Although telnet is not safe in plain text transmission, it is always necessary to take time to learn. I do not have a deep understanding. Currently, most of the cases are through SSH (not quite familiar ).
The environment of my experiment is in Windows XP (host) + centos 6.2 Linux (guest. In fact, we can draw a line from the following: in this case, errors may occur, such as remote connection To routers, switches, and servers.
TIPS: in XP, ipconfig is used to view IP addresses and other information, while ifconfig is used in Linux.
XP: ipaddr: 192.168.1.3
Centos: ipaddr: 192.168.1.4
By default,"Connecting to 192.168.1.3... the connection to the host cannot be opened. port 23: Connection Failed.
So Google, Baidu, most of the answer is:
1: "Administrative Tools"-> "services"-> enable the telnet service (or cmd-> Net start telnet to enable the telnet service)
2: "Control Panel"-> "Windows Firewall"-> "exceptions"-> "add Port"-> Telnet TCP 23 and telnet UDP 23
However, after such an operation, the fact is that it does not play a role at all, but still reports an error, cannot open the host connection.
In fact, the above two operations are completely unnecessary on this issue. The problem is that we want to remotely connect to the Linux end.
Now we want to treat Linux as a server, while XP is only a client, so there is no need to configure the XP Telnet service to enable it, and the firewall does not need to be enabled.
However, if you want your XP Server to be remotely accessed, this is necessary. Okay. Now we can solve the problem accordingly.
In Linux, there are two Telnet function packages: telnet-client as the client and telnet-server as the server.
Enter the Telnet localhost in the terminal and the system prompts "command not found". I thought it was because the telnet-client was not installed.
The yum install telnet-Client Command is displayed with the prompt "no package telnet-client available" when I press the technical key skillfully ". Ah, too confident.
You do not need to worry about this issue currently.
Open the terminal in Linux and enter super administrator mode,
1: Check whether the telnet-Server feature package is installed. If the package is installed, Run "rpm-Qa | grep Telnet". If the package is installed, a version number is output. Jump directly to Step 3. Otherwise, switch to step 2.
2: Install the telnet-server package and Yum install telnet-Server
3: Open the service, VI/etc/xinetd. d/telnet, find disable = Yes, and change Yes to no, ESC, and WQ to save. You can also use chkconfig telnet on to directly enable
4: Activate the service. telnet is stored under xinetd. Therefore, reactivate xinetd and run the Command Service xinetd restart.
5: OK. Go back to XP and connect remotely.
Finally, for the sake of security, remember to disable the Linux Telnet service after the experiment is completed.