Restrict access to a specified website using the access control list (1)

Recently, some colleagues often make "small reports", complain that the network speed is getting slower and slower, and the leaders also "share the same feeling". This problem must be solved. Otherwise, when "the leaders are angry, it must be "very serious consequences.

First, Sniffer sniffed and analyzed the traffic, and then "mingcha unannounced visits". Finally, it was concluded that recently, a group of colleagues often did not perform business properly. They had no choice but to watch videos online on some podcast websites, when a large amount of bandwidth is occupied, other colleagues naturally feel that the network speed is slow. Originally, we wanted to directly disable the streaming media service. However, considering that leaders sometimes need to use online video applications, we have to leave this method alone. The final solution is to block all mainstream Chinese podcast sites. If they do not go to the podcast site, they naturally cannot watch videos online. You can do what you want. When implementing the ACL (Access Control List, Access Control List), you can use the Access Control List, you can easily restrict Intranet employees to access certain specified websites.

1. Obtain the website IP Address

The best way to control the access control list is to directly control the IP address. Therefore, to restrict access to a specified website, you must know the IP address of the website. The method for obtaining the website IP address is also very simple. You can Ping it to return the IP address of the website (1 ).

Figure 1

However, the IP addresses obtained using Ping are often not "reliable". The reason is that many large portal websites are using cluster and network load balancing technologies, that is to say, the whole website is not a server, but composed of multiple servers and multiple IP addresses, which can ensure the stability and access speed of the website. In this case, Ping is often used to obtain only one IP address, while other IP addresses become "the fish of the Internet". Thus, blocking an IP address obviously does not work, so it is necessary to restrict employees to access a website, all IP addresses of the website must be blocked.

Go to the "command prompt" window and run the "nslookup URL" command to obtain all the IP addresses of the website. For example, obtain all the IP addresses of the Netease main site (2 ).

Figure 2