How Do I Fix the RADIUS Server is Not Responding? 2022 Easy Tips

Radius server is a protocol that takes it full name as Remote Authentication Dial-In User Service. It contains a database of usernames and passwords and authenticates its users. However, due to some reasons, it may show the error that reads as “Radius server is not responding”

The Not Responding team Guide provides you best techniques that how to tackle the “radius server is not responding” issue. So let’s get inot it after a brief discussion on the RADIUS Server.

What is RADIUS Remote Access?

With RADIUS, remote access servers communicate with a central server which authenticates users and authorizes their actions.

Why Do We Need a RADIUS Server?

You can use a RADIUS server to manage user profiles and authenticate users on your network, so you have control over who has access. 

This is an excellent way of controlling who has access, as you’ll be able to control the central database where all this information lives!

What is a RADIUS Server for WiFi?

A RADIUS server is a network access control device that can be used to enhance security on your wireless networks. 

It authenticates users and authorizes them as they attempt connections, making sure only authorized devices are allowed through the door into its matrix!

How Does RADIUS Server Authentication work?

When a user tries to connect to the network, the RADIUS server attempts to authenticate the user’s credentials and then either allows or denies access to the network. 

The client attempts to authenticate itself by using the given credentials. 

  • It then sends an Access-Request message with a username and password for verification of identity on behalf of the user account 
  • The RADIUS server uses this information to authenticate users against an external database (such as Active Directory).  
  • When a match occurs, it extracts additional details of that user from its own records and checks if there is any access policy or profile associated with them which might allow for further validation. 
  • If one does exist then MFA will be prompted to an Access-Challenge request sent.
  • The response to the Access-Challenge request along with sending out requests using either OTPs sent via push notifications on mobile phones; these contain numbers used in order to gain entry when entering392. 
  • If everything goes smoothly then access will be granted; however, if there are any issues (such as invalid input) then an Access-Reject message is sent back denying you entry into the system.
  • The Access-Accept message has a Filter ID attribute along with a shared secret. The shared secret is used to identify which RADIUS group the user belongs in, to so they can connect with other network devices. If the RADIUS Client could not verify the Shared Secret, the message is rejected.
  • The Client reads the value of the Filter ID attribute, which is assigned by default to be id-ha0. The RADIUS client then connects users with this specific group using their shared secret and filter criteria set in advance on both ends.

The user can now connect to the network.

How Do I Fix the “Radius Server is Not Responding”?

There are a number of ways and methods to fix the radius server not responding.

Here are some best mentioned below. Try any of them to fix the issue.

  • Double check while you are using User Manager for the Radius Server or not. If you are not using then try to use user manager. This will help you to fix the error.
  • If you were already using user manager and still issue prevailed then please do not increase radius timeout.
  • Try to equalize the timeout to 2 seconds. Now check the router’s log after being log in. Try to use valid and invalid passwords alternatively. You will see the difference. 
  • If you want, you can rearrange the timeout=300ms. Disable the radius debug logging once it get working.
  • To fix the radius server not responding issue, try to increase the timeout. If you do not follow this step, specially using FreeRADIUS V2.x, you may receive “radius server is not responding” messag again and again.

Another tip you can follow to solve the issue is to upgrade to RouterOS v5.4 and then try again.

How Do I Debug my RADIUS Server?

To debug your RADIUS server, 

  • Turn on debugging mode with the following command: $ RADIUSd -X 
  • The server is now up and running; test it by sending some packets. 
  • Please wait for a few seconds before pressing CTRL-C to stop the output.
  • Now, paste the below code into your browser window or tab:  And then press Enter!


This article provided you with the best techniques on the “how to fix the Radius server is not responding” issue. After utilizing these techniques, I hope you have resolved your issue.

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