Debugging Radius with TCPdump - NCOS-CLI-Introduction-to-TCPdump/Debugging-Radius-with-TCPdump

Introduction to TCPdump
ft:locale
en-US
ft:sourceName
Paligo_Prod
Document Type
Article

Complete the following steps to view Radius debugging information.

  1. Log into NetCloud Manager.

  2. Select Devices in the left-side navigation panel.

  3. Select the desired router.

  4. Select the Remote Connect menu, and then select Console.

  5. Select Open Console.

  6. Enter the following command:

     tcpdump -i [WAN_INTERFACE] -n port 1812

    • Radius uses port 1812 to communicate between the client and the server.

    • Three messages are sent and received during successful negotiation:

      • Access-Request: Sent from the Client

      • Access-Challenge: Sent from the Server

      • Access-Accept: Sent from the Server

    • Example of expected results

      [administrator@INDIA-AER2200: /]$ tcpdump -i vpn-460c9d10 -n port 1812                                   
06:57:17.503672 IP 10.15.0.1.43751 > 172.21.21.93.1812: RADIUS, Access-Request (1), id: 0x14 length: 205                
06:57:17.560852 IP 172.21.21.93.1812 > 10.15.0.1.43751: RADIUS, Access-Challenge (11), id: 0x14 length: 119             
06:57:17.836523 IP 172.21.21.93.1812 > 10.15.0.1.58035: RADIUS, Access-Accept (2), id: 0x18 length: 280