# Fabric OS

In storage area networking, Fabric OS (FOS) is the firmware for Brocade Communications Systems's Fibre Channel switches and Fibre Channel directors.

## First generation

The first generation of Fabric OS was developed on top of a VxWorks kernel and was mainly used in the Brocade Silkworm 2000 and first 3000 series on Intel i960.

## Second generation

The second generation of Fabric OS (4.0) was developed on a PowerPC platform, and uses MontaVista Linux, a Linux derivative with real-time performance enhancements. With the advent of MontaVista, switches and directors have the ability of hot firmware activation (without downtime for Fibre Channel fabric), and many useful diagnostic commands.
According to free software licenses terms, Brocade provides access to sources of distributed free software, on which Fabric OS and other Brocade's software products are based.

## Additional licensed products

Additional products for Fabric OS are offered by Brocade for one-time fee. They are licensed for use in a single specific switch (license key is coupled with device's serial number). Those include:
* Integrated Routing
* Adaptive Networking: Quality of service, Ingress Rate Limiting
* Brocade Advanced Zoning (Free with rel 6.1.x)
* ISL trunking
* Ports on Demand
* Extended Fabrics (more than 10 km of switched fabric connectivity, up to 3000 km)
* Advanced Performance Monitoring (APM)
* Fabric Watch
* Secure Fabric OS (obsolete)
* VMWare VSPEX integration

## Versions

Fabric OS current "Posted" versions :
| Major Version (Date) | Version | Date | Target Path | FICON Qualified | Posting Status | Notes |
| Current stable version: 9.2.2x (October 2024) | 9.2.2 | October 15, 2024 | No | No | Posted | |
| Old version, yet still maintained: 9.2.1x (December 2023) | 9.2.1b | January 7, 2025 | No | No | Posted | |
| Old version, yet still maintained: 9.2.1x (December 2023) | 9.2.1a1 | October 31, 2024 | No | Yes | Posted | |
| Old version, yet still maintained: 9.2.1x (December 2023) | 9.2.1 | December 20, 2023 | No | No | Posted | |
| Old version, yet still maintained: 9.2.0x (April 2023) | 9.2.0c3 | January 22, 2025 | Yes | Yes | Posted (LW) | |
| Old version, yet still maintained: 9.2.0x (April 2023) | 9.2.0b1 | June 27, 2024 | Yes | Yes | Posted | |
| Old version, yet still maintained: 9.1.x (December 2021) | 9.1.1d2 | July 11, 2024 | Yes | Yes | Posted (LW) | |
| Old version, yet still maintained: 9.1.x (December 2021) | 9.1.1c3 | November 9, 2023 | Yes | Yes | Posted | |
| Old version, yet still maintained: 8.2.x (November 2017) | 8.2.3e2 | December 17, 2024 | Yes | Yes | Posted | Available and supported for Gen 5 platforms only |
| Legend:Old version, not maintainedOld version, still maintainedLatest versionLatest preview versionFuture release LW = Lifetime Warranty platforms |||||||
* Fabric OS 9.x
** 9.2.2:
** 9.2.1:
** 9.2.0:
** 9.1: Root Access Removal, NTP Server authentication
** 9.0: Traffic optimizer, Fabric congestion notification, New Web Tools (graphical UI switched from Java to Web)
* Fabric OS 8.x
** 8.2: NVMe capable + REST API
** 8.1:
** 8.0: Contains many new software features and enhancements as well as issue resolutions
* Fabric OS 7.x
** 7.4: Switch to Linux 3.10 kernel
** 7.3:
** 7.2:
** 7.1:
** 7.0:
* Fabric OS 6.x
** 6.4:
** 6.3: Fillwords 2 and 3 introduced in Fabric OS 6.3.1a
** 6.2: Virtual Fabrics-capable
** 6.1: M-EOS compatibility enhancements
** 6.0: LDAP support
* Fabric OS 5.x
** 5.3: Switch to Linux 2.6 kernel
** 5.2:
** 5.1: Access Gateway mode
** 5.0:
* Fabric OS 4.x
** 4.4:
** 4.3:
** 4.2:
** 4.1: SSH support, Multiple user access
** 4.0: migrated from VxWorks to Linux
* Fabric OS 3.x
* Fabric OS 2.x