10 Best SNMP Monitoring Tools in 2026 (Free and Paid)

The best SNMP monitoring tools in 2026 are PRTG Network Monitor for small and mid-size teams that want a quick Windows install, Zabbix and LibreNMS for teams that want free open source, ManageEngine OpManager and SolarWinds NPM for larger Windows-centric networks, Checkmk for mixed server and network estates, and Auvik, Domotz or Datadog if you prefer a cloud-managed service. All of them poll devices over SNMP v1, v2c and v3, receive SNMP traps, and graph interface bandwidth, CPU, memory and hardware health. The differences are price model, how much setup they need, and how well they handle SNMPv3 and custom MIBs at scale.

Every price below is vendor-published and was checked in September 2026. Where a vendor does not publish prices, we say so.

SNMP monitoring tools compared

Tool	Best for	Deployment	Free option	Paid pricing (vendor-published)
PRTG Network Monitor	SMBs wanting a fast install	Self-hosted (Windows)	Freeware, 100 sensors	From $200/month billed annually (500 sensors)
Zabbix	Free, large-scale SNMP	Self-hosted or Zabbix Cloud	Free, no device limits	$0; Cloud from $50/month
LibreNMS	Free SNMP auto-discovery	Self-hosted	Free, GPLv3	$0
ManageEngine OpManager	Mid-size Windows teams	Self-hosted	Free edition, 3 devices	From US$95/year (10 devices)
SolarWinds NPM	Large enterprises	Self-hosted or SaaS	30-day trial	Observability Self-Hosted from $8/node/month (multi-year, billed annually); NPM standalone quote-only
Checkmk	Mixed server and network estates	Self-hosted or SaaS	Community edition free	Pro from €190/month billed annually (shown in EUR)
Nagios XI	Nagios plugin users	Self-hosted	Free up to 7 nodes	From $2,595 (Standard, 100 nodes)
WhatsUp Gold	On-prem Windows shops	Self-hosted (Windows)	Free edition, 10 devices	From $1,229/year for 50 devices
Datadog Network Device Monitoring	Teams already on Datadog	SaaS	14-day trial	$7/device/month billed annually
Domotz	MSPs and multi-site	SaaS with site collector	14-day trial	$35/site/month

What is SNMP monitoring?

SNMP (Simple Network Management Protocol) is the standard way network devices report their health. Almost every managed switch, router, firewall, wireless controller, UPS, printer and storage array ships with an SNMP agent. A monitoring tool, acting as the SNMP manager, asks that agent for values on a schedule (polling), and the agent can also push alerts on its own (traps or informs).

Each value lives at an OID (object identifier) defined in a MIB (management information base). Standard MIBs such as IF-MIB cover interfaces on every vendor’s kit; vendor MIBs add model-specific data such as fan speeds, PSU status or Wi-Fi client counts. A good SNMP tool ships with templates for common devices and lets you import extra MIBs when it does not recognise something.

• Polling: the manager sends GET or GETBULK requests to the agent on UDP port 161, typically every 1 to 5 minutes.
• Traps and informs: the agent sends an unsolicited message to the manager on UDP port 162 when something happens, such as a link going down. Informs are acknowledged; traps are not.

SNMP v1 vs v2c vs v3: which should you use?

Version	Defined in	Authentication	Encryption	64-bit counters	Use it?
SNMPv1	RFC 1157 (now Historic)	Plain-text community string	None	No	Only for very old devices
SNMPv2c	RFC 1901 (Experimental)	Plain-text community string	None	Yes (Counter64)	Acceptable on an isolated management network
SNMPv3	RFC 3411 to 3418 (Internet Standard)	Per-user (User-based Security Model, RFC 3414)	Yes, optional	Yes	Default choice for anything new

The IETF’s own overview (RFC 3410) is blunt about the older versions: v1 and v2c “support only trivial authentication based on plain-text community strings and, as a result, are fundamentally insecure.” Anyone who can sniff your management traffic can read the community string. SNMPv3 fixes this with per-user authentication and optional encryption, using three security levels: noAuthNoPriv, authNoPriv and authPriv. Use authPriv with SHA-based authentication and AES privacy wherever the device supports it.

v2c still matters for one reason: it introduced 64-bit counters. On a 1 Gbps or faster interface, the old 32-bit octet counters can wrap between polls and produce nonsense bandwidth graphs. Make sure your tool reads ifHCInOctets and ifHCOutOctets (the 64-bit versions) on fast links.

