Network device hard core technology insider router Chapter 22

Let's pull the meeting back to the news broadcast of that year ——

“ I'm looking up information online , Pop up an advertisement , very pornographic, very violent , I turned it off immediately .”

I believe that pop-up advertisements are very yellow and violent , It's not new to everyone . however , If you simply think that those who put these advertisements are website operators , that , You are silly and naive .

Let's go over it again , From typing the URL to page rendering ——

1. Browser call Windows( It can also be Linux) Protocol stack of , The operating system is going to DNS Initiate domain name resolution request ;
2. DNS Return the domain name resolved IP Address , Browser to destination IP launch TCP/HTTP Connection request ;
3. Server handle HTTP The packet returns to the client ;

In this part , Routers act as packets “ A setter ”, It can easily monitor and rewrite the contents of data packets . that , If the router passes DPI technology , Identified HTTP, And in HTTP Insert advertisements into the data package ？

Some students who have studied the previous content may ask ,ISP Backbone network 、 Most routers of metropolitan core and metropolitan edge networks use NP Realization , and NP Its characteristics make it difficult to HTTP Such an upper layer agreement , Insert to MB The advertising content of the plan . that , Who is inserting these advertisements ？

Focus our attention on the home broadband router ——

stay 2012-2014 During the year , A business model for home broadband routers is , Free equipment , Make money by inserting advertisements into web pages .

Its implementation principle is also very simple —— Found to be HTTP Data flow , Insert an advertisement in the header of the web page . When the network is idle, download the advertising content to be inserted locally .

Because the home broadband router can obtain all users' online behaviors , Search behavior , therefore , Users are transparent about this business model , Device providers can infer users' purchase preferences by analyzing users' online behavior , And targeted advertising .

therefore , In these years , We found that , Most portals , A small lock is hung on the address bar ——

This lock represents HTTPS.HTTPS Yes, it will HTTP stay SSL/TLS Encrypted Socket It's transmitted in , such , Third parties cannot listen to packets , And insert the content you want to insert .

this , Also means that , Monitor in your home router HTTP The business model of inserting advertisements has come to an end .

Problems left over from the previous issue ：

You know the most classic reconfigurable FPGA What kind of router is it ？

answer ： yes H3C Of SR66-X series .