> Source: [sk167454](https://support.checkpoint.com/results/sk/sk167454)

# sk167454 - High CPU usage when clishd process overloads and many "sshd[xxxxx]: Connection closed by UNKNOWN" error messages in /var/log/messages

| Property | Value |
|----------|-------|
| Solution ID | sk167454 |
| Date Created | 2020-06-15 |
| Last Modified | 2020-06-21 |
| Technical Level | Advanced |
| Products | Security Gateway, Security Management Server |
| Versions | R82.10, R82, R81.20, R82.10, R82, R81.20, R82.20 |

## Symptoms

- High CPU usage when *clishd* process overloads and many "sshd\[xxxxx\]: Connection closed by UNKNOWN" error messages in */var/log/messages*

## Cause

Common causes are:   

* This message can be caused by a process performing an ssh client connection to *sshd*, but not supplying a password.
* This could be a user who lets the login screen timeout, or a piece of local or remote automated monitoring software simply checking that *sshd* is running by opening an *ssh* connection.

## Solution

This solution requires authentication. Please log in to view the full solution.

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