HowTo: Raspberry Pi - Fix "SSH does not respond" or "is very slow" problem

Recently, after reinstalling Raspian on the RaspberryPi, I had the problem that access via SSH was painfully slow. Most of the time you could enter the user name and password “normally quickly”, but then it often took up to ten minutes until the usual welcome message was displayed.

To solve this problem the following solution helped me.

Safety instructions

I know the following notes are always kind of annoying and seem unnecessary. Unfortunately, many people who knew "better" have lost eyes, fingers or other things due to carelessness or injured themselves. Data loss is almost negligible in comparison, but even these can be really annoying. Therefore, please take five minutes to read the safety instructions. Because even the coolest project is not worth injury or other trouble.
https://www.nerdiy.de/sicherheitshinweise/

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Overview

Before you start with this article you should have prepared the RaspberryPi so that it is accessible via the network and controllable via SSH.

The following three articles describe what needs to be done to prepare the RaspberryPi:
RaspberryPi – setup for nerdiys!
RaspberryPi – The first configuration!
RaspberryPi – Control the RaspberryPi via SSH

Required tool:
-no-

Required material:

In the following list you will find all the parts you need to implement this article.

Log in to the RaspberryPi via SSH

To start, you must first log in to the Rasp Pi with Putty via SSH. How to do this is in the article RaspberryPi - Control the RaspberryPi via SSH described.

Change IPQoS value

This change fixes the bug that the SSH connection to your RaspberryPi becomes so slow after entering username and password that operation via the console is no longer possible.
This error only occurs if you access the RaspberryPi via a wireless network. It should not occur with a wired connection.

To fix it you need to enter a command or value change in two configuration files of your SSH client.

To do this, open the first configuration file with the command:

sudo nano /etc/ssh/ssh_config

IPQoS 0x00

Now repeat the same with the other configuration file. Open it with:

sudo nano /etc/ssh/sshd_config

... and inserts the value change “IPQoS 0x00” there. Save and close the file with “CTRL+X” and “Y” to confirm. After restarting the Raspberry Pi (command “sudo reboot”), your console connection should now be as fast as usual.

Change value with one command

“Kveldulfur” has left a comment that sometimes it is not possible to navigate to the setting of the value. In this case, the value can be set correctly using only one command. Just enter the following command.

echo "IPQoS 0X00" >> /etc/ssh/ssh_config && echo "IPQoS 0X00" >> /etc/ssh/sshd_config

After that restart your RaspberryPi and the console should respond faster.

Have fun with the project

I hope everything worked as described for you. If not or you have questions or suggestions please let me know in the comments. I will then add this to the article if necessary.
Ideas for new projects are always welcome. 🙂

PS Many of these projects - especially the hardware projects - cost a lot of time and money. Of course I do this because I enjoy it, but if you think it's cool that I share the information with you, I would be happy about a small donation to the coffee fund. 🙂