What can be monitored with SNMP?

• Interfaces: up/down status, bandwidth in and out, errors, discards, speed and duplex.
• Device health: CPU, memory, temperature, fans, power supplies, uptime.
• Wireless: access point status and connected clients (vendor MIBs).
• Servers and storage: disk usage, RAID status and running processes through host MIBs.
• Power and environment: UPS battery level, load and runtime; PDU current; rack temperature and humidity sensors.
• Printers: toner and paper levels, error states.

What SNMP cannot tell you is who is using the bandwidth. For that you need flow data (NetFlow, sFlow or IPFIX); see our guide to network traffic and bandwidth monitoring tools. For the bigger picture of how SNMP fits alongside flows, packet capture and synthetic tests, read what is network monitoring.

The best SNMP monitoring tools in 2026

1. PRTG Network Monitor: best for small and mid-size teams

PRTG supports SNMP v1, v2c and v3, auto-discovers devices and applies SNMP sensors for traffic, CPU, memory and hardware health, with SNMP Custom sensors for other OIDs and an SNMP Trap Receiver sensor that filters and analyses incoming traps. Setup on a Windows server takes minutes, which is its main advantage over open-source options.

• Pricing (vendor-published, checked September 2026): subscription from $200/month (500 sensors) to $1,642/month (10,000 sensors), paid annually. One sensor is one metric, and Paessler estimates about 10 per device.
• Free: Freeware Edition up to 100 sensors; 30-day unlimited trial.

2. Zabbix: best free SNMP monitor at scale

Zabbix supports SNMP v1, v2c and v3 and trap collection, uses low-level discovery to find interfaces automatically, and ships vendor templates for most switches and routers. Proxies spread polling across sites. The trade-off is time: templates, triggers and SNMPv3 credentials all need care. 7.0 is the current long-term-support release.

• Pricing (vendor-published, checked September 2026): free with no device limits. Zabbix Cloud (hosted) starts at $50/month; paid support is quote-only.
• Watch out for: no native flow analysis.

3. LibreNMS: best free auto-discovery

LibreNMS is a community, GPLv3-licensed, PHP/MySQL network monitor built around SNMP. It auto-discovers neighbouring devices using CDP, FDP, LLDP, OSPF, BGP, SNMP and ARP, which makes it quick to cover a large multi-vendor network once installed.

• Pricing: free and open source; community support.
• Best for: network teams comfortable running a Linux server who want SNMP graphs for every port with little manual setup.

4. ManageEngine OpManager: best value commercial option

OpManager licenses per device (every interface on a device is included) and covers SNMP polling, traps, custom MIBs and hardware health. ManageEngine also offers free SNMP utilities: OpUtils‘ free edition includes a MIB browser, SNMP walker, trap receiver and community checker, useful for testing devices before you monitor them.

• Pricing (vendor-published, checked September 2026): annual subscription from US$95 for 10 devices (Standard) or US$145 (Professional); 100 devices cost US$795 (Standard). Enterprise from US$4,595 for 250 devices.
• Free: Free Edition for up to 3 devices; 30-day trial.

5. SolarWinds Network Performance Monitor: best for large enterprises

SolarWinds NPM discovers SNMP-enabled routers, switches, firewalls and wireless controllers and adds hop-by-hop path analysis and topology maps. It is now positioned as part of SolarWinds Observability Self-Hosted, with a SaaS sibling, SolarWinds Observability.

