Network discovery is the crucial first step for any IT team looking to manage a modern, dynamic network. As companies embrace flexible work options and adopt complex hybrid environments, taking stock of all connected devices is essential to maintain performance, ensure security, and enable users to stay productive from anywhere.
This article will cover everything you need to know about network discovery, from its core purpose to how it works to the tools that make it happen. Read on to learn why visibility is so valuable and how to unlock it in your own environment.
What is network discovery?
Network discovery refers to the process of identifying active devices on a network and collecting information about those devices. The goal is to create an accurate map of all endpoints that exist on your managed infrastructure.
A network discovery tool surveys networks using protocols like SNMP, CDP, and LLDP to find network devices like computers, printers, switches, routers, and access points and collect details like device type, IP addresses, hostnames, operating systems, opened ports and MAC addresses. This data is compiled into an inventory that provides complete visibility over all network-connected endpoints.
Network discovery serves several key functions:
- Asset inventory: Compile detailed lists of hardware and software assets deployed
- Security management: Detect rogue or unauthorized devices
- Change monitoring: Alert on network modifications and additions
- Capacity planning: Assess usage levels across links and hardware lifecycles
- Troubleshooting: Understand device roles and relationships impacting issues
With comprehensive information on all endpoints, you can effectively secure, monitor, and manage your infrastructure.
Types of devices discovered
Modern networks consist of a vast array of wired, wireless, and virtual assets that need to be managed and secured. Network discovery tools can identify and catalog details on all these components:
Wired devices:
- Servers: Physical and virtual servers running various operating systems, applications, and services. Discovery tools can classify server types and roles.
- Computers: Managed desktops, laptops, thin clients, and workstations for employee usage. Useful for tracking lifecycles and licensing.
- Printers: Networked printers, copiers, scanners, and multifunction printer/fax appliances present in office environments.
- IP phones: Desk phones, conference phones, and PBX equipment leveraging VoIP capabilities.
- Network gear: LAN hardware like routers, switches, controllers, firewalls and load balancers that enable connectivity.
Wireless devices:
- Laptops: Corporate assigned and BYOD employee laptops running wired or wireless. BYOD laptops may be running unsupported operating systems or unpatched versions, increasing security risks.
- Tablets: Company-owned and personal tablets (BYOD) utilizing Wi-Fi and cellular data. BYOD tablets connect to networks without IT oversight.
- Smartphones: Mobile phones connected over Wifi including BYOD devices that have unrestricted network access once onboarded.
- WAPs: Wireless access points providing Wi-Fi connectivity to endpoint devices like BYOD equipment with more limited visibility.
- IP cameras: Surveillance cameras transmitting video/images over wired and wireless networks.
Essentially any equipment with a network port or network interface that connects over TCP/IP can potentially be discovered. This encompasses IT, OT, IoT and mobile equipment types. Discovery tools scan infrastructures and build centralized repositories detailing all these assets.
There’s also the matter of the increasing number of people using their own devices. This influx of BYOD and mobile devices expands attack surfaces and hinders visibility as personal, unsupported equipment connects to production networks frequently outside of IT’s purview until a problem occurs.
With automated network discovery, you can classify and catalog full details on all BYOD devices to enable appropriate monitoring, access controls, and secure configurations.
Why network discovery matters
Network discovery is a critical process for a number of key reasons:
Visibility
Gaining visibility into your infrastructure is the most basic and essential benefit of network discovery. The old adage rings true – “you cannot manage what you cannot see.”
Discovery scans provide complete transparency and insight into devices, configurations, and software on a network. Without understanding what assets exist, it becomes almost impossible to secure, monitor, or troubleshoot a network effectively. Discovery enables management, while the improved visibility also helps improve relationships between IT and the end-user, resulting in a more productive and supportive environment.
Security
From a security perspective, network discovery helps identify rogue, unknown, or unauthorized devices on a network.
Malicious devices are growing threats that can attack internal resources or steal data. Identifying suspicious and anomalous endpoints not recognized as valid can allow security teams to lock down infrastructures against threats. Maintaining an updated list of approved hardware and software configurations allows more easily identifying Deviations that could present risks.
Manageability
On complex enterprise networks with a myriad of vendor hardware and software, understanding device hierarchies, interdependencies, and credentialing/access protocols is critical for smooth operations.
By mapping the relationships and communications between endpoints provided by network discovery, IT teams can more easily diagnose issues, restore failed links, and maintain productivity with insight into the ecosystem’s intricacies.
Planning
Network discovery provides invaluable data to feed capacity planning processes.
By reporting on usage across network links, age and status of hardware, lifecycle positions of equipment, and clustering of systems across locations/regions, technology leadership can plan budgets, schedules for maintenance events, and phases of expansion initiatives. Keeping plans aligned to actual infrastructure composition requires intelligent discovery capabilities.
Automation
With increasing reliance on automated IT processes around provisioning from bare metal or virtualized templates, auto-remediation of monitoring alarms, credential rotation, and software deployment, maintaining accurate discovery data is crucial.
