13 bypass GFW

13.1 V2Ray

The next generation, to be continued.

13.2 shadowsocks

13.2.1 installing

• sudo apt -y install python-pip python-m2crypto ¹⁶
• sudo -H pip install shadowsocks
• Chrome extension SwitchyOmega.

13.2.2 configuration file

sudo mkdir /etc/shadowsocks

sudo vim /etc/shadowsocks/ipv4.json

{
    "server":      "my ipv4",
    "server_port": 21,
    "local_port":  1084,
    "password":    "my password",
    "fast_open":   true
}

13.2.3 managing by systemd

sudo vim /etc/systemd/system/shadowsocks-ipv4.service

[Unit]
Description=Shadowsocks client ipv4

[Service]
ExecStart=/usr/local/bin/ssserver -c /etc/shadowsocks/ipv4.json

[Install]
WantedBy=multi-user.target

• for client, use sslocal instead of sserver, and add User=nobody
• for CentOS, use /usr/bin/ instead of /usr/local/bin/

13.2.4 details

Refer to https://github.com/shadowsocks/shadowsocks/wiki/Configuration-via-Config-File .

1. server_port

   此外，选择合适的端口也能优化梯子的速度，广大SS用户的实践经验表明，检查站（GFW）存在一种机制来降低自身的运算压力，即常用的协议端口（如http，smtp，ssh，https，ftp等）的检查较少，所以建议SS绑定这些常用的端口（如：21，22，25，80，443），速度也会有显著提升。

   — https://github.com/iMeiji/shadowsocks_install/wiki/shadowsocks-optimize#3-%E7%BD%91%E7%BB%9C%E5%B1%82%E9%9D%A2

   I use 80 for ipv4, since 80 < 443 and 4 < 6.

2. local_port

   It’s ignored by ssserver, but I add it so that I can just directly copy the configuration files from local to server without any modifications.

3. method

   They are so many different opinions. I finally gave up and chose to just trust the developers ¹⁷.

4. fast_open

   sudo vim /etc/sysctl.d/local.conf

   # turn on TCP Fast Open on both client and server side
   net.ipv4.tcp_fastopen = 3

   sudo sysctl --system

5. workers

   For example, if you set to 4, you will get 4 child process.

   对于python来说，是没有正真意义上的多线程的，因此通过worker实现多进程，提高性能，通常来说，一个cpu核心给4个worker应该差不多

   — https://github.com/shadowsocks/shadowsocks/issues/900

13.2.5 optimization

• kernel optimization ¹⁸
• allow more open file descriptors

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16. According to https://github.com/shadowsocks/shadowsocks/wiki/Encryption, installing M2Crypto will make encryption a little faster.↩︎

17. They will choose the best method for me, I even don’t bother to set it.↩︎

18. That method trades off RAM for speed. Actually, there are only a few free memory left on my VPS, so it can hardly perform anything else after turning on this feature.↩︎