Caligare Flow Inspector

Caligare Flow Inspector analyzes NetFlow exports sent by existing routers, without requiring separate probes. Its web-based interface lets administrators configure collectors, network devices, application groups, and anomaly detection. The software provides real-time network analysis, user data tracking, and statistics on hosts, protocols, applications, and conversations. Caligare says this visibility can help identify suspicious activity, denial-of-service attacks, worm-infected stations, bottlenecks, and routing problems. The free edition supports NetFlow versions 1, 5, 6, 7, and 9, along with low-level traffic search, interface utilization maps, filtering, and forwarding. Authentication options include local, LDAP, or external methods, with user and group management. The free license is for non-commercial use and covers up to two devices, 24-hour history, and a maximum of 250 flows per second. Professional and Enterprise editions add longer historical trends, network anomaly detection, unrestricted NetFlow parsing, and commercial use. A 30-day trial license key can be requested by email. Linux packages are available, and the latest version requires MySQL 5.1 or newer.

Flow Inspector offers router-based traffic analysis with a free edition for small non-commercial setups and paid editions for commercial use. Check the free license limits and Linux database requirement before deployment.

Flow Inspector suits network administrators who need to analyze router-exported NetFlow data without deploying probes. The free edition is intended for non-commercial monitoring of up to two devices; commercial users can consider Professional or Enterprise editions.

Caligare Flow Inspector is a self-hosted NetFlow collector and analyzer that works with exports from routers already in place, so it does not require deployed probes. It is aimed at small non-commercial environments and commercial teams that need browser-managed traffic visibility. The free edition is genuinely usable for a two-device setup, while larger deployments and deeper historical analysis belong to the paid editions.

Overview

Flow Inspector turns router flow exports into a web-based view of network activity. Its real-time analysis, user tracking, and statistics for hosts, protocols, applications, and conversations are more useful for finding who is consuming capacity than a simple up-or-down monitoring check.

Caligare positions the software for several scales: non-commercial users can monitor up to two devices, businesses can cover one to nine devices, and enterprise deployments can use unlimited monitored devices. That makes the edition choice consequential rather than cosmetic. The product has been developed by a Prague-based company founded in 2004, and Caligare says it qualified for Cisco's Technology Developer Program and is distributed with a Cisco Compatible logo.

Key features

The browser interface configures collectors, network devices, application groups, and anomaly detection without requiring a separate desktop console. Flow Inspector can present top hosts, protocols, applications, and conversations, alongside interface utilization and utilization maps. Filtering, forwarding, and low-level traffic search give administrators ways to narrow an investigation instead of relying only on high-level charts.

The free edition accepts NetFlow versions 1, 5, 6, 7, and 9. It also includes local, LDAP, or external authentication plus user and group management, which is useful when several administrators need controlled access to the same collector.

Caligare says the analyzer can help expose suspicious activity, denial-of-service attacks, worm-infected stations, bottlenecks, and routing trouble. Those views can focus an investigation, but they should be treated as traffic-analysis signals rather than an automatic diagnosis of an incident.

Professional and Enterprise add longer-term historical trends, network anomaly detection, unrestricted NetFlow parsing, and commercial use. Those additions matter when a 24-hour snapshot cannot establish a baseline or support capacity planning, or when a business needs the license to cover production operations.

Pricing

Caligare Flow Inspector Free Edition — free. This is for non-commercial use, a maximum of two devices, 24-hour history, and a maximum of 250 flows per second. It is a sensible fit for a home lab, classroom, or very small non-commercial network. The device, history, and throughput ceilings make it unsuitable for a growing business or investigations that depend on weeks of context.

Caligare Flow Inspector Professional edition — custom pricing. Professional supports one to nine monitored devices and commercial use, while adding longer-term trends, anomaly detection, and unrestricted NetFlow parsing. It fits a small business that has outgrown the free edition but does not need unlimited device coverage.

Caligare Flow Inspector Enterprise edition — custom pricing. Enterprise is for commercial deployments with unlimited monitored devices. It is the appropriate tier for larger estates where a fixed device ceiling would force compromises, though buyers must request pricing.

A 30-day trial license key can be requested and is sent by email. One year of technical support for the free version can also be purchased online. The download requirements include a Linux distribution package and MySQL 5.1 or newer for the latest version, so deployment planning must include that database dependency.

Platforms

Flow Inspector runs on Linux as an on-premises, self-hosted deployment and is administered through the web. Caligare lists packages for Debian, RedHat, Fedora, SuSE, and other Linux distributions. It is a good match for organizations that control their own server environment; teams seeking a hosted service or a native mobile client should look elsewhere.

Who it's for

Choose Flow Inspector when router-exported NetFlow is already available and you want traffic, bandwidth, application, and conversation visibility without installing probes. Non-commercial users with two or fewer devices get the clearest value from the free edition. Small commercial networks should consider Professional, while enterprises needing unlimited device coverage and extended history belong on Enterprise.

It is less suitable when you need more than 24 hours of history without purchasing a commercial edition, exceed 250 flows per second on the free tier, or cannot operate Linux and MySQL on premises.

Pros and cons

Pros

• Uses existing router NetFlow exports, avoiding a separate probe deployment.
• Browser-based administration covers collectors, devices, application groups, and anomaly detection.
• Free edition includes five NetFlow versions, low-level search, utilization maps, filtering, forwarding, and multi-method authentication.
• Paid editions add longer historical trends, unrestricted parsing, anomaly detection, and commercial rights.

Cons

• The free edition is restricted to two devices, 24-hour history, non-commercial use, and 250 flows per second.
• Commercial Professional and Enterprise pricing requires a quote.
• Latest-version deployment requires Linux and MySQL 5.1 or newer.

Alternatives

Compare network traffic analysis software if you want a broader shortlist. ManageEngine NetFlow Analyzer is the stronger choice when you need Windows, Android, or iOS access alongside Linux and web, with a free two-interface edition and published monthly Standard and Professional plans.

Riverbed Aternity suits enterprises seeking a broader digital-experience-management offering across desktop, mobile, API, and self-hosted environments. SparrowIQ is worth choosing when a quoted subscription with defined throughput, concurrent-user, and historical-reporting allowances fits better.

ElastiFlow is a compelling alternative for Linux or self-hosted teams wanting a free tier with higher stated record throughput, SNMP-device coverage, dashboards, and machine-learning detections. FlowViewer is the simpler free Unix-server option, with paid hourly support and configuration services.

Nagios XI is better when node and service monitoring is the priority, while ntopng targets small networks and home practitioners with an open-source community edition. nfdump is the no-cost BSD-licensed alternative for Linux self-hosting without stated paid plans or usage limits.

Verdict

Caligare Flow Inspector is a strong fit for administrators who already export NetFlow from routers and want self-hosted, browser-based analysis without deploying probes. Its free edition is practical for up to two non-commercial devices; commercial users should choose Professional or Enterprise for licensing, longer history, and fewer parsing constraints. Look elsewhere if you need a hosted or cross-platform client, published commercial prices, or a free tier that scales beyond the stated device, history, and flow-rate limits.