitely configured to do so. This is particularly useful for when programs don't have built-in support for SOCKS proxies.

random / search

READ MORE HERE
note that the "Microsoft Loopback Adapter" can be used, along with port-forwarding, to port-forward to a local IP that's completely made-up [1] [2] [3]
- note: you can add ONLY ONE loopback adapter per system!
note that WinPCap is capable of doing bridging (via pcap_inject()/pcap_sendpacket())