# tt_ethernet_link_up

[<< Home](../index.md) | [<< Metrics](../metrics.md)

## Name

### Prometheus Metric Name

```
tt_ethernet_link_up
```

### Metric Path (tt-telemetry)

Schema:

```
{hostname}/tray{tray}/chip{chip}/channel{channel}/tt_ethernet_link_up
```

Example path:

```
bh-glx-c09u02/tray1/chip2/channel0/tt_ethernet_link_up
```

## Description

Whether the Ethernet link is up on a specific channel. When UMD firmware link status is available (via the ARC telemetry snapshot, firmware 19.9+ on both Wormhole and Blackhole), that firmware-sourced status is used: the firmware reports link status in NOC0 coordinates, which are filtered for harvested cores and translated to logical coordinates to identify this channel. When the firmware-sourced link status is not available, the metric falls back to reading the link-up word directly from device memory (periodically force-refreshed to ensure accuracy). When topology information is available (via Factory System Descriptor), additional labels provide details about the physical port and remote endpoint.

## Values

**Type:** Boolean

**Units:** None

**Allowable values:**
- **True (1)**: The Ethernet link is up and operational.
- **False (0)**: The Ethernet link is down.

## Prometheus Labels

|Label Name|Value|
|---|---|
|hostname|The host from which the metric was collected.|
|hall|The datacenter hall where the host is located. Sourced from the Factory System Descriptor (FSD).|
|aisle|The datacenter aisle where the host is located. Sourced from the Factory System Descriptor (FSD).|
|rack|The rack number where the host is located. Sourced from the Factory System Descriptor (FSD).|
|shelf_u|The shelf U position in the rack where the host is located. Sourced from the Factory System Descriptor (FSD).|
|tray|The tray (UBB) that the device is located on.|
|chip|The ASIC location within the tray.|
|channel|The Ethernet channel number on the chip.|
|port_type|The physical port type (e.g., QSFP, backplane). Present when topology information is available.|
|port_id|The physical port ID. Present when topology information is available.|
|remote_hostname|The hostname of the remote endpoint. Present when remote endpoint information is available.|
|remote_tray|The tray number of the remote endpoint. Present when remote endpoint information is available.|
|remote_chip|The ASIC location of the remote endpoint. Present when remote endpoint information is available.|
|remote_channel|The Ethernet channel of the remote endpoint. Present when remote endpoint information is available.|
|remote_hall|The datacenter hall of the remote endpoint. Present when remote endpoint information is available.|
|remote_aisle|The datacenter aisle of the remote endpoint. Present when remote endpoint information is available.|
|remote_rack|The rack number of the remote endpoint. Present when remote endpoint information is available.|
|remote_shelf_u|The shelf U position of the remote endpoint. Present when remote endpoint information is available.|