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Networking · head to head

Nebula vs Zabbix

Nebula logo

Nebula

Networking

Certificate based overlay network from Slack, with identity and firewall rules carried in the certificate

From
Free
Rated
-
Full reviewWebsite
Zabbix logo

Zabbix

Networking

Open source infrastructure and network monitoring with distributed proxies and templating

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Nebula the open source project has no user interface, no enrolment workflow and no revocation service, so certificate issuing, distribution and expiry become scripts you write and then have to keep working.; Zabbix the database is the scaling limit, and high frequency polling grows history tables fast enough that untuned installations hit housekeeping stalls and query timeouts within months.
  • They diverge on capability: Nebula covers Certificate carried identity, Zabbix covers Agent and agentless collection.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Nebula and Zabbix actually diverge.

Attributes where Nebula and Zabbix differ
AttributeNebulaZabbix
PlatformsLinux, macOS, Windows, iOS, Android, FreeBSDLinux, Docker, Kubernetes, Web

Identical on both: starting price (Free), pricing model (Open source, no licence fee), free tier (Yes), user rating (Not yet rated), category (Networking).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Nebula

  • Certificate carried identity
  • Group based host firewall
  • Lighthouse discovery
  • Noise protocol encryption
  • Unsafe routes
  • Managed option

Only in Zabbix

  • Agent and agentless collection
  • Templates
  • Low-level discovery
  • Distributed proxies
  • Trigger expressions
  • Escalation actions

What people use each for

The jobs each tool is most often brought in to do.

Nebula

  • Flattening a network across several clouds and datacentres without VPC peering or route tablesnot Zabbix
  • Very large fleets where a central policy service on the connection path is unacceptablenot Zabbix
  • Environments that already run an internal certificate authority and want the network to use itnot Zabbix
  • Replacing per host iptables rules with policy written against roles that follow the hostnot Zabbix

Zabbix

  • A service provider monitoring thousands of customer devices where per-device commercial licensing is the largest line itemnot Nebula
  • Branch or industrial sites with unreliable links that need local collection and bufferingnot Nebula
  • Mixed estates where the same tool must poll SNMP switches, Linux hosts, Windows servers and Java applicationsnot Nebula
  • Replacing an aging Nagios installation while keeping script-based checks that already existnot Nebula

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Nebula

  • The open source project has no user interface, no enrolment workflow and no revocation service, so certificate issuing, distribution and expiry become scripts you write and then have to keep working.
  • Revoking a compromised host means distributing a blocklist entry to every other host and reloading them, which is a fleet wide operation rather than a click, and easy to get wrong under pressure.
  • Changing a host group membership means reissuing and redeploying its certificate, so policy changes are a deployment rather than a configuration edit.
  • There is no identity provider integration or single sign on in the open source version, so it maps well to servers and badly to a fleet of user laptops.
  • NAT traversal is best effort and hosts behind symmetric NAT need a relay configured deliberately, so connectivity failures show up as intermittent rather than immediate and are awkward to diagnose.

Zabbix

  • The database is the scaling limit, and high frequency polling grows history tables fast enough that untuned installations hit housekeeping stalls and query timeouts within months.
  • Initial configuration is heavy; getting useful alerting rather than noise requires understanding trigger expressions, macros and template inheritance, which is a multi-week learning curve for a team new to it.
  • The AGPLv3 change at version 7.0 affects anyone offering Zabbix over a network as part of a commercial service, and that obligation is easy to inherit accidentally during an upgrade.
  • The web interface is functional rather than pleasant, and many sites end up running Grafana alongside it purely for presentation, which is a second system to maintain.
  • Upgrades between major versions touch the database schema and can take hours on large history tables, so the maintenance window is proportional to how much data you kept.

Pricing, plan by plan

Nebula

Free
  • NebulaFree
    • Full functionality under the MIT licence
    • No host limit
    • You operate the certificate authority and lighthouses
  • Defined Networking$undefined/month
    • Hosted control plane and enrolment
    • Managed certificate lifecycle and revocation
    • Policy and DNS interface

Zabbix

Free
  • ZabbixFree
    • No device, node or metric limits
    • Full feature set with no paid edition of the software
    • AGPLv3 from version 7.0 onward
  • Zabbix Technical Support$undefined/year
    • Tiered subscriptions with defined response times
    • Access to Zabbix engineers for configuration and performance issues
    • Bug fix priority and backports

Which should you pick?

Choose Nebula if

  • You need certificate carried identity.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, iOS, Android, FreeBSD.
  • You also want group based host firewall.
Nebula review

Choose Zabbix if

  • You need agent and agentless collection.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Web.
  • You also want templates.
Zabbix review

Questions people ask

Is Nebula or Zabbix better?
Neither clearly leads. Nebula starts at Free and Zabbix at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Nebula or Zabbix?
Nebula starts at Free and Zabbix at Free.
Does Nebula or Zabbix run on more platforms?
Nebula runs on Linux, macOS, Windows, iOS, Android, FreeBSD. Zabbix runs on Linux, Docker, Kubernetes, Web.
Can I use Nebula for free?
Both have a free tier, so you can try either at no cost before committing.
What is Nebula best used for?
Nebula is most often used for flattening a network across several clouds and datacentres without vpc peering or route tables, very large fleets where a central policy service on the connection path is unacceptable, environments that already run an internal certificate authority and want the network to use it, replacing per host iptables rules with policy written against roles that follow the host. Of those, flattening a network across several clouds and datacentres without vpc peering or route tables and very large fleets where a central policy service on the connection path is unacceptable are not what Zabbix is typically brought in for.
What can Nebula do that Zabbix cannot?
Nebula covers Certificate carried identity, Group based host firewall, Lighthouse discovery, Noise protocol encryption. Zabbix covers Agent and agentless collection, Templates, Low-level discovery, Distributed proxies.

Answered from the vendors’ own pages

Nebula: Does it use WireGuard?

No. Nebula predates the common WireGuard mesh tools and uses the Noise protocol framework with its own certificate format.

Zabbix: Is Zabbix genuinely free for commercial use?

The software has no licence fee at any scale. From version 7.0 it is AGPLv3, so offering it as a network service to third parties carries source distribution obligations.

Nebula: Can I run it without Defined Networking?

Yes, entirely. Defined Networking sells the control plane conveniences, not the network itself.

Zabbix: What is the real cost of running it?

Database administration and the person who tunes it. Budget for PostgreSQL with TimescaleDB and someone who owns the retention policy.

Nebula: How do I revoke a host?

Add its certificate fingerprint to the blocklist in the configuration of the other hosts and reload them. There is no online revocation check.

Zabbix: How does it compare to a commercial per-device tool?

It removes the licence line entirely and adds an operations line. Below a few hundred devices the commercial tool is often cheaper in total; above that Zabbix wins clearly.

Nebula: Is it a good fit for laptops?

Less so than the identity provider based tools. There is no single sign on, so every laptop needs a certificate issued and renewed by whatever process you build.

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