# NDI Tools

If NDI devices cannot see each other, connect inconsistently, or connect without showing video, start with the checks below. These steps help confirm that both devices are able to discover each other and communicate correctly over the network.

#### 1. Confirm both devices are on the same network

First, check whether both devices are on the same IP subnet. In many basic network setups, this means the first three parts of the IP address should match. For example, one device might be `192.168.1.25` and the other `192.168.1.40`.

If the devices are on different subnets, NDI discovery may not work unless the network has been set up to support it.

#### 2. Test basic network communication

Make sure each device can reach the other over the network. A simple way to test this is to ping the IP address of the other device. If the ping fails, the issue is likely not specific to NDI. It usually means there is a more general network communication problem that must be resolved first.

#### 3. Check the network profile on Windows

On Windows systems, confirm that the network connection is not set to **Public** in Windows Network and Sharing settings.

A Public network profile can restrict the kinds of traffic and discovery behavior NDI depends on. In most trusted local network environments, using a **Private** network profile is more appropriate.

#### 4. Review NDI Access Manager group settings

If you are using NDI Access Manager, check the **Send Groups** and **Receive Groups** settings on both devices.

For general troubleshooting, both systems should usually be configured consistently. If you are not intentionally using restricted groups, setting both sides to **Public** is a good starting point.

If group settings do not match, devices may not see each other even if the rest of the network is working correctly.

#### 5. Confirm multicast settings match

Check whether **Multicast** is enabled or disabled in NDI Access Manager on both devices. For troubleshooting purposes, both devices should normally be set the same way. If one device expects multicast and the other does not, discovery or stream behavior may not work as expected. If you are not specifically using a multicast workflow, it can also be helpful to test with multicast turned off.

#### 6. Check Discovery Server settings

If your environment uses an **NDI Discovery Server**, make sure both devices are configured to use it correctly. If one device is using a Discovery Server and the other is not, or if the server address is incorrect, NDI sources may not appear properly. If you are not intentionally using a Discovery Server, confirm that both devices are relying on the same normal discovery method.

#### 7. Rule out security software interference

Firewall, antivirus, endpoint protection, and threat-blocking software can interfere with NDI traffic. In some cases, devices may appear to connect, but the video or audio stream is blocked or interrupted. Review any security software on both systems and make sure it is not preventing NDI-related traffic including:

* operating system firewalls
* antivirus or endpoint security tools
* network filtering or threat protection software

#### 8. Compare settings on both devices

As a final check, compare the NDI-related network settings on both systems side by side.

Look for mismatches in the following:

* subnet or IP range
* Access Manager groups
* multicast settings
* Discovery Server settings
* firewall or security configuration

Even when each device appears to be set up correctly on its own, a mismatch between the two can still prevent NDI from working properly.