shadowsocks-libev(8) a lightweight and secure socks5 proxy


    [-s server_host]     [-p server_port]
    [-l local_port]      [-k password]
    [-m encrypt_method]  [-f pid_file]
    [-t timeout]         [-c config_file]


Shadowsocks-libev is a lightweight and secure socks5 proxy. It is a port of the original shadowsocks created by clowwindy. Shadowsocks-libev is written in pure C and takes advantage of libev to achieve both high performance and low resource consumption.

Shadowsocks-libev consists of five components. One is ss-server(1) that runs on a remote server to provide secured tunnel service. ss-local(1) and ss-redir(1) are clients on your local machines to proxy TCP traffic. ss-tunnel(1) is a tool for local port forwarding.

While ss-local(1) works as a standard socks5 proxy, ss-redir(1) works as a transparent proxy and requires netfilter's NAT module. For more information, check out the example section.

ss-manager(1) is a controller for multi-user management and traffic statistics, using UNIX domain socket to talk with ss-server(1). Also, it provides a UNIX domain socket or IP based API for other software. About the details of this API, please refer to the protocol section.


-s server_host
Set the server's hostname or IP.
-p server_port
Set the server's port number.

Not available in manager mode.

-l local_port
Set the local port number.

Not available in server nor manager mode.

-k password
Set the password. The server and the client should use the same password.
-m encrypt_method
Set the cipher.

Shadowsocks-libev accepts 18 different ciphers: table, rc4, rc4-md5, aes-128-cfb, aes-192-cfb, aes-256-cfb, bf-cfb, camellia-128-cfb, camellia-192-cfb, camellia-256-cfb, cast5-cfb, des-cfb, idea-cfb, rc2-cfb, seed-cfb, salsa20, chacha20 and chacha20-ietf. The default cipher is table.

If built with PolarSSL or custom OpenSSL libraries, some of these ciphers may not work.

-a user_name
Run as a specific user.
-f pid_file
Start shadowsocks as a daemon with specific pid file.
-t timeout
Set the socket timeout in seconds. The default value is 60.
-c config_file
Use a configuration file.
-n number
Specify max number of open files.

Not available in manager mode.

Only available on Linux.

-i interface
Send traffic through specific network interface.

For example, there are three interfaces in your device, which is lo (, eth0 ( and eth1 ( Meanwhile, you configure shadowsocks-libev to listen on and bind to eth1. That results the traffic go out through eth1, but not lo nor eth0. This option is useful to control traffic in multi-interface environment.

Not available in redir mode.

-b local_address
Specify local address to bind.

Not available in server nor manager mode.

Enable UDP relay.

TPROXY is required in redir mode. You may need root permission.

Enable UDP relay and disable TCP relay.

Not available in local mode.

Enable onetime authentication.
Enable white list mode (when ACL enabled).

Only available in server mode.

-L addr:port
Specify destination server address and port for local port forwarding.

Only available in tunnel mode.

-d addr
Setup name servers for internal DNS resolver (libudns). The default server is fetched from /etc/resolv.conf.

Only available in server and manager mode.

Enable TCP fast open.

Not available in redir nor tunnel mode, with Linux kernel > 3.7.0.

--acl acl_config
Enable ACL (Access Control List) and specify config file.

Not available in redir nor tunnel mode.

--manager-address path_to_unix_domain
Specify UNIX domain socket address.

Only available in server and manager mode.

--executable path_to_server_executable
Specify the executable path of ss-server.

Only available in manager mode.

Enable verbose mode.
-h, --help
Print help message.


ss-redir requires netfilter's NAT function. Here is an example:

    # Create new chain
    [email protected]:~# iptables -t nat -N SHADOWSOCKS
    [email protected]:~# iptables -t mangle -N SHADOWSOCKS
    # Ignore your shadowsocks server's addresses
    # It's very IMPORTANT, just be careful.
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    # Ignore LANs and any other addresses you'd like to bypass the proxy
    # See Wikipedia and RFC5735 for full list of reserved networks.
    # See ashi009/bestroutetb for a highly optimized CHN route list.
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -d -j RETURN
    # Anything else should be redirected to shadowsocks's local port
    [email protected]:~# iptables -t nat -A SHADOWSOCKS -p tcp -j REDIRECT --to-ports 12345
    # Add any UDP rules
    [email protected]:~# ip rule add fwmark 0x01/0x01 table 100
    [email protected]:~# ip route add local dev lo table 100
    [email protected]:~# iptables -t mangle -A SHADOWSOCKS -p udp --dport 53 -j TPROXY --on-port 12345 --tproxy-mark 0x01/0x01
    # Apply the rules
    [email protected]:~# iptables -t nat -A PREROUTING -p tcp -j SHADOWSOCKS
    [email protected]:~# iptables -t mangle -A PREROUTING -j SHADOWSOCKS
    # Start the shadowsocks-redir
    [email protected]:~# ss-redir -u -c /etc/config/shadowsocks.json -f /var/run/


ss-manager(1) provides several APIs through UDP protocol:

Send UDP commands in the following format to the manager-address provided to ss-manager(1).

    command: [JSON data]

To add a port:

    add: {"server_port": 8001, "password":"7cd308cc059"}

To remove a port:

    remove: {"server_port": 8001}

To receive a pong:


Then ss-manager(1) will send back the traffic statistics:

    stat: {"8001":11370}


shadowsocks was created by clowwindy <[email protected]> and shadowsocks-libev was maintained by Max Lv <[email protected]> and Linus Yang <[email protected]>.

This manual page was written by Max Lv <[email protected]>.

The manual pages were rearranged by hosiet <[email protected]>.