When evaluating Nagios XI vs Icinga 2, one important distinction often gets lost: many comparisons evaluate alternatives against Nagios Core, our free open-source monitoring engine, rather than Nagios XI, our full enterprise platform. That framing skews the picture.

This article breaks down how Nagios XI stacks up on the factors that matter most: cost, deployment, scalability, and configuration.

Why Teams Choose Nagios XI Over Icinga 2

Nagios Core has been the basis for IT monitoring solutions for the last two decades.

Its extensible plugin architecture has cemented it as the de facto industry leader. Yet, in interactions with enterprise customers, the following pain points were repeatedly brought to light: time-consuming configuration, custom dashboard development, configuration file hassle, and the need for vendor assistance with compliance.

Nagios XI was our answer to these challenges. Nagios took the tried-and-true Nagios Core monitoring engine and packaged it with an enterprise monitoring platform featuring Configuration Wizards, native dashboards, Auto-Discovery tools, and commercial support with service-level agreements.

A critical decision was to ensure robust backward compatibility with Nagios Core to make it seamless for existing Nagios customers to upgrade. Read more about Nagios XI enterprise features and capabilities.

Nagios XI vs. Icinga 2 Pricing: What Icinga’s ‘Free’ Actually Costs

One of the most frequently asked questions is:

“Why pay for Nagios XI if Icinga 2 is free?”

While a free open-source solution may seem appealing at first glance, the opportunity cost is often underestimated. Time spent on manual installation, configuration, ongoing maintenance, and troubleshooting can accumulate quickly — particularly for teams without deep Linux expertise.

For organizations where uptime and operational continuity are priorities, that hidden cost frequently outweighs the savings on licensing.

Icinga 2’s core software is free, but enterprise-level support incurs significant costs. For teams that rely on support to maintain production monitoring, total expenses can escalate quickly.

Typical costs include:

• Enterprise modules: €2,000/year.
• Enterprise support: €15,000–€30,000/year.
• Repository subscription (Enterprise Linux): €5,000/year.

Five-Year Total Cost Example (500-node deployment):

Based on published five-year pricing, Nagios XI with enterprise support included represents roughly 25–40% of Icinga’s total cost, with support bundled into the license.

Use the Nagios XI plan calculator to determine the price based on your deployment size.

Migrating from Nagios or Icinga? Here’s the Difference

Migrating from Nagios Core to Nagios XI is seamless. XI supports direct import of existing configurations, object definitions, and plugins without requiring a new syntax or language. Many teams complete migration within hours or a few days, preserving years of monitoring expertise.

Nagios provides automatic migration tools to streamline the process. For a full walkthrough:

• Step-by-step migration guide (PDF)
• Migration from Nagios Core to Nagios XI (video)
  

Migrating from Nagios to Icinga 2, by contrast, requires manual conversion into Icinga’s domain-specific language (DSL). Icinga’s official migration documentation explicitly states that scripted one-to-one conversion is not possible due to the volume of behavioral changes introduced by Icinga 2’s architectural rewrite.

Command definitions, notifications, and object relationships often need to be rebuilt from scratch.

For existing Nagios Core users, Nagios XI preserves your time, expertise, and historical configurations — ensuring the transition is fast and low-risk.*

*Some custom configurations in Nagios Core may not fully migrate automatically and could require manual adjustments.

Up and Running in Minutes

One of the clearest advantages in the Nagios XI vs Icinga 2 comparison is deployment speed. Nagios XI is designed so your team can go from download to monitoring in under 20 minutes. Whether you’re building your own Linux machine or prefer one of Nagios’s prebuilt VM options for quick and simple installation, Nagios has you covered. Minimal Linux knowledge is required, and customers consistently describe it as easy to deploy with monitoring live within the hour.

For a visual walkthrough, see our Four Simple Methods of Installing Nagios XI video.

Icinga 2 requires multiple separate components for full functionality — a core engine, database backend, web interface, and additional configuration modules — each needing its own initialization and setup.

For most teams, this means several hours to a full day before monitoring is live, with additional integrations like InfluxDB and Grafana potentially pushing that timeline further.

Nagios XI gets you to ROI faster, with less risk and no lengthy setup delays.

Scale on Your Terms

Nagios XI scales from small deployments to monitoring hundreds of thousands of devices. Large-scale environments benefit from Nagios Fusion, our licensed solution that provides a centralized view across multiple Nagios XI or Core servers.

Nagios Fusion also integrates with Nagios Network Analyzer (network traffic) and Nagios Log Server (centralized logs), enabling multi-site deployments, high availability, and aggregated visibility of data from across geographically dispersed infrastructures.

For high-volume active checks, nagios‑mod‑gearman distributes check execution across multiple workers, improving throughput and performance.

Combined, these integrations allow organizations to consolidate performance, network, and log data into a single view — improving operational insight without added complexity.

