Troubleshooting for 802.1X (Dot1X) Authentication Fails on Omada Switch

Contents

Objective

Requirements

Introduction

Troubleshooting Steps

Conclusion

Objective

If you encounter the issue of devices unable to authenticate successfully after configuring the 802.1X feature on the Omada Switch, you can follow the troubleshooting steps below to resolve the problem.

Requirements

• Omada Smart, L2+ and L3 switches
• Omada Controller (Software Controller / Hardware Controller / Cloud Based Controller, V5.9 and above)

Introduction

The 802.1X protocol controls a user's access to the network and prevents unidentified or unauthorized users from transmitting and receiving data.

Troubleshooting Steps

Step 1. Check the Dot 1X authentication global configuration.

Go to Settings > Authentication > 802.1X, where you can see that the 802.1X function has been enabled and the EAP protocol has been selected.

For the authentication protocol, the Omada Switch supports both EAP and PAP protocols. The main difference between the EAP and PAP protocols lies in the generation and transmission of the encryption key for the user's password information.

In the EAP protocol, the random encryption key used to encrypt the user's password information is generated by the Radius server, and the switch is only responsible for transparently transmitting the EAP packets to the authentication server. The entire authentication process is completed by the authentication server. Using the EAP protocol requires the Radius server to support it.

In the PAP protocol, the random encryption key used to encrypt the user's password information is generated by the device itself, and the switch sends the username, random encryption key, and encrypted password information to the Radius server for the relevant authentication processing. The existing Radius servers generally support the PAP protocol.

It can be seen that the EAP protocol places less pressure on the switch but more on the authentication server, while the PAP protocol is just the opposite. You can choose the appropriate protocol based on your own situation.

Step 2. Check the Dot 1X authentication port configuration.

Go to Settings > Authentication > 802.1X, where you can see the switches that have 802.1X enabled and the ports that have been enabled. In the Controller mode, the Port Control is set to Auto by default.

For user devices that do not support 802.1X function, the corresponding ports need to enable both the 802.1X and MAB functions. Most printers, IP phones, and fax machines do not support 802.1X function. After enabling the MAB function, the switch will send the RADIUS access request to the Radius Server using the user device's MAC address as the username and password.

Step 3. Check the network connectivity.

Make sure the network link between the switch and the Radius Server is normal, and also ensure that the authentication port (usually 1812, but there are exceptions) used by the Radius Server is enabled.

Step 4. Check the Radius Server configuration.

Go to Settings > Profiles > RADIUS Profile to check whether the Radius Server’s IP address, Shared Key, and authentication port are configured correctly.

Step 5. Check the Radius Server Group selected for 802.1X.

Go to Settings > Authentication >802.1X, where you can see the RADIUS Profile selected is the one you saw in Step 4.

Step 6. Check if ACL, IMPB, MAC Filtering, or other security policies are configured.

Step 7. Check the client software.

Make sure the client software is not damaged and the client software version supports the current authentication method.

If the above troubleshooting steps still cannot solve the problem, you can try to replace the client software.

Conclusion

We have now completed the troubleshooting of 802.1X authentication failure.

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