Written by Miloslav Bien, Monday 4 May 2026

The latest ICR-OS release is here. Version 6.6.1 brings a focused set of stability fixes and incremental enhancements to Advantech cellular routers. As with all new releases, routers leaving our production line will come pre-installed with this firmware.

What Changed?

1. VXLAN Tunnel Support Introduced: Create isolated Layer 2 networks that span multiple sites using VXLAN tunnels. This enables seamless connectivity between geographically distributed offices or data centers, allowing devices on separate physical networks to communicate as if they were on the same local network.

2. Dynamic DNS Functionality Extended: Added support for RFC 2136 DDNS and HTTPS transport to the Dynamic DNS. RFC 2136 enables secure, standards-compliant DNS record updates directly from the device, while HTTPS transport ensures these updates are encrypted in transit.

3. LLDP Service Implemented: Automatically discover neighboring network devices with the new Link-Layer Discovery Protocol service. LLDP makes it easier to map and document your network topology, speeds up troubleshooting by identifying connected devices and their capabilities, and improves interoperability with switches, routers, and other infrastructure from any vendor.

4. Web Administration User Experience Improved: Moved Factory Reset to its own page, widened firewall address fields for full IPv4/IPv6 display, added WAN IP and IPv6 addresses for backup routes and moved the Connections list link to the main menu.

5. IPsec Tunnel Configuration and Stability Updated: Modified Key Lifetime to strictly control rekeying and IKE Lifetime to strictly control reauthentication, and resolved a stability issue with IPsec tunnels using multiple subnets when Separate Child SA for Each Subnet is enabled.

6. GNSS SNMP Reporting: Fixed an issue with GNSS data not reporting correctly via SNMP.

7. MBIM on ICR-4261: Fixed MBIM communication failure with the RM520N-GL module.

More Details?

For a full breakdown of the advancements and changes in this release, we encourage you to review the official Release Notes.

Ready to update?

The firmware is available on the Firmware and Router Models pages, or can be downloaded directly to the router from Advantech's public server. For version-specific compatibility details, see the Firmware Compatibility Chart.