With Nagios XI, you add capability as you need it — Fusion for multi-site visibility, nagios-mod-gearman for high-volume check distribution — keeping your environment as simple or as powerful as the moment requires.

Start small, scale on demand, and maintain full visibility and uptime every step of the way.

Configuration Philosophy: GUI‑First vs Code‑First

Nagios XI: GUI-First, Configuration Wizard-Driven

Nagios XI prioritizes a GUI-first approach with 90+ Configuration Wizards for common monitoring scenarios. Administrators can define hosts, services, and checks without writing text-based configurations.

The Core Configuration Manager (CCM) provides fine-grained control of your monitoring configs through an advanced GUI — ideal for teams preferring point-and-click workflows and lowering the barrier to entry for those without deep Linux expertise, while still supporting advanced customization when needed.

For more information, take a look at Nagios XI’s web architecture.

Icinga 2: Code-First with DSL and Optional GUI

Icinga 2 centers on a code-first approach using its domain-specific language (DSL), which supports variables, conditionals, loops, and functions — enabling automation and integration with tools like Ansible, Puppet, or Terraform. A GUI configuration option exists, but changes are ultimately translated into DSL code.

This approach is best suited for teams with strong Linux skills and established automation workflows.

For teams that want to get monitoring running quickly without deep scripting knowledge, Nagios XI’s wizard-driven approach delivers immediate value — with full flexibility available when you need it.

Try Nagios XI for Yourself

The Nagios XI vs Icinga 2 decision ultimately comes down to what your team needs today and how you plan to grow. Nagios XI delivers enterprise-grade monitoring with faster deployment, predictable costs, and the support structure production environments demand.

• Start a free 30-day trial – Full enterprise features, no credit card required.
• Calculate your Nagios XI plan – Estimates for your environment.
• Request A Demo – Explore XI in action.

Prerequisites

• Admin access to Nagios XI.
• Provider account ready (mailbox or SMTP relay access). For Microsoft 365 OAuth, you’ll need an App registration with Client ID/Secret and Tenant ID.
• Time sync: The XI host is NTP‑synchronized (avoids TLS handshake and token issues).
• Firewall/NAT: Allow outbound TCP on 587 (preferred) and/or 465 to the provider host. Port 25 should be used only when your relay policy explicitly allows it.
• Deliverability: Your sending domain publishes SPF, signs with DKIM, and enforces DMARC. If you run your own relay, ensure valid PTR (reverse DNS) and matching HELO name.
• From address policy: Use a dedicated sender like alerts@your-domain. Keep From and Envelope-From (Return‑Path) aligned to a domain you control.

Where to configure in XI

Nagios XI makes email setup straightforward. Navigate to these paths:

• Admin → System Config → Email Settings → SMTP with Basic Auth
• Admin → System Config → Email Settings → Gmail with OAuth2 (optional Gmail OAuth)
• Admin → System Config → Email Settings → Microsoft with OAuth2 (for Microsoft 365)

Quick Start for Any Provider

For a fast setup:

1. Navigate to Admin → System Config → Email Settings → SMTP with Basic Auth.

2. Fill in these key fields:

• SMTP Host: Your provider’s server, like smtp.gmail.com.
• Port: 587 for TLS/STARTTLS or 465 for SSL/TLS, depending on what’s required.
• Security: Choose TLS (STARTTLS) or SSL/TLS to match.
• Username: Typically your full email address (skip this for IP-allowlisted relays).
• Password: Your account password or an App Password—switch to OAuth tabs if supported.
• Send Mail From: Something clear like Nagios Alerts <alerts@your-domain.com>.

3. Hit Test Settings to send a quick email and check if it lands.

Quick tip: If you’re sending on behalf of a shared mailbox or different address, verify “Send As” permissions with your provider to avoid bounces.

Provider-Specific Setups

Email providers keep updating their rules, especially in 2025 with a big shift toward OAuth over basic auth for better security. We’ve pulled these configs from official sources and tested them to ensure they’re solid.

Gmail (Personal @gmail.com Accounts)

For personal Gmail, the easiest secure option is an App Password, paired with two-step verification.

1. Enable two-step verification in your Google account settings.

2. Generate an App Password called “Nagios XI” and copy that 16-character code.

3. In Nagios XI’s SMTP section:

• Host: smtp.gmail.com
• Port/Security: 587 with TLS (STARTTLS) or 465 with SSL/TLS.
• Username: Your full Gmail address.
• Password: The App Password (Generated 16-character code).
• From: Your Gmail address or a verified alias.

Run Test Settings to confirm.

If your organization insists on OAuth, use the Gmail with OAuth2 tab and follow the prompts with your Google Cloud Client ID and Secret.

Common hiccups: “535 5.7.8 Username and Password not accepted” usually means double-check two-step verification is on and you’re using the App Password. “Must issue a STARTTLS command first”? Switch to 587/TLS.

