How to Check and Manage SSH Daemon in AIX and Restart sshd

How to Check SSH Status in AIX and Manage the SSH Daemon

In this article, we'll walk you through how to check the status of SSH (Secure Shell) on AIX systems. You will learn how to confirm if the SSH daemon (sshd) is running, and how to start or stop it using simple commands. One of the primary tools for this task in AIX is the lssrc command, which is used to check the status of various system processes.

 

Checking SSH Status in AIX with lssrc

AIX provides the lssrc command, which lists subsystem processes, their associated process groups, process IDs, and their status (active, inactive, etc.). It’s an effective tool to check whether critical services such as sshd, syslogd, inetd, and others are running.

 

Check SSH Daemon Status Using lssrc

To check if the SSH daemon (sshd) is running, you can use the following lssrc command:

# lssrc -s sshd
Subsystem         Group            PID          Status
sshd              ssh              7864646      active

This will return information about the SSH daemon, including its PID (Process ID) and status. If the status is active, it means that the SSH daemon is running, and your system is ready to accept SSH connections.

To confirm the command's success, you can check the exit status of lssrc by running:

# echo $?
0

If the return code is 0, it indicates that the command was successful and the SSH daemon is active.

 

Using ps Command to Check SSH Process

Another simple method to check if the SSH daemon is running is by using the ps command to list processes. You can filter the results for sshd:

# ps -ef | grep sshd
root 7864646 2884302   0 08:29:12      -  0:00 /usr/sbin/sshd

If the SSH daemon is running, this will show you the process ID of sshd.

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How to Stop SSH Daemon Using stopsrc

Sometimes, you might need to stop the SSH daemon, for instance, during maintenance or troubleshooting. You can do this with the stopsrc command:

# stopsrc -s sshd
0513-044 The sshd Subsystem was requested to stop.

Once the SSH daemon has been stopped, you can verify its status using lssrc:

# lssrc -s sshd
Subsystem         Group            PID          Status
sshd              ssh                                  inoperative

Here, the status will be listed as inoperative, indicating that the SSH daemon is no longer running. Keep in mind that once stopped, no further SSH connections will be allowed until the service is restarted.

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How to Start SSH Daemon Using startsrc

If you find that the SSH daemon is not running or you’ve stopped it, you can easily restart it using the startsrc command:

# startsrc -s sshd
0513-059 The sshd Subsystem has been started. Subsystem PID is 8323392.

After starting the daemon, you can check its status again with the lssrc command:

# lssrc -s sshd
Subsystem         Group            PID          Status
sshd              ssh              8323392      active

Now, the SSH daemon should be active, and your system will be able to accept SSH connections once again.

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Summary

By using the lssrc command and other related commands, you can easily check and manage the SSH daemon (sshd) on an AIX system. Here's a quick rundown of the commands:

• Check if sshd is running:

  lssrc -s sshd
  

• Stop the sshd daemon:

  stopsrc -s sshd
  

• Start the sshd daemon:

  startsrc -s sshd
  

These commands will help you ensure that SSH is running smoothly on your AIX system and allow you to manage it efficiently.

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By following these steps, you can effectively manage the SSH service on your AIX system and ensure that it’s always available when you need to connect remotely.