Method for router to check the port opened by this machine 1. Check the open ports of this machine.
Use netstat -a? N command view! There is some English in the state. Let me briefly talk about what these English words specifically stand for.
Listening: Listening for connection requests from remote TCP ports.
SYN-SENT: Wait for the matching connection request after sending the connection request again.
SYN-RECEIVED: After receiving and sending another connection request, wait for the other party to confirm the connection request.
ESTABLISHED: indicates an open connection.
FIN-WAIT- 1: Wait for the confirmation of remote TCP connection interrupt request or previous connection interrupt request.
FIN-WAIT-2: Wait for the connection interrupt request from remote TCP.
CLOSE-WAIT: Wait for the local user's connection interruption request.
Close: Wait for remote TCP to confirm that the connection is disconnected.
LAST-ACK: Wait for the confirmation of the original connection interruption request sent to remote TCP.
TIME-WAIT: Wait enough time to ensure that the remote TCP receives the confirmation of the connection interruption request.
Off: No connection status.
Second, get the host name of an IP address.
Use ping -a ip command to view! The English before "『ip』" after ping in the first line is the host name of the other party! Similarly, you can also get the ip of the other party by ping machine_name.
The way to get the ip address of a website is to ping www. ***.com. For example, if you want to know the ip of Laiwu information on the Internet, just ping laiwucom.cn to find it.
By the way: if you come back: reply from *. *.*: TTL expires during transmission, hehe, what does TTL (life cycle) mean when it expires during transmission?
Let me explain! There are two reasons for this problem.
1)TTL value is too small! The TTL value is less than the number of routers passing between you and another host.
2) There are too many routers, and the number of routers passing through is greater than TTL value! Hehe, in fact, these two points mean the same thing! It's just a different story!
3) How to check the ip address of this machine? Just check it with ipconfig! You can also enter winipcfg in the start menu of Windows, and you can also see that if you add a parameter /all after your own ipicponfig command, you can get more detailed information, such as DNS, gateway, etc.
4) When using the net command again, I encountered some error codes. How to view the corresponding error message?
Just use the command nethelpmsgerror _ code to view it. For example, if the error code is: 88, the view command is: net helpmsg 88. Below is the Chinese display of this error code!
5) Use telnet to connect to another host and want to get some system information. What command should I use?
Set command can complete the task of collecting the information you need well! Method: directly enter set under cmd (after set (telnet to the other host, it is also possible to set(set directly ~ then you can get more information about NNNNN). Here, computer name: Needless to say? Host name! OS=Windows_NT: Type of operating system ~ Path = C: \ Perl \ bin \: (Perl interpreter location! ) systemDrive=c: the drive letter of the operating system! USERNAME=coldcrysky Who is currently logged in to use this machine?
(6) What is the command to track the router?
Tracert format: tracert ip will list all passing routers! If these routers are exposed outside the firewall, they can also see the IP of the route. Here comes another question: Why put the route behind the firewall?
There are two main reasons.
1) Protect the router! Because now more and more attacks and intrusions have begun to target the router ~ If the route is directly exposed, hehe, it is very dangerous! It's not good to be DoS ~ hehe, so it should be put in the firewall;
2) Reduce the burden on the router! If all the filtering functions are on the router, hehe, the burden on the router is too great! Of course, using pathping can also achieve the same effect! Same format as tracert!
3) Briefly introduce cookie! Cookies, also known as cookies.
Its function: to record some information of visitors. For example, use cookie to record the number of times you log on to this web page and the information you entered when logging on? The most common thing is that when you log in to the forum (email) again, when you often enter the first letter, all the user names that have logged in to the forum (email) on your computer will often be displayed below, right? Hehe, this is the role of cookies!
You can see a lot of notepad documents in the administrator's cookies directory, right? These are cookie. Although they are encrypted, you can still see some sensitive information when you look closely! In addition, there is now a special software to view cookie! Using these softwares, your privacy will not be guaranteed ~ So, how to clear cookie? Under normal circumstances, you can see a button to delete cookies in the general tab of Internet options, and click it to clear it ~
In addition, you should also find the auto-completion button in the content tab of Internet options, and select all four of them! Then click the clear form to clear the password ~ and then go to the partition where the operating system directory is located! Enter the win nt(windows is 98) directory (of course, these are the default directories! If the name is changed during installation, just go to the corresponding directory and find the directory of temporary Internet files (the directory of 2000 is in C: \ documents and settings \ administrator \ local settings \ temporary Internet files) 98. Go directly to the windows directory to find the temporary online file ~, and then open it! See there are many documents in it?
These are the records of the web pages you visited (sometimes you see beautiful FLASH on the website, but you can't save it. What should I do?
As long as you browse the line once, disconnect here to find *. Swf, and then open in turn, I believe you will find the FLASH you need! ), well, digression ~ Go on: These files are all page records of the website, just delete them directly!
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Articles about router ports:
1. How to modify and increase the router port number to increase security?
2. Teach you how to use router port mapping.
3. Schematic diagram of how the D-Link wireless router sets up port mapping.
4.Cisco router control port connection diagram