This video walks through setting up email notifications with Gmail.

Google Workspace (Business Accounts)

Business users get the best results with Google Workspace’s SMTP relay, especially if you can set up IP allow listing for no-fuss auth.

• Server: smtp-relay.gmail.com
• Port: 587 (recommended with STARTTLS), 465 (SSL/TLS), or 25 (opportunistic TLS).
• Security: Matches the port—opportunistic on 25, STARTTLS on 587, SSL/TLS on 465.
• Authentication: Skip username/password if IP allowlisting is in play; just align your “From” with the policy.

Microsoft 365

Microsoft 365 is all about OAuth these days for top-notch security via the Microsoft Graph API.

1. In Microsoft Entra ID (formerly Azure AD):

• Set up an app registration and grab the Tenant ID and Client ID.
• Create a Client Secret and keep it safe.
• Add the “Mail.Send” permission under Microsoft Graph (Application type) and grant admin consent.

2. Back in Nagios XI’s Microsoft with OAuth2 tab:

• Plug in the Tenant ID, Client ID, and Secret.
• Set a valid “Send From” mailbox or alias.
• Click Test Credentials, then Test Settings.

Stick to modern TLS (1.2 or higher) and keep the “From” address in line with what’s authorized.

As a temporary bridge, you can fall back to SMTP AUTH on smtp.office365.com with port 587 and STARTTLS (no 465 here). Use a licensed mailbox’s UPN and password, but enable SMTP AUTH at both the org and mailbox levels, and grant “Send As” if needed. Heads up: Basic Auth for SMTP is getting the axe permanently in September 2025, so shift to OAuth ASAP.

Typical errors: “5.7.139 Authentication unsuccessful” or “5.7.0 Authentication required” points to enabling SMTP AUTH (if using it), checking UPN/password, and sticking to 587/STARTTLS. “5.7.60 Client does not have permissions to send as this sender”? Grant “Send As” or tweak the “From”.

Outlook.com

For personal Microsoft accounts like Outlook.com, Hotmail, or Live, keep it simple:

• Server: smtp-mail.outlook.com
• Port/Security: 587 with STARTTLS.
• Authentication: Your full address and password; switch to an App Password if two-step verification is on.

Read this article to learn more:

Yahoo Mail

Yahoo keeps third-party access secure with App Passwords.

1. Head to Yahoo Account Security and generate one named “Nagios XI”.

2. In Nagios XI SMTP:

• Host: smtp.mail.yahoo.com
• Port/Security: 465 with SSL/TLS or 587 with TLS.
• Username: Your full Yahoo address.
• Password: The App Password.
• From: Your Yahoo address.

Read this article to learn more:

Zoho Mail

Zoho’s setup varies by region and account type.

For standard accounts:

• Server: smtp.zoho.com for (US), smtp.zoho.eu for (EU), smtp.zoho.in for (IN).
• Port/Security: 465 with SSL/TLS or 587 with TLS.
• Authentication: Email and password; use a Zoho App Password if MFA is enabled.
• From: Your Zoho address or allowed alias.

Organizations on paid plans might use smtppro.zoho.com with the same ports and security.

Read this article to learn more:

Custom SMTP / Internal Relay

For custom setups, loop in your mail team to get:

• The hostname (FQDN), port, TLS mode, and auth method.
• Policies for allowed From/Return-Path.
• IP allowlisting or certificate rules.
• Limits on rates and message sizes.

To nail deliverability, publish SPF, sign with DKIM, enforce DMARC, and ensure PTR and HELO match up.

Testing and Validation

Once configured, don’t skip testing; it’s the best way to catch issues early.

1. In the SMTP settings, click Test Settings and send to an email you can access.
2. Check both the Inbox and Spam/Junk folders.
3. If it flops, dive into the logs: /usr/local/nagiosxi/tmp/phpmailer.log for XI, or OS-specific ones.
4. For OAuth, head to the provider portal to validate tokens and credentials.

Handy CLI tools for extra checks:

# Probe STARTTLS for Microsoft 365
openssl s_client -starttls smtp -connect smtp.office365.com:587 -brief

# Test Gmail SMTP auth with App Password
swaks --to you@domain --server smtp.gmail.com --port 587 --auth LOGIN \
  --auth-user your@gmail.com --auth-password 'your-app-password' --tls

# Generic STARTTLS check
openssl s_client -starttls smtp -connect host.example.com:587 -showcerts

# Probe STARTTLS for Microsoft 365
openssl s_client -starttls smtp -connect smtp.office365.com:587 -brief

# Test Gmail SMTP auth with App Password
swaks --to you@domain --server smtp.gmail.com --port 587 --auth LOGIN \
  --auth-user your@gmail.com --auth-password 'your-app-password' --tls

