Overview

Nagios XI evaluates configured thresholds, records results, and sends notifications across infrastructure. Its hybrid approach, agentless monitoring, server auto-discovery, and support for process and container monitoring make it relevant to teams overseeing mixed environments. Monitoring servers, network devices, applications, and services in one system gives administrators breadth, but teams wanting a hosted service should look elsewhere: XI is deployed on Linux infrastructure they operate.

The license counts monitored Nodes rather than Services, with no Services cap per licensed Node. A single license key can cover production, test or lab, and disaster recovery installations under the stated operating conditions. This is useful for teams maintaining multiple environments, though it does not remove the work of managing the self-hosted deployment.

Key features

Standard includes 90+ Configuration Wizards, Auto-Discovery, dashboards, performance graphs, an open REST API, automation, configuration rollback, and snapshots. Together, these give administrators several ways to configure monitoring and manage changes, while the API and automation can support integration with existing workflows.

Enterprise adds SLA reports, Capacity Planning, scheduled reports and pages, Business Process Intelligence, bulk modification tools, and an Audit Log. Those additions make the higher tier a better fit for teams that need reporting and operational oversight beyond core monitoring; teams that only need the Standard toolset need not pay for them.

Authentication options include Active Directory or LDAP over SSL, Microsoft Entra ID single sign-on, and Duo two-factor authentication. Access can be limited by Host and Service groups, which helps align visibility with team responsibilities.

Pricing

The Free plan costs 0.00 USD per free and is self-supported. It includes most Standard features but caps monitoring at 7 Nodes or 100 Services, whichever comes first. That ceiling makes it suitable for a small evaluation or limited deployment, not a growing estate.

Standard costs 2595.00 USD per once for the 100 Nodes price point. It includes 100 Nodes, unlimited Services, and the first year of Maintenance & Support. It is the lower-cost paid fit for teams that need the core feature set and can do without Enterprise reporting and management tools.

Enterprise costs 4690.00 USD per once at the 100 Nodes price point, with 100 Nodes, unlimited Services, and Enterprise features. A paid license also includes the first year of Maintenance & Support, version upgrades, up to ten support cases, Support Portal access, Premium features, and an assigned Customer Success Manager. The perpetual model avoids a recurring license term, but the upfront purchase is a substantial commitment.

Sitewide has custom pricing and includes multiple installations, unlimited Nodes, Enterprise features, and a Nagios Fusion license. It is aimed at organizations that need broader deployment than the 100-Node tiers provide.

The 30-day trial includes unlimited monitoring, Enterprise features, and direct technical support, with no credit card required. It offers room to assess the full feature set before choosing a tier.

Platforms

Nagios XI is self-hosted on Linux. Virtual machine images are available for VMware Workstation, Oracle VirtualBox, VMware ESXi and vSphere, and Microsoft Hyper-V. Offline installation is supported on Red Hat and CentOS Stream with dependencies included in the installer, a practical option for restricted networks.

The monitored operating systems include Linux, Windows, macOS, AIX, and Solaris. The listed platform coverage should not be confused with server deployment: the XI server itself runs on Linux.

Who it's for

Nagios XI is a strong fit for infrastructure teams that want control over deployment, broad host and service monitoring, and the flexibility to monitor unlimited Services per paid Node. Its Linux requirement and self-hosted operating model suit teams with the capacity to maintain their own monitoring server. The Free plan can serve a small environment, while the paid tiers are more appropriate once its Node or Service cap becomes restrictive.

It is a weaker fit for teams seeking a managed cloud service or a low-commitment paid entry point. The free tier is tightly capped, and paid licenses are perpetual purchases priced by Node.

Pros and cons

Pro: Paid licenses allow unlimited Services per Node, so service count does not add a separate cap within the licensed Node allocation.
Pro: One license key can cover production, test or lab, and disaster recovery installations under the stated operating conditions.
Pro: Enterprise combines SLA reports, Capacity Planning, scheduled reporting, Business Process Intelligence, bulk changes, and an Audit Log for teams with more demanding oversight needs.
Pro: The trial provides unlimited monitoring, Enterprise features, and direct technical support for 30 days without requiring a credit card.
Con: The Free plan stops at 7 Nodes or 100 Services, whichever comes first, limiting its usefulness beyond small deployments.
Con: The server must be self-hosted on Linux, so teams avoid neither deployment nor operational responsibility.
Con: Standard and Enterprise require substantial perpetual payments, and the included Maintenance & Support covers the first year.

Alternatives

For a different take on network traffic analysis, compare Network Traffic Analysis Software and Bandwidth Monitoring Software. For broader infrastructure and cloud coverage, see Infrastructure Monitoring and Cloud Monitoring; Hardware Monitoring Software and Metrics Monitoring Tools offer additional category comparisons.

ElastiFlow is worth considering when a free network-focused option is preferable: its Basic plan is free and includes up to 4,000 records per second, up to 25 SNMP devices, 40+ dashboards, 120+ ML detections, and Slack and Forum support.

ntopng offers a free Community (Open Source) edition designed for home and network practitioners, with a suggested maximum of 256 live local hosts. Akvorado is another free option, developed by Free, a French ISP.

Riverbed Aternity is an enterprise alternative with pricing not stated publicly. Intermapper offers custom-quote subscription or perpetual licensing on a device basis, with options starting at 10 devices.

Kentik Network Monitoring System is a web-based alternative with a 30-day trial and a Pro plan starting at $2,000 per month, billed annually, for 50 users and 120 days of traffic visibility. Noction Flow Analyzer offers Linux self-hosted options, including a $299 monthly NFA license and an optional $199 monthly BGP add-on. Andrisoft Wansight has a $345.00 per year sensor license for one Packet Sensor or one Flow Sensor, limited to monitoring.

Verdict

Choose Nagios XI if your team wants broad, configurable infrastructure monitoring, needs unlimited Services per paid Node, and can operate a Linux-hosted system. The perpetual licensing and multi-installation allowance give it practical flexibility, while Enterprise adds useful reporting and oversight. Look elsewhere if self-hosting is a mismatch or if the Free tier's low cap and paid tiers' upfront cost do not suit your scale or budget.

	Nagios XI	SolarWinds Observability
Free plan	Yes	No
Free trial	Yes	Yes
Paid from	Free	$5/mo
Open source	No	No
Platforms	api, Linux, self-hosted, Web	api, Linux, self-hosted, Web, Windows
Free plan	Yes	No
Paid from	—	5 /mo

Nagios XI vs SolarWinds Observability

Nagios XI

SolarWinds Observability