[c-nsp] how to stop async radius auth request

[Min Qiu]

Hi,

I configured the aux port of the 26xx to the console of another 
equipment.  The configuration is:

  aaa authentication login default group radius local
  aaa authentication login localauth local
  aaa authorization exec default group radius if-authenticated
  aaa accounting exec default start-stop group radius
  aaa session-id common
  ...
  line aux 0
   modem InOut
   transport input all
   transport output telnet
   stopbits 1
  ...

The problem is the 26xx send radius auth request every 5 seconds:

  rad_recv: Access-Request packet from host 10.2.3.4:1645, id=39,
  length=79
        User-Name = "s Verification"
        User-Password = ""
        NAS-Port = 65
        NAS-Port-Type = Async
        Calling-Station-Id = "async"
        NAS-IP-Address = 10.2.3.4

Is there anyway to stop the async radius auth request?

Thanks,

Min