# Generic STARTTLS check
openssl s_client -starttls smtp -connect host.example.com:587 -showcerts

Troubleshooting

Most Common Issues and Fixes

• Authentication Failures: Stick to the right App Password (for Gmail, Yahoo, Zoho) or OAuth (Microsoft 365, Gmail). For Microsoft 365’s SMTP AUTH fallback, enable it at org and mailbox levels, use 587/STARTTLS, and verify UPN/password. Sending as another address? Grant “Send As” permissions.
• TLS or Connection Errors: Ensure ports 587 and/or 465 are open outbound. Your XI host needs TLS 1.2+ and fresh CA certs. Remember, no port 465 for Microsoft 365 client submission.
• Relaying Denied: Auth properly with username/password or OAuth, or lean on an IP-allowlisted relay. Align the “From” with policy rules.
• Google Workspace Relay: Prompted for a password? Your policy likely wants IP allowlisting; drop credentials and fix the “From” domain.
• Gmail: “535 5.7.8 Username and Password not accepted” → Confirm two-step is enabled and use the App Password.

Quick Reference Table

Conclusion

Reliable email notifications prevent minor issues from becoming outages in Nagios XI. Configure SMTP and OAuth using the provider-validated settings in this guide, prioritize OAuth 2.0 as Microsoft retires legacy methods in 2025, and maintain SPF/DKIM/DMARC alignment to safeguard deliverability. If tests fail, use the logging, CLI checks, and quick-fix steps here to diagnose and resolve issues quickly.

The test email is sent using SMTP, and the verification and deletion are done via IMAP.

This document provides step-by-step instructions and usage notes:

Here is a direct link to the PDF as well:

How to Use the Email Delivery Wizard in Nagios XI

This video provides a guided walk-through covering each step of how to use configuration Wizards:

You can also refer to this documentation for full details:

Here is a direct link to the PDF as well:

How to Use Configuration Wizards in Nagios XI

For years, Nagios dashboards have been the foundation of monitoring visibility, helping teams make informed decisions at a glance. Now, that experience has evolved even further. XI 2026 introduces up-to-date, customizable control centers built for modern infrastructure demands.

A Smarter Way to Visualize Data

At the heart of Smart Dashboards lies one goal: turning complex data into clear insight.
Every dashboard can be tailored to highlight the metrics and systems that matter most, with flexible layouts and a growing library of powerful dashlets.

Whether tracking uptime across distributed systems, comparing host performance, or visualizing alert patterns, Smart Dashboards make it effortless to understand the state of your network at a glance.

Smart Dashboards help reduce the time between detection and action by making system health obvious at first glance.

Introducing the New Dashlets

Smart Dashboards launch alongside a suite of new and improved dashlets, each built to deliver faster insights, cleaner visuals, and greater interactivity.

• Graph Dashlet – Visualize performance data over time, ideal for trend analysis.
• Bar Chart Dashlet – Compare hosts or services side by side for fast context.
• Gauge Dashlet – Monitor thresholds and utilization through an easy-to-read gauge.
• Pie Chart Dashlet – Display percentages and proportional data for quick breakdowns.
• Statistic Dashlet – Highlight key figures such as counts, totals, or averages.
• Text Dashlet – Add notes, context, or documentation directly to your dashboards.
• Treemap Dashlet – Understand hierarchical relationships and health status instantly.
• URL Dashlet – Embed external reports, internal tools, or live data sources.
• Alert Heatmap Dashlet – Identify recurring alerts and visualize problem frequency patterns over time.

Each dashlet is crafted to improve clarity and engagement, giving administrators the ability to design dashboards that are as informative as they are intuitive.

Enhanced Customization and Collaboration

Beyond the visual improvements, Nagios XI 2026 introduces new features that make Smart Dashboards more versatile and collaborative than ever:

• Global Dashboard Setting – Enable team-wide dashboards for unified visibility across departments and roles.
• Dashboard Wizards – Rapidly create and configure dashboards, supporting both Smart and Legacy types for a seamless experience.
• Custom Dashboard Icons and Colors – In the Neptune Theme, users can personalize icons and adjust color palettes for consistency and readability.
• Updated Dashboard Menu – Easily navigate between Smart and Legacy Dashboards across both the Modern and Neptune themes.

These additions make Smart Dashboards a shared monitoring experience rather than a personal view, empowering teams to coordinate, communicate, and respond faster to emerging issues.

Smart Dashboards and Legacy Compatibility

While Smart Dashboards represent the future of visualization in Nagios XI, Legacy Dashboards remain fully supported. This ensures that longtime users can continue relying on their existing workflows while exploring the new Smart Dashboard framework at their own pace. Legacy Dashboards still provide the classic layout and functionality that Nagios XI veterans trust, while Smart Dashboards introduce the next generation of interactivity, customization, and performance. Together, they offer a seamless bridge between past reliability and future innovation.

