Transferred from: http://www.cnblogs.com/airsong23/p/3893094.html
Conditions of adaptation:
Sometimes, our machine host-a can only access the Internet through Proxy server host-b, and the machine connected to US host-c also needs to access the Internet, but Host-c does not have direct access to host-a, At this point can be host-a as a bridge (level two proxy server), let host-c access to the Internet, the following is the open source 3proxy as a two-level proxy server Configuration sample
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# 3proxy 0.6.1
# 3proxy.cfg Two-level proxy configuration sample
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# Let the log output from the stdout (standard output) that is the command line interface.
Log
# The new ACL (Access control list) starts.
Flush
# give DNS resolution to the parent agent to complete.
Fakeresolve
# DNS Cache
Nscache 65536
# Bind the IP address of the "intranet" interface, and other machines connect to the Internet via this IP address.
#internal 172.17.23.135
Internal 192.168.21.177
# Bind the IP address of the "Extranet" interface, which is directly connected to the superior agent
External 192.168.21.177
# Select the authentication mechanism for IPONLY (based on IP control only).
Auth Iponly
# Allow all connections
Allow *
# Specify the parameters of the parent proxy server such as parent 8080 HTTP 192.168.2.1
# The first parameter (1000) is used to set the "weight" of each specific proxy server in a combination of multiple proxy servers to achieve controllable load balancing, set to 1000, which means that only one parent agent
# "HTTP" indicates the proxy type. "192.168.2.1" is the IP address of the parent agent. "8080" is an interface.
Parent 192.168.2.1 http 8080
# Limit the maximum number of simultaneous connections to 100
Maxconn 100
# open proxy, port 8080
Proxy-a-p8080
# Limit Maximum bandwidth 800Kbps
Bandlimin 819200 *
# End of configuration
End
[Transfer]3proxy Two-level agent configuration Example