Network configuration management databases (NCMDB) require the insights discovery provides to enable policy-driven automation.
Compliance
Many regulations and standards mandate cataloging hardware and software assets that interact with sensitive systems or data.
This includes frameworks like ISO 27001, NIST, NERC CIP, PCI DSS, HIPAA, and more. Discovery scans feed CMDBs and centralized reporting platforms to support audit processes ensuring compliance with these controls.
Managed service providers
For MSPs and network monitoring services relying on remote infrastructure management, network discovery provides a necessary baseline understanding of customer environments.
Discovery data better equips MSPs to manage incidents and identify upsell opportunities around hardware lifecycles. Information also facilitates more accurate quarterly business reviews.
How network discovery works
Network discovery tools rely on specialized protocols and technologies to identify and catalog devices on networks. Understanding these fundamental network discovery protocols is key for accurately mapping network environments.
What are network discovery protocols?
Network discovery protocols are networking communication standards that enable the automatic detection of devices on IP networks and facilitate the gathering of detailed information about those discovered assets. These protocols allow discovery tools to extract granular data from network components to map dependencies and relationships.
Most common network discovery protocols
Several common network protocols provide the foundation for mapping networked environments:
SNMP
Simple Network Management Protocol (SNMP) is the most dominant network discovery protocol.
SNMP offers a standardized way to monitor status and configurations across the myriad brands/models of routers, switches, servers, printers, UPS systems and other network gear found in enterprise IT environments.
SNMP works by leveraging distributed network agent software run on managed devices along with network management systems that act as clients, querying agents using get/set operations. Agents store device details in virtual databases called Management Information Bases (MIBs) that discovery tools can retrieve via SNMP for insights like model info, OS, serial numbers, interface speeds, and statistics.
CDP
Cisco Discovery Protocol (CDP) allows Cisco networking devices to advertise themselves to directly connected neighboring Cisco equipment for simpler management and asset tracking.
Information like device IDs, platform details, IP addressing, and software images allow for the creation of Cisco ecosystem maps. As a proprietary protocol, CDP discovery only works consistently between Cisco products and excludes third-party network hardware visibility. IT environments standardized on Cisco equipment can benefit but heterogeneous networks require supplemental protocols.
LLDP
Link Layer Discovery Protocol (LLDP) offers an open, standardized alternative to Cisco’s CDP.
LLDP allows visibility between adjacent endpoints from all hardware vendors by having Ethernet network devices, including switches, routers, WAPs, and firewalls, periodically transmit descriptive advertisements to peer devices over local network segments. These advertisements detail identifying information, capabilities, and configurations. which receiving LLDP agents store for discovery.
While similar functionally to CDP, LLDP’s cross-vendor operation and standards-based approach drive broader adoption for visibility across multi-vendor LAN/WAN equipment.
ARP
Address Resolution Protocol (ARP) provides the crucial mapping between IP addresses and physical MAC addresses of devices on local area networks (LANs).
This allows correlating and identifying devices by both properties, important as IP addresses can be dynamic while MAC IDs are fixed. Understanding both identifiers aids in discovery tracking.
Ping sweeps
Internet Control Message Protocol (ICMP) Echo Request messages, commonly referred to as pings, can be dispatched to ranges of IP addresses with tools recording which IPs respond positively, confirming active listening hosts. This presence detection through ping sweeps marks network endpoints for further interrogation via follow-on protocols.
Port scans
Checking TCP and UDP ports for open status indicates specific networking services associated with those well-defined port numbers running on discovered assets. For example, TCP port 80 or 443 indicates a web server while 22 signifies SSH. By cataloging opened ports, discovery tools can deduce server applications, roles, and functionality to create categorized infrastructure maps.
While these protocols enable discovery capabilities, it’s important to note that agent vs agentless monitoring approaches will affect how this data is collected and the depth of information available from network devices.
Security and privacy considerations
While network discovery tools provide administrative visibility that improves efficiency, security and compliance, the ability to inspect devices also introduces some risks that must be mitigated with proper planning:
Access controls
Stringent role-based access control ensures discovery capabilities don’t expose sensitive device configurations to unintended internal staff. Integrating network discovery tools with directory services helps manage permissions centrally.
Encryption
Network traffic containing discovery data should implement encryption both in transit and at rest to prevent interception or unauthorized access to sensitive details.
Network segmentation
It’s advisable to limit discovery capabilities to specific network zones rather than granting omniscient infrastructure-wide access. This helps limit exposure.
Change logging
Comprehensive activity logging ensures visibility into who accessed discovery data and when, facilitating audits.
Privacy controls
Configuring discovery tools to exclude gathering specific personally identifiable data can help address privacy concerns around employee devices and user details.
Following security best practices around access, data handling, and network architecture lets you safely maximize network visibility through discovery while protecting your environment.
What is network discovery software?
Network discovery software refers to programs that leverage protocols like SNMP, CDP, and Ping sweeps to find devices on networks and pull back details like type, operating system, opened ports, and configurations into a centralized database.
