One MA5200F attaches PPPOE users authentication is Radius authentication. Registered NAS IP on radius is uplink interface address of MA5200F and the device operates normally.
One day MA5200F is optimized. Loopback0 address is configured. However, after it is configured, the authentication of radius users fails.
1. The radius attaches provincial broadband dial-up service. The service of other sites is normal and the problem occurs after the reconstruction. Radius is not problematic.
2. debug radius pac on MA5200F and there are many refuse packets with code＝3. The reason is NAS IP ERROR.
(1) Check radius packet sent by 5200F. The source address of radius packet changes from uplink interface address to loopback address.
(2) Registered address on radius server is uplink interface address.
The authentication of dial-up users fails because of illegal nas ip.
3. Change nas ip of MA5200F as loopback address and the problem is solved.
After adding loopback0 address, the interface address to send radius packet changes loopback0 interface. This interface is not configured on radius server, so the packet is discarded and Radius packet has no response. Users cannot access network.
1. If MA5200F does not configure loopback0 address, the source address of radius is uplink interface address.
2. If MA5200F configures loopback0 address, the source address of radius auto changes as loopback0 address.
For reconstruction and optimization of loopback address of MA5200F, it should be noticed.