How to monitor servers with broken TLS in Checkmk 2.3

Monitoring servers with damaged TLS (Transport Layer Security) is a key task in ensuring the security and reliability of IT infrastructure. Broken TLS connections can cause numerous problems, such as interruptions in communication between servers, the inability to secure data transmitted over the network, and opening the door for potential cyber attacks. Checkmk 2.3, a state-of-the-art system monitoring tool, offers a number of features to detect and monitor TLS problems. We suggest how to monitor servers with broken TLS in Checkmk 2.3.

In this article, we’ll take a step-by-step look at how to monitor servers with broken TLS in Checkmk 2.3, how to identify the most common TLS issues, and how to set up monitoring to minimize the risk of downtime and threats.

Table of Contents:

1. Introduction to TLS
2. Why is corrupt TLS a problem?
3. TLS monitoring in Checkmk 2.3
4. Checkmk’s TLS analysis tools
5. Advanced TLS monitoring scenarios
6. Frequently asked questions

Introduction to TLS

Transport Layer Security (TLS) is a cryptographic security protocol that ensures the privacy and integrity of data transmitted over the Internet. It was designed to replace its predecessor SSL (Secure Sockets Layer). It is now widely used to secure network connections. Especially in applications such as web browsing, e-mail, file transfer and others.

TLS is based on encryption and digital certificates. This ensures that the data sent between the client and server is protected from eavesdropping and modification. If the TLS connection is damaged or malfunctions, data is exposed to attacks or the server may fail to serve users.

Why is corrupt TLS a problem?

When TLS is corrupted, it can lead to several significant problems:

• Lack of data encryption – A faulty TLS connection means that the data sent between the client and the server is not encrypted properly. This exposes them to eavesdropping by third parties.
• Security threat – A damaged TLS can lead to vulnerabilities to man-in-the-middle attacks, where attackers can intercept and modify data.
• Lack of regulatory compliance – Many regulations, such as GDPR and HIPAA, require adequate data security in transit. Broken TLS connections can lead to regulatory violations.
• Service availability problems – Servers with broken TLS may not be able to handle user requests, leading to downtime and application availability problems.

TLS monitoring in Checkmk 2.3

Checkmk 2.3 offers advanced monitoring features to keep track of the status of TLS connections on servers. It ensures that any problems are detected immediately. The tool can automatically monitor SSL/TLS connections, alert in case of failures, and monitor expiring SSL certificates.

TLS monitoring configuration

To start monitoring servers with TLS in Checkmk 2.3, you need to perform the following steps:

1. Adding a host: Make sure that the server you want to monitor is added as a host in Checkmk.
2. Configure HTTPS monitoring: Using the built-in Checkmk plugin, you can configure monitoring of HTTPS connections that use TLS.
3. Defining services: Defining exactly what TLS services are to be monitored. We can monitor the status of HTTPS connections, the validity of SSL certificates, and potential problems with TLS implementation.

Defining TLS services

In Checkmk, you can configure various TLS monitoring services, which allow you to have full control over connections and certificates:

• HTTPS monitoring: A basic service that allows you to monitor the status of HTTPS connections, which also includes TLS status monitoring.
• SSL Certificates: Checkmk allows you to monitor the expiration dates of SSL certificates to avoid unexpected certificate expiration.
• TLS Vulnerability Analysis: Monitor vulnerabilities to known TLS threats, such as older versions of the protocol or unsafe encryption algorithms.

TLS failure alerts and notifications

Checkmk 2.3 offers an advanced alert and notification system to quickly inform administrators in case of TLS problems. You can configure notifications based on the following scenarios:

• Expiring Certificates: Checkmk will notify you in good time when your SSL certificate is nearing expiration, giving you time to renew it.
• TLS connection problems: If the TLS connection fails or the server stops responding, Checkmk immediately sends a notification.
• Vulnerabilities: Checkmk can monitor TLS vulnerabilities, such as the use of older versions of the protocol or unsafe encryption algorithms.