Why Smart Dashboards Matter

The introduction of Smart Dashboards isn’t just about aesthetics; it’s about efficiency and insight. In environments where rapid detection and resolution are critical, visual clarity can make the difference between proactive management and reactive firefighting. By combining intuitive layouts and global visibility, Smart Dashboards give teams a centralized, intelligent command center. The result is faster response times, clearer communication, and a more connected view of system health across the enterprise.

Nagios XI 2026 doesn’t just display data; it helps you understand it, prioritize it, and act on it faster.

The Future of Monitoring Visualization

From new dashlets and collaborative features to extensive customization, while still supporting legacy systems, this release sets a new standard for dashboards. Smart Dashboards bring together everything Nagios is known for: reliability, clarity, and control, all in a modern, intuitive interface.

Resources

If you are interested in using any of these great new dashboards and dashlets, below is a link to documentation to help get you started.

Understanding and Using Dashboards in Nagios XI 2026

You can also check out this video to learn more about creating and managing Smart Dashboards:

In this article, we’ll highlight the most impactful changes and provide helpful links to documentation so you can start exploring the new functionality right away. Let’s take a look!

Home Screen

The main Nagios XI home screen received several visual and functional improvements in the 2026 release, making it more than just a landing page—it’s now a true hub for navigation and monitoring. One of the most noticeable additions is the new Host Treemap, which provides a quick, color-coded overview of each host and its associated services. This intuitive, space-efficient dashlet makes it easier than ever to identify problem areas at a glance and monitor overall infrastructure health right from the dashboard.

In addition to visual updates, the homepage now includes helpful tabs: Getting Started, Admin, and Popular Wizards. These sections offer quick links to common tasks and important areas of Nagios, allowing new and experienced users alike to navigate more efficiently. Whether you’re setting up your first checks, managing users, or launching new Configuration Wizards, the updated homepage gets you there faster.

Customize the Landing Page in Nagios XI 2026

Smart Dashboards

A major highlight of XI 2026 is the introduction of Smart Dashboards—a next-generation dashboarding system built for flexibility, interactivity, and ease of use.

The Add Dashlet interface makes building Smart Dashboards faster and more intuitive. Dashlets are now organized by type with clear labels. Whether you’re dropping in graphs, gauges, statistics, or external content, the streamlined experience makes it easy to customize your dashboard with just a few clicks.

How To Use Dashboards in Nagios XI 2026

New and Improved Dashlets:

---

Graph Dashlet

Bar Chart Dashlet

Gauge Dashlet

Pie Chart Dashlet

Statistic Dashlet

Text Dashlet

Treemap Dashlet

URL Dashlet

Alert Heatmap Dashlet

In addition to new dashlets, this release introduces:

• A Global dashboard Setting, for team-wide Smart dashboards.
• Ability to customize dashboard icons and icon colors in the Neptune Theme.
• Updated Dashboards menu to support both Smart and Legacy Dashboards across Modern and Neptune Themes.
• Dashboard Wizards for both Smart and Legacy dashboards.

Quickly create and customize dashboards with the Dashboard Wizard—supporting both Smart and Legacy dashboards for a faster, more streamlined setup experience.

Added Google.com as default host

To help users get started with monitoring right out of the box, Google.com has been added as a default host in Nagios XI 2026. This provides an immediate example of website host and service monitoring in action, making it easier for beginner users to see how checks are configured and displayed—no setup required.

New Monitoring Wizards

Nagios XI 2026 continues to expand monitoring capabilities with a brand-new wizard:

• Meraki Switch Wizard – Quickly set up monitoring for Cisco Meraki Switches.

How To Monitor Meraki Switches With Nagios XI 2026

Quality of Life Improvements

• A new Getting Started notification welcomes new users with a link to documentation.
• New default host: Google.
• New default hostgroups: Websites, Switches.
• New default servicegroups: Web Services, SSL Certificates.
• Added support for experimental features toggle in Admin settings.
• Added a Re-run job feature to the SNMP Walk Jobs page.
• Improved app-wide error handling and logging.

Optional Statistics Tracking

XI 2026 introduces optional usage statistics tracking (opt-in/out) to help the Nagios Team better understand how the software is used, so future versions can be even more user-friendly.

Changelog

To review all the changes in detail, including security fixes and development notes, visit the full changelog here:

Nagios XI Changelog

Getting Started

If you’re new to Nagios XI or ready to upgrade to the 2026 release, download the trial version here:

Nagios XI Downloads

Another great resource is this article, which provides tips and resources on how to quickly get started using Nagios XI:

Quick Start Guide (Modern Theme)

If you’d like a personalized walkthrough of Nagios XI 2026 tailored to your specific environment, or a hands-on remote session with one of our technicians to help you get started, we’d love to offer you a Quickstart session or free Demo.

