Started getting the following error while running ./validate.php for LibreNMS
Cannot load Zend OPcache - it was already loaded
Looks like the problem arises out of PHP trying to load two ini files for OPcache. Was trying to enable OPcache for LibreNMS so I created an opcache.ini file and put the settings in it. I missed the default 10-opcache.ini file.
Moving all the settings into the 10-opcache.ini file and deleting the created opcache.ini file resolved the issue for me.
sudo ufw status numbered
To Action From -- ------ ----
 3478/udp ALLOW IN Anywhere
 5514/udp ALLOW IN Anywhere
 8080/tcp ALLOW IN Anywhere
 8443/tcp ALLOW IN Anywhere
 8880/tcp ALLOW IN Anywhere
 8843/tcp ALLOW IN Anywhere
 6789/tcp ALLOW IN Anywhere
 27117/tcp ALLOW IN Anywhere
 22/tcp ALLOW IN Anywhere
You need to know the number of the rule you want to delete. Replace number with the number of the rule from the status command
From the server side, edit the /etc/ssh/sshd_config
Change, uncomment, or add
ClientAliveInterval 120 ClientAliveCountMax 15
Change the AliveInterval and CountMax as desired.
More info on the AliveIntercal and CountMax.
ClientAliveCountMax Sets the number of client alive messages which may be sent without sshd(8) receiving any messages back from the client. If this threshold is reached while client alive messages are being sent, sshd will disconnect the client, terminating the session. It is important to note that the use of client alive messages is very different from TCPKeepAlive. The client alive messages are sent through the encrypted channel and therefore will not be spoofable. The TCP keepalive option enabled by TCPKeepAlive is spoofable. The client alive mechanism is valuable when the client or server depend on knowing when a connection has become unresponsive.
The default value is 3. If ClientAliveInterval is set to 15, and ClientAliveCountMax is left at the default, unresponsive SSH clients will be disconnected after approximately 45 seconds. Setting a zero
ClientAliveCountMax disables connection termination.ClientAliveInterval Sets a timeout interval in seconds after which if no data has been received from the client, sshd(8) will send a message through the encrypted channel to request a response from the client. The default is 0, indicating that these messages will not be sent to the client.