Checkmk’s TLS analysis tools

Check HTTPS

One of the key tools in Checkmk for monitoring TLS is. Check HTTPS. It is a built-in plugin that automatically monitors the status of HTTPS connections on servers, including TLS status. Check HTTPS allows you to:

• SSL certificate monitoring: Automatic monitoring of SSL certificates, their validity and compatibility with current versions of the TLS protocol.
• Monitoring connection status: Checking that HTTPS connections are working properly and that there are no TLS errors.
• Threat Alerting: Check HTTPS sends alerts about security problems with TLS connections.

SSL certificate monitoring

SSL certificates are a key component for securing TLS connections. Checkmk 2.3 allows you to monitor the status of SSL certificates and their expiration dates. SSL certificate monitoring features include:

• Certificate Validity: Automatically monitor the expiration date of the certificate and alert you before it expires.
• Certificate Compliance: Checkmk checks the SSL certificate’s compliance with the latest standards and norms. This avoids security problems and incompatibility with current versions of TLS protocols.
• Certificate threats: Checkmk can also monitor potential certificate threats, such as the use of outdated encryption algorithms or cryptographic keys that are too short.

Advanced TLS monitoring scenarios

TLS monitoring in Checkmk 2.3 is not limited to basic functions. It is possible to implement advanced monitoring scenarios to further manage the security of your IT infrastructure.

Integration with other tools

Checkmk 2.3 can be integrated with other monitoring and analysis tools. This allows you to get a complete picture of the status of TLS on servers. The most commonly used tools include:

• Nagios: Checkmk offers compatibility with Nagios, allowing integration with existing monitoring infrastructure.
• Grafana: Integration with Grafana enables visualization of Checkmk data, including data related to TLS monitoring.
• Elastic Stack (ELK): The ability to integrate with Elastic Stack allows for more detailed analysis of logs related to TLS and SSL certificates. This makes it easier to track issues and threats.

TLS incident reporting and analysis

Checkmk 2.3 offers tools to generate Reports and conduct incident analysis related to failed TLS connections. These reports may include:

• TLS failure statistics: Data on the frequency of failures, sources of problems, and incident response times.
• SSL certificate change history: Checkmk tracks changes to SSL certificates, allowing you to better control their management and audit changes.
• TLS Vulnerability Reporting: the TLS monitoring system allows reporting of vulnerabilities to attacks such as POODLE, BEAST or other attacks on old versions of SSL/TLS.

These reports are extremely important for security audits and to ensure compliance with regulations such as GDPR and PCI-DSS.

Frequently asked questions

1. What are the most common TLS-related problems?

The most common problems with TLS are:

• SSL certificate expiration: When an SSL certificate expires, TLS connections are unsecured, leaving data vulnerable to attacks.
• Server misconfiguration: Servers may be configured with incompatible versions of TLS, leading to connection problems.
• Vulnerability to attacks: Using older versions of TLS, such as TLS 1.0 or TLS 1.1, exposes systems to hacking attacks.

2. Does Checkmk automatically detect TLS problems?

Yes, Checkmk 2.3 has built-in mechanisms that automatically monitor TLS connections and SSL certificates. In case of problems, such as an expiring certificate or a broken TLS connection, Checkmk generates appropriate alerts. It does this so that administrators can take corrective action.

3. How can I check when my SSL certificate expires?

In Checkmk 2.3, it is possible to monitor the expiration date of an SSL certificate through the appropriate settings in the Check HTTPS plugin. This tool automatically generates notifications when the certificate expiration date is approaching, giving administrators time to renew the certificate.

4. What versions of TLS are supported by Checkmk 2.3?

Checkmk 2.3 supports all current versions of TLS, including TLS 1.2 and TLS 1.3, and can also monitor older versions such as TLS 1.0 and TLS 1.1. The tool also monitors potential risks from using older versions of the protocol.

5. Can I integrate Checkmk with other monitoring tools?

Yes, Checkmk 2.3 can be integrated with many popular monitoring tools, such as Nagios, Grafana and Elastic Stack. This integration provides even more detailed data on TLS status and enhances analysis and incident reporting capabilities.

What are the best practices when monitoring TLS?

Best practices for monitoring TLS include:

• Regularly check the validity of SSL certificates: Make sure you monitor certificate expiration dates and renew them regularly.
• Use the latest versions of TLS: Avoid using older versions of TLS, which are vulnerable to attacks.

Configure automatic alerts: Configure Checkmk to send alerts when it detects problems with TLS connections or expiring certificates.