Socks5
SOCKS5 is a proxy protocol that acts as an intermediary between front-end machines and server machines that communicate with TCP/IP protocol, making front-end machines in the intranet accessible to servers on the Internet or to making communication more secure. The SOCKS5 server simulates a front-end behavior by forwarding the front-end request to the real target server. Here, the front-end and SOCKS5 also communicate through the TCP/IP protocol, the front-end to send the original to the real server to the SOCKS5 server, and then SOCKS5 the server to forward the request to the real server.
If your machine has a legitimate Internet IP address, or if you use a modem on your machine to dial the Internet and you are free to communicate with any host on the Internet, you usually don't have to care about the SOCKS5 protocol. The SOCKS5 protocol is useful for machines in the internal network that need to be accessed externally through certain machines in the network that can connect to the external Internet. The SOCKS5 server does not change the request packet itself in the process of sending a communication request to a real server. When the SOCKS5 server receives a response from a true server, it is forwarded to the front end as is. Therefore, the SOCKS5 protocol is a proxy protocol, which can adapt to all kinds of TCP/IP based application layer protocols and is almost omnipotent. Although it does not understand the internal structure of the data that it forwards, it can faithfully forward the communication packets and complete the functions that the protocol would have done.
Unlike the SOCKS5 protocol, HTTP proxies are carried out through HTTP protocol, the HTTP proxy Server software understands the internal structure of the packet, and during the forwarding process, the communication is modified and converted to some kind of program. Unlike the HTTP proxy protocol, SOCKS5 is actually an agent protocol for a transport layer. We can imagine that if each specific application layer protocol is designed to represent the corresponding proxy protocol, a particular proxy server will not be able to support a number of emerging protocols anyway. Therefore, it can be said that the emergence of SOCKS5 to alleviate a variety of specific agreements need to design a special agency agreement difficult situation. However, not always use the TCP/IP protocol based application protocol software, can unconditionally through the SOCKS5 server for communication, but also requires the front-end software itself has SOCKS5 interface, in order to use SOCKS5 Proxy server.
Installation configuration
1. Installation of SOCKS 5
1.1 Installation Dependent Development Library
# yum Install pam-devel openldap-devel openssl-devel
1.2 Installation Socks 5
# wget Http://downloads.sourceforge.net/project/ss5/ss5/3.8.9-8/ss5-3.8.9-8.tar.gz?r=&ts=1396802581&use_ Mirror=cznic
# TAR-XZVF Ss5-3.8.9-8.tar.gz
# CD ss5-3.8.9
#./configure
# make
# make Install
2. Socks 5 Configuration
2.1 Modifying the configuration file
# vim/etc/opt/ss5/ss5.conf
Auth 0.0.0.0/0–-
To
Auth 0.0.0.0/0–u
permit–0.0.0.0/0–0.0.0.0/0––––-
Change into
Permit U 0.0.0.0/0–0.0.0.0/0––––-
3. Add Socket 5 User
# CAT/ETC/OPT/SS5/SS5.PASSWD
# #用户 Password
Ttlsa 123456
4. Start Socket 5
# SH/ETC/RC.D/INIT.D/SS5 Start
Doneting ss5 ...
The default SS5 file does not execute permissions, if you feel the use of sh to start trouble, then the following methods:
# chmod U+X/ETC/RC.D/INIT.D/SS5
# chkconfig--add ss5/optional
# chkconfig SS5 on//optional
# service SS5 Start
5. See if it starts
# NETSTAT-LNTP | grep SS5
TCP 0 0 0.0.0.0:1080 0.0.0.0:* LISTEN 14262/ss5
Default Port 1080
6. Test SOCKS5
Install Proxifier, by default all requests go socks5. Open Baidu, input IP, you can see the following result is our operational Life Time (ttlsa.com) IP address
7. Common Mistakes
7.1 Missing Pam
Configure:error: * * * Some of the The headers weren ' t found * * *
# yum-y Install Pam-devel