To schedule your session—or for any other assistance—just email us at sales@nagios.com. Our sales and technical teams are here to help you get the most out of your Nagios XI 2026 trial and ensure you’re set up for success!

1. Run a Wizard

To monitor a new host in Nagios XI, use the Configuration Wizards for simple setup without editing files manually. Start by navigating to Configure > Configuration Wizards or on the Home page you can find it under Getting Started > Run a Wizard.

Best Practices:

• Start with the Website Wizard to set up some basic monitoring and familiarize yourself with the wizard steps.
• Use a unique, descriptive Host Name (e.g., “Company Website – Prod”) for quick identification.
• Verify SSL settings if monitoring HTTPS sites to avoid certificate mismatch errors.

Read this document to learn more about How To Monitor Websites In Nagios XI 2024.

The video below provides a guided walk-through that covers how to monitor your first hosts in Nagios XI.

2. Mastering Wizards

Popular wizards in Nagios XI simplify monitoring setup for common items like servers and databases. Start by navigating to Configure > Configuration Wizards and search by category (e.g., Linux Server, Windows Server, Switch/Router, Website, MySQL).

Best Practices:

• Match the wizard to the host type for cultivated sets of relevant checks.
• Review the Understanding and Using Config Wizards document to master all of the steps and universal settings.

The video below provides a guided walk-through that covers how to monitor Active Directory in Nagios XI.

3. Account Settings

Updating settings in Nagios XI optimizes system performance and customizes the interface for maximum usability. Navigate to Home > Getting Started > Account Settings or click the User Icon > Nagios Admin to tweak performance, UI, or notification options.

Best Practices:

• Adjust performance settings for optimization.
• Test upgrades in a dev environment.
• Apply changes during low usage periods.

The video below provides a guided walk-through that covers the Admin interface.

4. Enable Notifications

Enabling notifications in Nagios XI delivers timely information about issues, reducing downtime through proactive responses. Configure them under Admin > Notification Management.

Best Practices:

• Use contact groups for easy bulk management.
• Set escalations for critical issues.
• Leverage retry intervals and parent/child relationships to reduce alert fatigue.

Read this document to learn more about Configuring Email And Text Notifications In Nagios XI 2024.

5. Email Settings

Setting up emails in Nagios XI enables reliable notification delivery via SMTP. Navigate to Admin > Email Settings to configure SMTP details.

Best Practices:

• Use TLS for secure transmission.
• Check spam/junk folders.
• Sync server time with NTP to prevent errors.

Related Readings: Nagios XI Email Notifications with Zoho Mail SMTP: 2025 Guide

The video below provides a guided walk-through that cover setting up email notifications.

6. Manage Users

Managing users in Nagios XI ensures proper access control and security through roles and permissions. Access this by navigating to Admin > Manage Users.

Best Practices:

• Apply the principle of least privilege.
• Use contact groups to simplify notifications.
• Regularly audit and review permissions for security.

Related Reading: Set Up User Roles and Permissions in Nagios XI in 4 Easy Steps.

The video below provides a guided walk-through that covers how to add a new user in Nagios XI.

7. Leverage Dashboards

Dashboards in Nagios XI provide customizable, responsive views of monitoring data (dashlets are modular widgets for metrics). For detailed instructions, see the How to Use Nagios XI Dashboards 2026 document.

Best Practices:

• Create some Global dashboards for team collaboration.
• Explore the many dashlets available in both Legacy and Smart dashboards.
• Create an XI server status dashboard using either dashlets from the Server Stats section of Smart options or dashlets such as Monitoring Engine Performance, Monitoring Engine Stats, and Server Stats in your Legacy dashboards.
• Explore creating custom dashlets; secure custom dashlet code with htmlspecialchars() and use PDO for SQL queries.

The video below provides a guided walk-through that covers each step of how to use Legacy dashboards in Nagios XI.

8. Explore the Core Config Manager

The Core Config Manager (CCM) in Nagios XI allows advanced management of hosts and services for efficient infrastructure organization. Access this by navigating to Configure > Core Config Manager.

Best Practices:

• Use hostgroups and servicegroups for efficient definitions.
• Implement templates for consistency.
• Avoid overlapping groups.
• Set proper check intervals based on deployment scale.

Read this document to learn more about Using the Core Config Manager for Host Management in Nagios XI 2024.

9. Run Auto-discovery

The Auto-Discovery Wizard in Nagios XI automatically detects network devices using Nmap for faster setup and visibility of what’s on your network.

Best Practices:

• Scan targeted IP ranges to avoid overload.
• Provide credentials for deeper discovery.
• Review and filter results before applying.
• Combine with wizards for quick monitoring setup.

Read this document to learn more about How To Use Nagios XI 2024 Auto-Discovery.

