Why bypass the guard

When I was in school, most people should have experienced the situation that the guard would not let you into the school. Why would it be like this? Because you were recognized by the security guard, you did not wear a uniform with the school card and still want to enter the school (that is, you can not prove that you are a student of the school), the door is not. When you encounter a closed door, you should actively look for a window. Like sneaking in through the little door. In short, you want to go somewhere you’re not qualified for and be recognized.

Everyone in this day and age knows that clicking on the Internet will probably give you a 404 (we’re only talking about banned 404). This time if you want to through the normal way (the same network environment, the same operation) is unable to open the web page you want to see. So you have to get around it, or create a diversion.

How did the doorman know to stop you

Because you’re not wearing a uniform and you want to go to school.

In the browser, if you want to go to a certain site, you have to enter the domain name of the url. This is very easy. The mechanism will compare the address of the place you want to go to with the list of addresses that need to be banned to know whether to block you.

How do I get past the doorman

Wear school uniforms and climb walls.

There is a saying that one foot tall devil is one foot tall, although you have the list, that I change the address is not finished. (The technical knowledge involved here is that the website we visit has two addresses, one is a domain name address, the other is an IP address, the domain name address corresponds to the same IP address) Add an address to the list, the banned address just need to change the domain name to change the IP address. But this method is generally used for small sites (such as porn sites), as long as the address change is fast enough, you can not seal me :). But in fact, there are corresponding methods to seal. Big sites, like Google, can’t change their IP addresses just because you can’t get to them. There’s a way to do it. You’re going out to school and you tell the doorman I’m going to buy a pen from a stationery store down the street, but you’re sneaking into an Internet cafe across the street.

Some lockdown related concepts

For example, some companies forbid employees to use QQ or wechat or insert USB flash drives in the office, which is a form of making the company’s internal information independent of the Internet. We can’t access Google either.

The main techniques and forms of blockade

  • Ports and IP addresses are blocked
    • Because the default port to access the site is 80, access is blocked;
    • IP blocking is the list mentioned above. Access to this IP address is blocked if it is detected.
  • DNS domain name hijacking
    • Before sending a request for a domain name, you need to query the corresponding IP address through the DNS service.
    • The ** mechanism can return the wrong IP address when you query.
  • Packet filtering by keyword
    • After knowing the IP address, the system initiates an HTTP request and intercepts the request if it contains the blocking keyword.
  • Traffic monitoring
    • Check the direction and frequency of traffic

countermeasures

  • Proxy server (forwarding data with foreign host)
    • Take a broader approach and use a normal server to relay requests
  • Data encryption (with encryption software)
    • The ** mechanism cannot detect the requested content
  • Use a secure VPN connection
    • Establish dedicated network channels on the requester and receiver

Some principles of XX technology

  • You can change hosts to directly access the corresponding IP address, bypassing the procedure of querying IP addresses based on domain names. However, the IP address may be blocked.

  • VPN, encrypts and forwards requests.

A light ladder over the wall

In the communication group to see a lot of people ask how to XX, but get their own bai. Make technical friends may be quick to search, small white may meng forced. Putting yourself? What to build, how to build, what to build has become a problem. After a few searches, you get a full mess, and you may just give up. I also feel that it is really a tedious thing.

Luckily, you found an easy way to sign up at thatseed and pay for it. Just one piece will go a long way. After downloading tools to help us XX, we need to configure after installation. The configuration is extremely simple, choose which node you want to use. Right click on the tool server → scan the two-dimensional code on the screen. Configuration complete, try to access Google.

Perfect ؏؏☝ᖗ乛◡乛ᖘ☝؏؏

If there are mistakes, please correct them.