If only radius-server source command is
configured, executing display
radius-server configuration command could display information on the source
interface that transmits radius packets.
If
radius-server source is not configured, radius packets will carry the IP address
of uplink interface.
If multiple uplink interfaces exist, the IP address of interface
which is selected for the route of packet to radius will be chosen as the source
address. At this time, it will cause that the packets transmitted to radius
carry different IPs. So we suggest that configure Loopback interface
ip-address as radius source if multiple uplink interfaces
exist.