10. Getting Help with Nagios XI

For additional support, Nagios offers several resources to assist users:

• Quickstart Remote Sessions: Schedule a guided remote session with Nagios experts to accelerate setup and configuration. Visit Nagios Quickstart to book a session.
• Custom Demos: Request a personalized demo tailored to your monitoring needs or contact the Nagios team at sales@nagios.com.
• Pin the Admin Guide: The Admin Guide provides a directory of foundational documentation.
• Community and Documentation: Explore the Nagios Community Support Forum for user-contributed solutions, or refer to the official Nagios Documentation.
• Direct Support: For specific inquiries or technical assistance, reach out to the Nagios sales team at sales@nagios.com for prompt support.

Conclusion

Nagios XI with the Modern theme empowers efficient, scalable monitoring. This quick start guide equips you to add hosts, configure settings, enable notifications, manage users, and more. Start simple, scale as needed, and refer to the Nagios Library for advanced topics. For support, visit the Nagios Community Support Forums or contact sales@nagios.com.

1. Monitor a New Host

To monitor a new host in Nagios XI, use Configuration Wizards for simple setup without editing files manually. Start by navigating to Configure > Configuration Wizards or on the Home page you can find it under Getting Started > Monitor a new host.

Best Practices:

• Start with the Website wizard to set up some basic monitoring and familiarize yourself with the wizard steps.
• Use a unique, descriptive Host Name (e.g., “Company Website – Prod”) for quick identification.
• Verify SSL settings if monitoring HTTPS sites to avoid certificate mismatch errors.

Read this document to learn more about How To Monitor Websites In Nagios XI 2024.

The video below provides a guided walk-through that covers how to monitor your first hosts in Nagios XI.

2. Mastering Wizards

Popular wizards in Nagios XI simplify monitoring setup for common items like servers and databases. Start by navigating to Configure > Configuration Wizards and search by category (e.g., Linux Server, Windows Server, Switch/Router, Website, MySQL).

Best Practices:

• Match the wizard to the host type for cultivated sets of relevant checks.
• Review the Understanding and Using Configuration Wizards document to master all of the steps and universal settings.

The video below provides a guided walk-through that covers how to use Configuration Wizards in Nagios XI.

3. Update Your Settings

Updating settings in Nagios XI optimizes system performance and customizes the interface for maximum usability. Go to Home > Getting Started > Update your settings or click the User Icon > Account Settings (as Nagios Admin or your user).

Best Practices:

• Adjust performance settings for optimization.
• Test upgrades in a dev environment.
• Apply changes during low usage periods.

The video below provides a guided walk-through that covers the Admin interface.

4. Enable Notifications

Enabling notifications in Nagios XI delivers timely information about issues, reducing downtime through proactive responses. Configure them under Admin > Notification Management.

Best Practices:

• Use contact groups for easy management.
• Set escalations for critical issues.
• Leverage retry intervals and parent/child relationships to reduce alert fatigue.

Read this document to learn more about Configuring Email And Text Notifications In Nagios XI 2024.

The video below provides a guided walk-through that covers configuring notification methods in Nagios XI.

5. Set Up Emails

Setting up emails in Nagios XI enables reliable notification delivery via SMTP. Navigate to Admin > Email Settings and input your SMTP details.

Best Practices:

• Use TLS for secure transmission.
• Check spam/junk folders.
• Sync server time with NTP to prevent errors.

Related Readings : Nagios XI Email Notifications with Zoho Mail SMTP: 2025 Guide

The video below provides a guided walk-through that cover setting up email notifications.

6. Manage Users

Managing users in Nagios XI ensures proper access control and security through roles and permissions. Access this via Admin > Manage Users.

Best Practices:

• Apply the principle of least privilege.
• Use contact groups to simplify notifications.
• Regularly audit and review permissions for security.

Related Reading: Set Up User Roles and Permissions in Nagios XI in 4 Easy Steps.

The video below provides a guided walk-through that covers how to add a new user in Nagios XI.

7. Leverage Dashboards

Dashboards in Nagios XI provide customizable, responsive views of monitoring data (dashlets are modular widgets for metrics). For detailed instructions, see the How to Use Nagios XI Dashboards 2026 document.

Best Practices:

• Create some Global dashboards for team collaboration.
• Explore the many dashlets available in both Legacy and Smart dashboards.
• Create an XI server status dashboard using either dashlets from Server Stats section of Smart options or dashlets such as Monitoring Engine Performance, Monitoring Engine Stats, and Server Stats in your Legacy dashboards.
• Explore creating custom dashlets; secure custom dashlet code with htmlspecialchars() and use PDO for SQL queries.

This video provides a guided walk-through of using Smart dashboards in Nagios XI:

8. Manage Hosts and Services

The Core Config Manager (CCM) in Nagios XI allows advanced management of hosts and services for efficient infrastructure organization. Access via Configure > Core Config Manager.

