ferm
ferm: A structured, reusable way to manage iptables rules on Linux. Ranked #66 of 76 in Firewall Software by our editors (3.0/10); pricing: Open source; best for linux teams managing reusable iptables configurations.
At a glance
- Editor score3.0 / 10
- PricingOpen source
- Best forLinux teams managing reusable iptables configurations
- Paid fromFree
- Outbound controlAdvanced
- Facts checked22 Sep 2026
Where it wins
- Structured files support variables, functions, arrays, blocks, and includes
- IPv4/IPv6 domains plus interactive rollback support safer rule changes
- Imports existing rules and generates rules remotely or as shell scripts
Where it doesn't
- Requires Linux, iptables, Perl, and a netfilter-enabled kernel
- Works as a configuration layer rather than a complete firewall platform
- Its scope stays closely tied to iptables and related command-line tools
Our verdict on ferm
ferm is an open-source configuration frontend for Linux iptables firewall rules. It reads structured configuration files and converts them into rules inserted into the running kernel. The tool is aimed at firewall administrators and Linux teams that need readable, maintainable, reusable rulesets while retaining the flexibility of standard iptables matches and targets. Its configuration language includes variables, functions, arrays, blocks, included files, and separate IPv4 and IPv6 firewall domains.
The main strength is configuration depth. Included files support reuse, while interactive rule application can apply an automatic rollback timeout, giving administrators a defined recovery path during changes. ferm also supports fast ruleset installation through iptables-save and iptables-restore, imports existing iptables-save rules with import-ferm, and can generate rules remotely or output shell scripts. These capabilities make it suited to teams standardizing firewall configurations across Linux systems without abandoning iptables syntax and behavior.
The product is open source and integrates directly with iptables, iptables-save, iptables-restore, netfilter, and Perl. That ecosystem fit is also its boundary: ferm requires Linux, iptables, Perl, and a kernel with netfilter support, and it remains a configuration layer rather than a complete firewall platform. Choose ferm when structured, reusable files and controlled iptables administration are the priority. Teams seeking a broader firewall product beyond the Linux iptables stack should consider an alternative with a wider platform scope.
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ferm pricing
ferm fact sheet
| Free plan | Not verified |
|---|---|
| Paid from | Free |
| Outbound control | Advanced |
| Rule direction | Both |
| Connection alerts | Not verified |
| Application rules | Not verified |
| Supported platforms | linux |
| Central management | Not verified |
| Deployment | Self-hosted |
| Platforms | Linux |
| Support | Community, Docs |
| Built for | Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 5 integrations: iptables, iptables-save, iptables-restore, netfilter, Perl |
| Pricing | Open source |
| Website | github.com |
| Facts checked | 22 Sep 2026 |
ferm integrations
ferm lists 5 integrations on its own site.
- iptables
- iptables-save
- iptables-restore
- netfilter
- Perl
Alternatives to ferm
- FortiGateA broad hybrid firewall platform for organizations that need deep security and network controls.9.4
- Arista NG FirewallA broad firewall platform with a free plan and extensive network controls.9.3
- Google Cloud NGFWGoogle Cloud-native firewall protection with free rule evaluation and usage-priced advanced controls.9.2
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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