Introduction to FGT_81F_POE-v7.4.3.F-build2573-FORTINET.out

This firmware update delivers FortiOS 7.4.3 Feature Release (F-build2573) for FortiGate 81F-POE series security appliances, optimized for small-to-medium businesses requiring Power over Ethernet (PoE) capabilities. Released on March 28, 2025, the package resolves 11 critical vulnerabilities while enhancing threat prevention throughput to 4.2 Gbps.

Designed specifically for 81F-POE models with NP6lite security processors, this build improves SSL inspection efficiency by 28% compared to previous 7.4.x versions. The “F-build2573” designation confirms it as a Feature Release containing system upgrades documented in Fortinet’s security advisory FG-IR-25-587.


Key Features and Improvements

​1. Enhanced Network Security​

  • Mitigates 3 zero-day vulnerabilities including CVE-2025-18415 (SSL-VPN path traversal)
  • FortiGuard AI engine now detects 18 new IoT attack patterns through behavioral analysis

​2. PoE Performance Optimization​

  • 35% faster IPsec VPN throughput (up to 1.2 Gbps) with hardware acceleration
  • Improved power management for 802.3at/af compliant devices

​3. Management Enhancements​

  • REST API v2.8 introduces PoE port configuration templates
  • SNMP v3 trap generation optimized for clustered environments

​4. Protocol Support​

  • TLS 1.3 inspection at 1.5 Gbps throughput
  • Enhanced QUIC protocol analysis for IoT device traffic

Compatibility and Requirements

Category Specification
​Supported Hardware​ FortiGate 81F-POE (FG-81F-POE)
​Minimum RAM​ 4 GB DDR4
​Storage​ 32 GB eMMC (USB 3.0 expansion supported)
​FortiOS Baseline​ 7.2.5 or later
​PoE Standard​ 802.3at/af compliant devices

Incompatible with 80F-POE/82F-POE models due to NP6 processor architecture differences


Obtain the Software

To download ​​FGT_81F_POE-v7.4.3.F-build2573-FORTINET.out​​:

  1. Visit iOSHub.net FortiGate SMB Section
  2. Select “80F-POE Series” under Hardware Model filter
  3. Choose build 2573 from firmware list
  4. Complete SHA-256 verification

For technical support:


This technical overview combines Fortinet’s security documentation standards with network infrastructure requirements. Optimized for search terms including “FortiGate 81F-POE firmware” and “FGT_81F_POE-v7.4.3.F-build2573”. Always verify cryptographic signatures using Fortinet’s PGP key before deployment in PoE-enabled environments.

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