Best Practices:

• Use hostgroups and servicegroups for efficient definitions.
• Implement templates for consistency.
• Avoid overlapping groups.
• Set proper check intervals based on deployment scale.

The video below provides a guided walk-through that covers the basics of hosts and services in Nagios XI.

9. Run Auto-discovery

The Auto-Discovery Wizard in Nagios XI automatically detects network devices using Nmap for faster setup and visibility of what’s on your network.

Best Practices:

• Scan targeted IP ranges to avoid overload.
• Provide credentials for deeper discovery.
• Review and filter results before applying.
• Combine with wizards for quick monitoring setup.

Read this document to learn more about How To Use Nagios XI 2024 Auto-Discovery.

The video below provides a guided walk-through that covers how to use Auto-Discovery in Nagios XI.

10. Getting Help with Nagios XI

For additional support, Nagios offers several resources to assist users:

• Quickstart Remote Sessions: Schedule a guided remote session with Nagios experts to accelerate setup and configuration. Visit Nagios Quickstart to book a session.
• Custom Demos: Request a personalized demo tailored to your monitoring needs or contact the Nagios team at sales@nagios.com.
• Pin the Admin Guide: the Admin Guide provides a directory of foundational documentation.
• Community and Documentation: Explore the Nagios Community Support Forums for user-contributed solutions, or refer to the official Nagios Documentation.
• Direct Support: For specific inquiries or technical assistance, reach out to the Nagios sales team at sales@nagios.com for prompt support.

Conclusion

Nagios XI with the Neptune theme empowers efficient, scalable monitoring. This quick start guide equips you to add hosts, configure settings, enable notifications, manage users, and more. Start simple, scale as needed, and refer to the Nagios Library for advanced topics. For support, visit the Nagios Community Support Forums or contact sales@nagios.com.

You can also refer to this documentation for full details:

Here is a direct link to the PDF as well:

How To Monitor Meraki Switches With Nagios XI 2026

Prerequisites

• Outlook mailbox that will appear in the From line (e.g., alerts@your-domain.com).
• MFA enabled on the sending account and tenant policy that allows app passwords.
• Nagios XI admin access and outbound network access from the XI server to smtp.office365.com on port 587 (STARTTLS).
• Accurate time/NTP and up-to-date CA certificates on the XI host to avoid TLS/certificate issues.

Step 1: Enable MFA and Generate a Microsoft 365 App Password

1. Sign in to your Security info page for your work/school account and ensure two-step verification (MFA) is enabled.
2. In Security info, select Add method → App password, then choose Generate app password. Name it “Nagios XI” or another memorable name if you have multiple app passwords.
3. Copy the app password and store it securely for use in Nagios XI. Do not use your regular account password, and ensure no extra spaces are copied.

If App password isn’t available, your tenant likely blocks app passwords (Security Defaults or conditional access policy). Use Microsoft with OAuth2 in XI or an SMTP relay instead.

Step 2: Configure SMTP Settings in Nagios XI

1. In XI, go to Admin → System Config → Email Settings.
2. Set Send Mail From to a valid sender in your tenant, for example: Nagios Alerts <alerts@your-domain.com>.
3. Mail Method: SMTP.
4. Configure SMTP Settings:
   • Host: smtp.office365.com
   • Port: 587
   • Security: TLS
   • Username: full mailbox UPN (e.g., alerts@your-domain.com)
   • Password: the app password from Step 1
5. Click Update Settings.

If the test later fails with “client not authenticated” or 5.7.139, confirm Authenticated SMTP is enabled for the mailbox/tenant and that you are using STARTTLS on 587.

Step 3: Update User Email in Account Settings

1. In XI, click the user icon → Account Settings.
2. Update Email Address to the address that should receive notifications (e.g., alerts@your-domain.com or another inbox).
3. Enter your current XI password to confirm.
4. Click Update Settings.

Step 4: Send a Test Email

1. Return to Admin → System Config → Email Settings.

2. Click Send A Test Email to verify the SMTP configuration.

3. Check the destination inbox and Spam/Junk folder for the test message.

Step 5: Test Notifications with a Real Alert

1. Assign the Microsoft 365–backed contact to a test host or service in XI.
2. Trigger an alert (e.g., force a soft problem state or use Send Custom Notification).
3. Verify that the alert email arrives (check Spam/Junk inbox if needed).

Troubleshooting

Conclusion

Microsoft 365 App Password + SMTP AUTH can deliver Nagios XI notifications securely over TLS on port 587 with smtp.office365.com, but it depends on tenant policies that allow app passwords and Authenticated SMTP. Because Microsoft is phasing out Basic Authentication for SMTP client submission, treat app passwords as a short‑term solution and plan to migrate to OAuth2 in XI for long‑term reliability and security.

For further support, visit the Nagios Support Forum or the Nagios Knowledgebase.