Documenting Your Network
A description of how your network is actually put together — topology, addressing, grouping and dependencies — assembled by the monitoring rather than maintained by hand.
Network documentation has a habit of being accurate on the day it is written and slowly false afterwards. The diagram lives in one place, the address plan in another, and the person who knew why a link was there has moved on.
NetCrunch approaches this from the other end. To monitor a network it has to discover how that network is arranged, and that understanding is kept, drawn and updated as a side effect of monitoring. What you get is a description of the network as it is now, not as someone last recorded it.
This is the companion to NetCrunch as an Inventory Database. Inventory answers what each thing is — hardware, software, versions. This answers how the things are arranged — what connects to what, what sits where, and what depends on what.
nd-topology
The Map Draws Itself
Two layers of topology are discovered and maintained without anyone drawing them:
- Routing maps
- The logical picture — which IP networks exist and which routers join them.
- Physical connection maps
- The layer 2 picture — which device is plugged into which switch port, with a per-switch view showing the traffic on each port.
Both are covered in Network Topology Maps, including how to enable physical segment monitoring and what to do when a device is missing from a map.
nd-organization
The Organization Is Discovered Too
Beyond the wiring, the atlas records how the estate is divided up — and most of those divisions maintain themselves from monitored data rather than from a list somebody edits:
- Device Groups and Server Types — printers, switches, wireless, Linux, Windows Server
- Locations — from SNMP location data or entered by hand
- VLANs and Windows Domains
- Organizations, for estates serving more than one
- Virtual Machine Hosts, with their guests beneath them
These are dynamic views: a node that changes role moves group on its own. See Network Atlas Views.
Where the Same Address Means Two Different Places
Estates that run the same private range in more than one location are exactly where hand-kept documentation falls apart. NetCrunch handles it with network sites — separate address spaces, so 192.168.1.10 in one branch is not confused with 192.168.1.10 in another. The site is part of how a node is identified rather than an annotation on it.
nd-dependencies
What Depends on What
The most useful thing about a network description is usually not the list of parts — it is knowing what goes dark when one of them fails.
NetCrunch records dependencies from what it already knows: the route to a node, the virtualization host underneath it, and the layer 2 connections it discovered. That is what lets it report the failed router rather than the two hundred nodes behind it.
Where the dependency is a business one rather than a network one, you describe it yourself with a composite status, and NetCrunch draws the result. See Composite Status and Business Service Views.
nd-your-knowledge
The Part Only You Know
Discovery cannot find who owns a server, which contract covers it, or why a link exists. Two features hold that:
- Custom fields
- Number, text, date, time or pick list, added to the node record. Because views can filter on them, "everything owned by Finance" becomes a view that maintains itself. See Managing Node Custom Data.
- Notes
- Free text against a node, for the reasoning that does not fit a field.
Device classification sits between the two — mostly discovered, correctable by hand, and worth correcting because so much else follows from it. See Device Identification Manager.
nd-boundaries
What This Does Not Cover
- It documents what it monitors. Anything NetCrunch has never seen is not described, so coverage of the documentation is coverage of the monitoring.
- It records what is, not what was intended. The maps show the network as discovered. A link that should not be there is drawn exactly like one that should.
- It is not a design tool. There is no planned-state diagram to compare the discovered one against.
- Architecture and Concepts
Overview of NetCrunch Server architecture. Learn more about Monitoring Engines, NetCrunch Consoles, databases, additional tools, and critical concepts of advanced network visualization.
- NetCrunch as an Inventory Database
NetCrunch is an inventory database as well as a monitoring system. Everything it monitors, it also records — hardware, installed software, hotfixes and your own asset data — and because it keeps looking, it tells you when any of it changes.
- End-of-Life Monitoring
NetCrunch tracks when the operating systems it monitors stop being supported, alerts a chosen number of months ahead, and shows the state of every Windows and ESXi host in one grid.
- Network Atlas Views
Read about types of views and how they organize your data.
- Windows Configuration - Hardware, Software, Hotfixes
The sensor allows monitoring of the hardware configuration of Windows machines using WMI.
- Network Topology Maps
NetCrunch automatically builds network topology maps to visually represent logical routing and physical Layer 2 connections between network devices. These maps aid in understanding network structure, monitoring connectivity, and troubleshooting problems.
- Node Status Overview – Real-Time Monitoring & Context
The Node Status window in NetCrunch provides a comprehensive, real-time view of a monitored node’s condition. It includes monitoring status, performance metrics, activity logs, system properties, dependencies, alerts, and more. For Windows, Linux, hypervisors, and network devices, NetCrunch presents unmatched visibility in a unified interactive interface.
- NetCrunch Databases
NetCrunch uses several specialized databases to efficiently manage configuration, event history, real-time status, long-term metrics, and documentation. Each database is optimized for its specific role in the monitoring platform, allowing NetCrunch to scale from hundreds to thousands of nodes while ensuring high performance.
- Update, Migrate and Backup
Learn how to perform NetCrunch updates, migrate it to other machines, or set up a backup.
- Atlas Configuration Upgrade
An atlas created in an older version keeps the predefined monitoring packs and views it was born with. The upgrade brings those up to the current release without touching anything you configured yourself.
- When the Atlas Cannot Be Loaded
If NetCrunch cannot open the atlas at startup it does not simply fail. It offers three recovery options in order of how much you stand to lose: open it again, restore it from a backup, or delete it and start over.
- Glossary of Terms
Definitions of the terms used throughout this guide - alert, event, site, composite status, atlas node view and the rest.
- - Atlas View Settings
- Adding Targets to Monitoring
This topic provides instructions for adding monitoring targets to NetCrunch, including nodes, sensors, and data collectors. It covers configuring network services, operating systems, SNMP, virtualization platforms, and setting up alerting rules and dependencies. Additionally, it guides users on adding new nodes and using monitoring templates for efficient management.