Discovery software runs on a dedicated appliance or server deployed onsite or from centralized cloud platforms to scan customer environments. Tools specialize in automatic asset tracking, visual network mapping, change management, and hardware lifecycle monitoring capabilities. Mature solutions integrate with other systems like ITSMs, CMDBs, and analytics tools to socialize the valuable inventory data.
Ideal network discovery software should include:
- Real-time scanning for immediate asset visibility
- Broad hardware, software, and virtual system detection
- Customizable reporting and alerting functionality
- Graphical network topology mapping
- User-friendly and intuitive interface designs
- Role-based access control for security
- API integration with complementary platforms
- Inventory data export to third-party databases
- Capability to handle large, complex networks
- Responsive and knowledgeable vendor support
Choosing the right network discovery product that aligns with your environment composition, use cases, budget, and commercial terms requires thorough evaluation.
How network discovery software works
Network discovery software works by utilizing various protocols and techniques to identify devices on the network and collect detailed information about them.
Here is a typical workflow:
Host discovery
The first step is to detect which IP addresses have active hosts. This is done by performing a ping sweep, sending ICMP echo request packets to a range of IP addresses, and recording which ones respond. This confirms the presence of a listening device.
Port scanning
For the responding hosts, the software conducts a port scan to see what TCP and UDP ports are open. Specific port numbers are associated with common services like HTTP, SSH, and FTP. This reveals operating systems and applications running on each host.
Service fingerprinting
With open ports discovered, the software can initiate connections to those services and analyze response banners for information like hostnames, OS versions, and application identifiers to further fingerprint the host.
Protocol interrogation
Protocols like SNMP, CDP, and LLDP are utilized to query network devices like routers, switches, and servers to pull descriptions, device types, configurations, and interfacing details.
Traffic analysis
By passively observing traffic flows, the discovery software can deduct certain host behaviors and relationships between source and destination devices, building out network dependencies.
Data compilation
The details extracted from all the above methods get compiled into a central database that serves as the source of truth for the inventory and topology of the managed infrastructure.
Presentation and alerting
Rich visualization dashboards present the discovered infrastructure in graphical network maps. Alerting and reporting provide oversight into the infrastructure to notify administrators of changes.
Additional techniques like network agents, virtual taps, and custom application fingerprints can also improve what network discovery tools can do.
But most network discovery tools today use the main methods listed above. These core technical capabilities allow modern network discovery tools to automatically find and catalog all the devices and connections in a network. This replaces manual discovery, which is very slow and limited.
With automated network discovery, organizations can quickly gain a complete view of their IT infrastructure without needing complex manual effort.
Top 3 types of network discovery tools
Network discovery solutions generally fall into three main categories:
Integrated infrastructure management platforms
These consolidate multiple IT management and monitoring capabilities into a single pane of glass.
Network discovery will be one module integrated with things like fault monitoring, performance tracking, configuration management, and analytics. This allows correlating inventory data with other metrics for enhanced troubleshooting and planning.
Dedicated network scanning tools
Tools here are purpose-built to provide network infrastructure snapshots through detailed asset scanning, port enumeration, service identification, vulnerability assessments, and reporting.
Integration APIs allow feeding data to broader systems. Scanning frequency and depth may be more limited than an integrated platform.
Cloud infrastructure monitoring providers
As infrastructure monitoring adopts cloud delivery models, these solutions combine remote network visualization capabilities with embedded network discovery features.
This leverages cloud convenience and accessibility while automating inventory tracking. Support and integrations may lag behind standalone on-premise alternatives.
Evaluate options across these categories based on your environment scale, use cases, supported protocols, and interfaces required to socialize the data collected by an automated network discovery engine within your infrastructure ecosystem.
Want to explore the top-recommended network discovery tools in more detail? Check out this comprehensive network discovery software roundup comparing the best products for accurate and automated asset visibility.
Next-level network management starts here
As networks grow exponentially more complex with new connected devices spanning IT, OT, IoT, and mobile users, gaining visibility through automated network discovery becomes essential. Expanded infrastructure introduces management blind spots that create operational and security risks.
Network discovery tools and broader monitoring systems provide the necessary functionality for mapping assets, their configurations, and interconnections. Core protocols like SNMP, CDP, and LLDP enable collecting device details.
Carefully evaluate vendor solutions based on critical capabilities around hardware/software support, data interfaces, scanning flexibility, and ease of use to meet your specific requirements.
Getting full value depends on selecting the ideal discovery platform, properly implementing organizational security policies and configurations when deploying the tools, and driving adoption through education on the benefits radically enhanced visibility provides.
With network discovery best practices in place, you gain simplified capacity planning, streamlined troubleshooting, proactive device life cycling, threat detection for cybersecurity – and ultimately more resilient, better-performing infrastructures.
Ready to experience the power of automated network discovery? Sign up for a free trial of Auvik to see how complete infrastructure visibility can transform your IT operations.
