What is the ICF file format?
.icf files are configuration backup files used by Zoom Telephonics routers and modems. They store device settings in a plain-text, INI-style format consisting of key=value pairs that describe the network configuration of the device.
A typical .icf backup file may contain:
- WAN and LAN IP address settings,
- DHCP server configuration,
- PPPoE or DSL credentials,
- firewall rules and port forwarding entries,
- DNS server assignments,
- wireless SSID and security key settings.
The file is generated through the router's web management interface as a backup and can be restored to the same or a compatible device to replicate its configuration. Because the format is device-specific and not publicly standardized, the exact key structure varies across Zoom Telephonics firmware versions.
Zoom Telephonics was later acquired by PCTEL; the ICF format receives no active development. The .icf extension is also associated with several unrelated legacy applications: the defunct Cheyenne AntiVirus (a Windows 95-era product acquired by Computer Associates in 1996), BEA Tuxedo Java EE server configuration, and Geomagic 3D CAD software. On modern systems it is most commonly encountered as a Zoom router backup.
Any plain-text editor - such as Notepad, nano, or TextEdit - can open an .icf file, though the router's web interface is the recommended way to manage device settings.
Security & safety
RISK: LOWPlain text configuration file; no executable code. Restoring a tampered ICF to a router could alter network/firewall settings - verify the file source before using it in a router admin panel.
Format details
in a nutshell- Cheyenne AntiVirus Data File - Legacy Windows 95-era antivirus internal data/config file; Cheyenne Software acquired by CA 1996, product discontinued.
- BEA Tuxedo ICF (Interface Configuration File) - Configuration file for BEA/Oracle Tuxedo middleware describing service interfaces.
- Geomagic Verify ICF - 3D inspection software configuration/result file by 3D Systems.
Programs that open ICF files
Windows1 app
macOS1 app
Linux1 app
Technical details
deep spec| Developer | Zoom Telephonics (subsequently acquired by PCTEL) |
| File type | Plain-text network device configuration backup |
| Encoding | ASCII or Latin-1 |
| Format structure | INI-style key=value pairs; exact structure varies across Zoom Telephonics firmware versions |
| Typical file size | 1 KB - 50 KB |
| Stored settings | WAN/LAN IP addresses, DHCP config, PPPoE credentials, firewall rules, port forwarding, DNS, Wi-Fi SSID and security key |
| Generated by | Router or modem web management interface (backup/export function) |
| Restoration | Uploaded via the device's web interface to restore previously saved settings |
| Platform | Any OS with a web browser; configuration file downloaded via HTTP from the router |
| Extension conflicts | `.icf` also used by defunct Cheyenne AntiVirus (Windows 95-era), BEA Tuxedo Java EE server config, and Geomagic 3D CAD - all unrelated |
| Released | late 1990s (Zoom modem/router firmware era) |
Community Q&A
asked by usersNo questions yet - be the first to ask about ICF files.
