The method of using proxy to set up Internet in Linux __linux

In Linux with the agent online because the campus network to visit foreign websites to collect fees, so the first two days to find a free IP Internet, set as follows:
Because the school uses the static IP, therefore first sets up the system static IP
1. Set the system IP address and Mac (use terminal root)
Ifconfig eth0 aaa:bbb:ccc:ddd
Ifconfig eth0 ether Aa:bb:cc:dd:ee:ff
2. Set Proxy service IP
Set the proxy server IP and port number in the browser, such as setting steps in Mozilla Firefox: Edit-> Preferences-> Advanced-> network-> connection settings-> manually set up the proxy
Enter proxy IP address and port number