• Pricing (vendor-published, checked September 2026): Observability Self-Hosted starts at $8 per node per month (Essentials); SaaS network and infrastructure monitoring starts at $15.75 per node per month. Both are on multi-year contracts billed annually. Standalone NPM is quote-only.
• Free: 30-day trial.

6. Checkmk: best for mixed server and network estates

Checkmk supports SNMP v1, v2c and v3 and discovers the services on each device automatically, so switches, servers and applications land in one view with sensible defaults. Editions are Checkmk Community (formerly Raw, free and open source), Pro, Ultimate and the hosted Checkmk Cloud.

• Pricing (vendor-published, checked September 2026): priced per monitored service. The pricing page showed euros for us: Pro from €190 per month and Ultimate from €275 per month billed annually for about 3,000 services. Check the site in your own currency.
• Free: Community edition; 30-day trials of paid editions.

7. Nagios XI: best if you already use Nagios plugins

Nagios XI polls SNMP and receives traps, with wizards that set up switch and router checks. Nagios Core, the free engine underneath, can do the same with more manual configuration.

• Pricing (vendor-published, checked September 2026): Standard from $2,595 for 100 nodes, including the first year of maintenance and support.
• Free: Nagios Core is free; XI’s free version covers 7 nodes or 100 services.

8. WhatsUp Gold: best on-premises option for Windows shops

Progress WhatsUp Gold monitors with SNMP v1 to v3, SSHv2 and WMI, draws interactive topology maps, and adds traffic analysis through its NTA+ module.

• Pricing (vendor-published, checked September 2026): per year for 50 devices: Business from $1,229, Enterprise from $2,049, Enterprise Plus from $3,469.
• Free: Free Edition for up to 10 devices.

9. Datadog Network Device Monitoring: best for cloud-first teams

Datadog collects SNMP metrics and SNMP traps from network devices alongside its infrastructure and application monitoring, so network and server problems appear on one timeline.

• Pricing (vendor-published, checked September 2026): $7 per device per month billed annually, or $8.50 month-to-month.
• Free: 14-day trial.

10. Domotz: best for MSPs and many small sites

Domotz places a lightweight collector on each site, discovers every device, and lets you “monitor any SNMP (v1/v2/v3) OID values and set thresholds for alerting”, in the vendor’s words. It also maps topology and backs up switch, firewall and access point configurations.

• Pricing (vendor-published, checked September 2026): $35 per site per month, or $17.50 with a 12-month commitment (MSP plan); unlimited devices.
• Free: 14-day trial.

Other capable SNMP tools include Auvik (SaaS, quote-only), OpenNMS and Observium.

Is there a free tool for monitoring SNMP devices?

Yes. Zabbix, LibreNMS, Nagios Core and Checkmk Community are free and open source with no device limits. Cacti (GPL) graphs SNMP counters using RRDtool. Among commercial tools, PRTG Freeware covers 100 sensors, WhatsUp Gold Free Edition covers 10 devices, OpManager Free Edition covers 3 devices, and ManageEngine OpUtils’ free edition bundles SNMP diagnostic tools such as a MIB browser, SNMP walker and trap receiver.

How to choose an SNMP monitoring tool

• Check SNMPv3 support in practice, not just on the datasheet: bulk credential assignment, SHA-2 and AES-256 options, and per-device overrides save hours.
• Test your oddest device first. Import its vendor MIB during the trial and confirm the tool can graph the OIDs you care about.
• Look at the licensing unit. PRTG counts sensors (one per metric), Datadog counts devices, Domotz counts sites. Model your real estate before comparing prices.
• Trap handling: can the tool translate, de-duplicate and correlate traps, or does it just list them?
• Scale: for more than a few hundred devices or multiple sites, confirm the tool supports remote pollers or collectors.

For a broader comparison that covers flow analysis, synthetic monitoring and cloud options, see our guide to the best network monitoring software, or browse the network monitoring software category.

Frequently asked questions