Hosts.deny and hosts.allow configuration files can be cited as the major cause of ssh_exchange_identification: Connection closed by remote host error. However, there are certainly other causes which led to this annoying issue. If you are reading this informative content, you might have already examined that both of these files are not blocking the IP address trying to access ssh on a remote server. You might get stuck to a dependency issue pertaining to the memory fragmentation or overloading of sessions arising from individual clients. But the best part is once you know how to fix this problem, you can remove this permanently. Therefore, go through this article carefully in order to resolve ssh_exchange_identification ‘connection closed by remote host’ issue.
Effortless Hacks to Fix ssh_exchange_identification ‘connection closed by remote host’ Issue:
Go through the below steps to fix the aforementioned issue seamlessly.
Fix 1: Resolving Missing Dependencies
If you encounter this ssh_exchange_identification: connection closed by remote host after updating OpenSSL or glibc, then it is sure that you are searching for a missing dependency. Then, you need to execute sudo lsof -n | grep ssh | grep DEL present in the command line at this juncture. You will get a list of open files. From that list, search for those that get deleted pertaining to the ssh daemon. If you don’t receive anything, then we advise you to make an attempt to restart the daemon or the system. You may wish to perform a restart if you don’t receive too many errors at the same time. However, you can ignore those problems safely related to run/user/1000/gvfs messages since it can cause absurd issues associated with the virtual system.
You can make an attempt to use apt-get, yum, or Pacman in order to update packages. Also, you can use it if you detect any dependencies as a part of the problem. If you use Ubuntu or Debian-based systems, you may like to use a sudo-apt-get-f upgrade and examine whether it can fix any broken packages.
Fix 2: Rectifying Memory Fragmentation
If the previous procedure doesn’t work, then you might encounter an issue present on the host side of the equation. The host file generally runs inside the VM that lacks a swap partition causing memory fragmentation. You can use the host through different means and then you can reboot the services. It might happen that MySQL, Apache or Nginx are the major cause behind this annoying issue. It is not always convenient for you to restart the host. This can lead to some problems and it will be a fruitful idea if you are dealing alternately with the error message and the one which comes with the IP address. Always take into consideration that if the server is accessible, then it is viable to run vmstat-s command. You will get significant facts on memory usage, even as a regular user in different interfaces.
Fix 3: Examining Extra ssh Instances
Except this, you need to examine to ensure if the hosts can connect to the server or not. It might happen that you exceeded the permissible limit of ssh sessions unknowingly. Therefore, we advise you to clear the previous sessions and then start connecting. The most effective way to accomplish this is to execute the who command in order to check user processes are logged in or not. You will find that only one or two users already logged into it. However, if there are parallel ones, then you can kill the user processes and then you can make an attempt to login back.
It might happen that if the sshd can’t cope up with the script, it may lead to several ssh sessions in a loop. If this happens, then you can incorporate sleep 0.3 commands to the loop. This will keep up the sshd daemon.
Fix 4: Identifying sshd Connection Limit
Connection problems can take place when you attempt to use ssh in order to access the router. It might happen that another type of discrete box switch can cause this connection problem since there is a negligible number of connections. If you don’t wish to overload the server, you can search for the default setting.
To Sum it Up
This informative guide will help you to fix ssh_exchange_identification: ‘connection closed by remote host’ issue easily. If you follow this article step-by-step, you can surely be able to overcome the aforementioned issue. Moreover, you can refer to the user guide to have a quick glance. Also, if you have any innovative idea, do provide that in the comment section below.