> This page is for Firmware, version 4.0 (default).
> For other versions, use one of these documentation indexes:
> - 4.0 (default): https://docs.ouster.com/sensor-docs/firmware/4.0/llms.txt
> - 3.2: https://docs.ouster.com/sensor-docs/firmware/3.2/llms.txt

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.ouster.com/sensor-docs/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.ouster.com/sensor-docs/_mcp/server.

# Host Networking

> Connect a host machine to an Ouster sensor using DHCP, link-local, or static addressing.

Use this guide to connect your host machine to your sensor for the first time. The sensor must receive an IP address and share a subnet with the host machine. IP assignment can use DHCP, link-local, or static addressing.

Once the sensor has an IP address on the correct subnet, address it by hostname (`os-991234567890.local`, where `991234567890` is the serial number on the sticker on top of the sensor).

> **Note**
>
> DNS Service Discovery text announced by the sensor may provide an incorrect part number corresponding to an internal code. Find the correct part number via the web interface or HTTP API.

The sensor announces itself through mDNS/DNS-SD using service type `_ouster-lidar._tcp` on port `80`. Service text records include `path=/api/v1`, `fw`, `pn`, and `sn` when available.

## Networking Terminology

**IPv4 Address**
A dot-notation address used to communicate with devices on a network, formatted as four octets `xxx.xxx.xxx.xxx` (each 0–255). For example, the host may be `192.0.2.1` and the sensor `192.0.2.130`.

**DHCP (Dynamic Host Configuration Protocol) Server**
A service running on the host, switch, or router that assigns a unique IPv4 address to each connected device.

**Link-local IPv4 Address**
Self-assigned addresses used when no DHCP server is available. Valid only within the directly connected network segment. Range: `169.254.0.0/16`.

**Subnet Mask**
Defines which bits of an IPv4 address identify the network and which identify the host.

|                 | Binary Form                           | Decimal-dot notation |
| --------------- | ------------------------------------- | -------------------- |
| IP address      | `11000000.00000000.00000010.10000010` | `192.0.2.130`        |
| Subnet mask     | `11111111.11111111.11111111.00000000` | `255.255.255.0`      |
| Network prefix  | `11000000.00000000.00000010.00000000` | `192.0.2.0`          |
| Host identifier | `00000000.00000000.00000000.10000010` | `0.0.0.130`          |

> **Note**
>
> The subnet mask can be abbreviated as a prefix length. For example, `/24` = `255.255.255.0` and `/16` = `255.255.0.0`.

**Static IPv4 Address**
A manually assigned address for the host and/or sensor, bypassing DHCP and self-assignment. For example: host at `192.0.2.100/24`, sensor at `192.0.2.200`.

**Hostname**
A human-readable name for the sensor. The hostname is `os-991234567890.local`, where `991234567890` is the sensor serial number.

> **Note**
>
> The `.local` suffix denotes the local mDNS domain. It applies when the sensor is directly connected to the host machine or on the same local network. To reach the sensor on a different domain (e.g., with a supporting DHCP and DNS server), replace `.local` with that domain. For example, on `ouster-domain.com` the sensor is reachable at `os-991234567890.ouster-domain.com`.