Why don’t the MetaDefender Optical Diode interfaces "diode1" and "diode2" show TX/RX statistics?

Symptom / Question

In the Optical Diode management UI, the interfaces diode1 (transmit) and diode2 (receive) appear under Advanced → Networking → Interfaces, but:

• They do not display TX/RX packet or byte counters
• Administrators want to know whether this is expected and whether the optical channel exposes any traffic statistics (throughput, frames, signal metrics, etc.)

Short answer

• Yes, it is expected that diode1 and diode2 do not show per-interface TX/RX counters.
• The optical link is a hardware-enforced, one-way, non-routable channel, and its internal packet-level statistics are not exposed in the UI.
• Monitoring is intended to be done at higher layers (streams, file transfers, system performance counters, SNMP/PI tags), not at the raw optical interface level.

Why there are no TX/RX counters on diode1 / diode2

1. Unidirectional, non-routable design MetaDefender Optical Diode connects the BLUE (source) and RED (destination) zones using a single optical fiber that carries data in a non-routable, one-way protocol.

   • Data flows only from BLUE to RED.
   • No MAC or IP information is exchanged across the optical channel.

This design is central to the security model and is explicitly described in product documentation and datasheets.

2. Optical link is not treated as a normal NIC The Advanced → Networking section is intended to show IP interfaces, routes, and related settings for the appliance OS networking stack (management/data NICs).

The optical path (diode1/diode2) is:

- A specialized hardware channel, not a standard Ethernet/IP interface. - Used internally by the appliance to move application-level payloads from BLUE to RED. - Not exposed with typical NIC statistics (TX bytes, RX bytes, errors, etc.) in the UI.

As a result, seeing blank or missing TX/RX counters for diode1 and diode2 is normal and by design, not a malfunction.

3. Security & simplicity of exposure Because the diode is a deterministic isolation device—meant to strictly enforce one-way flow and prevent any leakage of network-level information—its design deliberately avoids exposing low-level link details beyond what is required for operations.

Instead of treating the optical link as a router/switch port with SNMP-style interface counters, the product exposes:

- Diagnostics tools (ping, TCP connect, route, etc.) for regular network interfaces. - High-level system and process statistics under Advanced → Statistics (Processes, File System, Memory, System Counters).

What statistics are available for the Optical Diode?

Even though diode1/diode2 do not show TX/RX counters, you can still monitor performance and health:

1. System statistics in the Web UI Under Advanced → Statistics, you can view information on:

   • Processes
   • File system usage
   • Memory statistics
   • System counters

These give an overview of appliance health and performance rather than per-port optical metrics.

2. Stream / transfer-level monitoring Depending on the configured use case (file transfers, database replication, telemetry, etc.), you can monitor:

   • Whether streams are active and successfully transferring data
   • Effective throughput at the application level (e.g., file transfer performance, protocol-specific stats)

Product documentation and integration guides focus on throughput options and supported transfer modes (100 Mbps, 1 Gbps, 10 Gbps, etc.) rather than raw optical port counters.

3. External monitoring via SNMP / PI tags For operational monitoring, the diode supports exposing status and performance metrics to external monitoring systems:

   • Knowledge-base articles describe how to export status/performance metrics of NetWall/Data Diodes using AVEVA PI tags, allowing operators to track health and throughput over time.

These mechanisms are the recommended way to monitor diode performance, instead of relying on per-interface TX/RX counters.