Simpleproxy

Simpleproxy has several options, you can do man simpleproxy to read them all.

However, if you just want to forward all traffic that comes to this server port 1111 to the address and port 2.3.4.5:6666, then do the following:

simpleproxy -L 1111 -R 2.3.4.5:6666

You can also save the configuration to file, load the file upon startup, dump the traffic to a file, redoirect output to the system log, etc. Read the

man simpleproxy