Notifications not being received

[scottwilkerson]

This line in the log

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==> /usr/local/nagiosxi/tmp/phpmailer.log <==
[11-13-2018 11:18:11] SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting (method=smtp;host=service.snapon.com;port=25;security=none),

looks like Nagios XI was unable to connect to service.snapon.com on port 25 to deliver the mail.

Please verify all setting are correct in Admin -> Manage Email Settings for this server

Also, if it is happening randomly you could be experiencing problems with the SMTP server

[snapon_admin]

Please verify all setting are correct in Admin -> Manage Email Settings for this server

If they weren't, wouldn't nobody get emails? The issue is that some people are receiving these and some are not, and not even all the time. As an example, Operations will somtiems receive a critical alert for a specific service and other times will not receive that same alert.

[scottwilkerson]

If they weren't, wouldn't nobody get emails?

this is true unless you have a mixed environment where some contacts are using different notification handlers, which is why I also mentioned this:

Also, if it is happening randomly you could be experiencing problems with the SMTP server

[snapon_admin]

I'm fairly certain all contacts are using the same notification handlers, they should lal be the xi_generic one that is added when a new contact is created since all contacts are added the same way.

[scottwilkerson]

This would then just leave possible problems with the SMTP server or connection on the network since the Nagios server was unable to successfully connect to the SMTP server per the phpmailer.log

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==> /usr/local/nagiosxi/tmp/phpmailer.log <==
[11-13-2018 11:18:11] SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting (method=smtp;host=service.snapon.com;port=25;security=none),

Have you looked into possible intermittent connection problems with the SMTP server?

[snapon_admin]

Not yet, I honestly have no idea what to ask them to look for with this issue being so random and intermittent. Is there anything I can check on the Nagios side of things to see what might be causing it? Since there's no other email related issues on the network this seems like something between Nagios and the SMTP server, but nothing's changed on the network between those 2 things and this issue is only very recently been occuring.

[scottwilkerson]

Not yet, I honestly have no idea what to ask them to look for with this issue being so random and intermittent. Is there anything I can check on the Nagios side of things to see what might be causing it? Since there's no other email related issues on the network this seems like something between Nagios and the SMTP server, but nothing's changed on the network between those 2 things and this issue is only very recently been occuring.

Really the only things to check on the Nagios server side, I have already suggested, and we have the log showing it could not make the connection.

As long as the server information is correct, I don't have any other suggestions on the Nagios side of things.

[snapon_admin]

Ok so I heard back from my Email team. It looks like the Nagios server is connecting using TLS 1.0 and our exchange servers are using TLS 1.2. Is there a way to force Nagios to use TLS 1.2 instead?

[snapon_admin]

Also, how do I update openssl on this server? It doesn't seem to want to update:

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[root@lisl-ngos-01-pv ~]# yum update openssl
Loaded plugins: fastestmirror, security
Setting up Update Process
Loading mirror speeds from cached hostfile
 * base: ftp.osuosl.org
 * epel: mirror.cogentco.com
 * extras: mirror.tzulo.com
 * updates: ftp.osuosl.org
No Packages marked for Update

Another strange thing is My email settings are setup to use no security. When I set it to TLS emails fail completely. With it set to "none", though I can send emails, but according to the packet capture TLS 1.0 is being used.

[scottwilkerson]

What php version are you using?

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php -v

What version of openssl does your server have installed

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yum list installed openssl

With it set to "none", though I can send emails, but according to the packet capture TLS 1.0 is being used.

The mailer will automatically try to detect is TLS is enabled on the server and us it if possible.

I know we did upgrade the PHPMailer in 5.5.6 of XI but not sure if this resolved any issues.

As far as I know PHPMailer tries to negotiate the highest available TLS version between the server and the client, however I'm not 100% sure but you may need php 5.6 to use TLS 1.2. I know for sure the openssl version has to be 1.0.1 or higher