This article mainly introduces the overview of the network protocol: physical layer, link layer, network layer, transport layer, and application layer. This article uses the mailman and post office in life to help understand complex network protocols. It is easy to understand and humorous. Is a rare good article, need friends can refer to The transmission of signals always meets a certain protocol.For example, the Wolf is placed on the Great Wall because people have pre-set the physical signal of Wolf Smoke to represent the abstract signal of “enemies invasion”.Such a "wolf smoke = enemy invasion" is a simple agreement.The protocol can be more complex, such as Morse Code, using a combination of short and long signals to represent different English alphabets.For example, SOS (***---***, * for short signals, - for long signals).This "***= S, ---=O" is the agreement of the Morse code.However, one more level, people will know SOS is for help information, because we have "SOS = help" agreement exists in the mind.So "***---***=SOS=help" is a layered communication system consisting of two protocols. Telegraph using Morse Code Communication between computers also follows different levels of protocols to achieve computer communications. Physical layer The so-called physical layer refers to
In general, remote desktops are generally used for remote management of server management and general computers in LANs.In fact, the remote desktop is not only limited to the LAN, as long as the IP is reachable, our computers can all be remote desktop connections on other computers.Due to insufficient IPV4 addresses, IPv4 over NAT does not allow us to find any host on the Internet, but endless IPv6 addresses this problem perfectly.Due to the fact that some schools, such as extreme guests, connect to the campus network, Ruijie must use account authentication to access IPv4 computers in the LAN.Therefore, in the school computer room remote desktop desktop computer, often encountered Ruijie did not log in and can not connect to the dormitory computer problems.However, if you visit through IPV6 do not have to consider this issue, of course, I have no way to plug your network cable. There is no difference between IPv6 and remote desktop and IPv4. How to use remote desktop to control your own computer is described in my previous article: The first step, get the local IPV6 address and domain name resolution The advantage of IPV6 is that the address is long (128-bit binary), so the
Because Ruijie is not enough, the extreme guests are bumping around looking for free internet access. Some time ago, they found that they could use the 6 free internet access methods immediately. They found that after completing Ruijie and then they would not be able to access the intranet IP after 6 and they would not be able to access the school. The FTP, the remote desktop in the school lab could not access the dormitory computer, and our visit to the campus network and free internet access seemed to be an incomparable thing for both the fish and the paw.The guests here share with you how to use the command line to access the intranet and extranet at the same time. I. Problem Analysis We know that a gateway is an IP address that connects two different networks or one network to other networks.Pole users enter "ipconfig" at the command line to get the local IP information as follows: As apparent from the "Local Connection 3" immediately 6 and the "local connection" campus network is not on a network segment.Then I enter the "route print" command line to get the local routing information: Command indicator for configuring gateway and
Since the opening of Wang Boyuan’s blog, the author has been harassed by malicious registration and robot advertisement comments on more than one occasion.Yesterday, I received an ad comment and found that the user IP that the review user fills in is the same as the IP of the user. Undoubtedly, this shows that this is a comment of the network robot brush.So I had an idea to directly block this IP to access my blog.The following describes my solution. How the virtual host masks a specified IP or network segment In general, virtual hosts do not provide the ability to shield IP access in host management. Of course, it is much more convenient if you have them.In fact, even if the virtual host provider does not provide the ability to block specified IP access, we can implement it very simply. The method is very simple: Add the IP blocking field in the htaccess file.(The writing of the htaccess file and the role of an article in front of me is quite detailed explanation, if you have a strong interest in anti-theft chain, 301 redirects, custom error pages, etc., you may wish to look at this article: 21 Very useful
Today, an anonymous friend posted a comment on my blog and asked me not to check his IP address, but I did count on the comment management that I had on the background to find out his IP, although I know that the website is generally available. Get the user's IP address.However, this investigation surprised me. So Baidu took a look at this IP, inquiries to the detailed physical address of the IP at http://ip.911cha.com/, its accuracy surprised me. As a friend's privacy, the IP in the first picture is hidden behind him. For the "hidden IP" approach, we can use Baidu. So, when we express our opinions on major websites, will you reflect on: Space, can you really hide?