The OT-2 communicates with the Opentrons App via standard HTTP and WebSockets over a network connection. The OT-2 can connect via two available networking interfaces:

  • Wi-Fi

  • USB, via an internal USB-to-Ethernet adapter

Over both interfaces, the robot “advertises” itself to the Opentrons App via multicast DNS (mDNS, also known as Bonjour) so that the app can know which IP address to reach out to for a given robot. 

Firewall requirements

  • mDNS discovery: UDP on port 5353

  • Robot communication: TCP on port 31950

Wi-Fi requirements

The OT-2 can connect to Wi-Fi networks with the following types of security:

WPA2 personal

The OT-2 supports WPA2 personal networks.

WPA2 with EAP / 802.1x (e.g. enterprise and eduroam networks)

The OT-2 supports WPA2 enterprise networks with the following authentication types:

  • EAP-TTLS with TLS

  • EAP-TTLS with MS-CHAP v2

  • EAP-TTLS with MD5

  • EAP-PEAP with MS-CHAP v2


Open (no security)

The OT-2 can connect to open networks, but we don't recommend it, because anyone will be able to access the robot.

The OT-2 doesn't support captive portal networks.

MAC addresses

In some organizations, to get an OT-2 set up on the network, the network administrator might need to know its MAC addresses. (MAC addresses are sort of like serial numbers, and are unrelated to Mac computers.)

You can find your OT-2's wired MAC address and wireless MAC address in the Opentrons App.

Connect to your OT-2 (over either USB or Wi-Fi), and then look in the Connectivity section.

OT-2s aren't physically labeled with their MAC addresses. So, to see them, you'll need to be able to connect through the Opentrons App at least once.

Note: On robot software versions older than v3.20.0, a bug caused the wrong MAC address to show up, sometimes. Make sure that both your Opentrons App and your OT-2 are updated to the latest version.

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