This guide explains how to avoid disconnecting for timeout after connecting with putty to a server. Putty is a Windows client that allows you to connect in SSH, RAW, Telnet, Rlogin, or in serial mode. This client is very used and I find it very useful because it provides a clean interface and a copy and paste system that I really appreciate.
First you need to connect with the putty to the server, then you need to click on the icon in the upper left to open the context menu. Then select “Change settings.” A window similar to the window you used to connect will open. In this window at the bottom left, select “Connection” and in the text box with the name “Seconds between Keepalive (0 you turn off)” you must enter the number “3”. Click the “Apply” button and you won’t be disconnected for this connection due to inactivity.
If you still have doubts about how to do this and I shouldn’t have been clear, you can view this short video to better understand how to do it.
In this video,you are shown how to prevent the putty client from shutting down. I think it might still be helpful to explain why this happens and not just how to avoid it through an in-depth analysis. Any element that connects to another needs to know if the interlocutor is still there and is receptive. In this case, the program that interfaces with the service is called a client and the specific name is putty. This app was developed by an English team composed, at the time of writing by Simon Tatham, Owen Dunn, Ben Harris and Jacob Nevins. It is a very simple program that is widely used in computing by all those people who do not want or can not give up getting their hands on an unix like system, without necessarily leaving Microsoft Windows.
What is putty
Putty is a suite of free clients and they are also distributed in portable form. Normally, however, in the jargon, when we talk about stucco, we refer to the secure shell client ssh. It’s definitely an application not to be missed in the classic USB stick of enthusiasts and professionals in the field. The suite then includes client ssh, scp, sftp, telnet, key generator and show. The telnet client is the classic method of connecting to old systems, it is important to understand that it can be done in any port, the important thing is that there is some compatibility and we know the commands. The ssh client is a more advanced system because it associates the encryption keys making the connection more secure. The client sftp establishes secure connections, it was created to compensate for the initial lack of cyptage from the ftp protocol, which has since been resolved. The PC instead is the traditional file exchange system in Linux systems, uses the same ssh encryption technology, it takes a while to learn how to use it. However, a visual client called winscp is also released that is quite intuitive and aesthetically similar to a ftp client. The key generator is responsible for generating the necessary keys for any secure shell connection, and the show stores them.
Since there is no automatic software update system, it is useful to always keep an eye on the putty developer site. The email address to contact the developers instead you can find it at the bottom of the putty bug page.
However, there are other programs to handle ssh connections on Windows, but now I am used to this and I will not change, also because putty can rely on a copy and paste system very similar to the linux system. Otherwise, in the other programs (many of these for a fee) I could not find the same comfort. However, this is a subjective thing that I imagine.
How Putty’s connection works
Putty is a client for connecting ssh, telnet and rlogin. Shssh is an acronym for the word “safe shell.” A shell, in the IT field, is a means by which the user communicates with the machine in a language more similar to that of human, than machine language. Putty allows you to establish a secure shell, telnet, and rlogin connection to interact with the server system by sending commands and viewing responses. I will try to explain under some rudiments very clearly at the price of seeming inaccurate. The purpose of this article is actually just to fix it.
Why the putty connection expires
The putty connection expires because, to avoid unnecessary suspended connections, a timeout is set on both the client and server side. If not, the connection would always remain active on the server side and therefore the ssh service would suffer from consuming resources unnecessarily due to processes that in all and everything are dead and aimless. Another reason for a putty disconnect might be related to a connection loss, temporary or not.
Why the proposed solution to avoid putty disconnection works
As already written, putty checks to verify that the server-side connection is still active. Because it does not transmit anything by default when it is in a resting state, when called, such as pressing a command on the keyboard, it detects that the server-side connection is no longer available and releases a timeout message. Obviously the developers predicted this thing and gave the opportunity to send a signal to the server to warn it that it is not in a state of permanent inactivity. Then, if you set the value to 1, every second this message will be sent to the ssh server that will keep the channel open and available for that connection.