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@klzgrad
klzgrad / Naive-VPN.md
Created November 17, 2014 00:43
朴素VPN:一个纯内核级静态隧道

朴素VPN:一个纯内核级静态隧道

由于路由管控系统的建立,实时动态黑洞路由已成为最有效的封锁手段,TCP连接重置和DNS污染成为次要手段,利用漏洞的穿墙方法已不再具有普遍意义。对此应对方法是多样化协议的VPN来抵抗识别。这里介绍一种太简单、有时很朴素的“穷人VPN”。

朴素VPN只需要一次内核配置(Linux内核),即可永久稳定运行,不需要任何用户态守护进程。所有流量转换和加密全部由内核完成,原生性能,开销几乎没有。静态配置,避免动态握手和参数协商产生指纹特征导致被识别。并且支持NAT,移动的内网用户可以使用此方法。支持广泛,基于L2TPv3标准,Linux内核3.2+都有支持,其他操作系统原则上也能支持。但有两个局限:需要root权限;一个隧道只支持一个用户。

朴素VPN利用UDP封装的静态L2TP隧道实现VPN,内核XFRM实现静态IPsec。实际上IP-in-IP隧道即可实现VPN,但是这种协议无法穿越NAT,因此必须利用UDP封装。内核3.18将支持Foo-over-UDP,在UDP里面直接封装IP,与静态的L2TP-over-UDP很类似。

创建一个朴素VPN

@gmaclennan
gmaclennan / guyana-volunteer-wifi.md
Last active July 4, 2018 18:43
Long-distance solar-powered wifi in the forests and savannahs of Guyana

Overview

Digital Democracy is looking for a volunteer to help pilot long-distance solar-powered wifi antennaes in indigenous communities in Guyana.

Background

Digital Democracy is working with the Wapichan people in the South Rupununi in Guyana to support them in efforts to secure their ancestral territory and increase their autonomy and self-determination. The Wapichan live in 17 villages and 7 smaller "satellites" in a large semi-natural savannah ecosystem surrounded by tropical forest. Communication between villages and with the outside world is difficult due to limited or no cellphone or internet access. We want to help the Wapichan improve their means of communicating with the rest of the world and communicating and coordinating between villages.

Location