modifying virtual attributes warnings

[Phil Mayers]

On 14/09/12 16:34, Phil Mayers wrote:
> On 14/09/12 16:01, Alan DeKok wrote:
>> Phil Mayers wrote:
>>> ...requires the following changes:
>>
>>    Fixed, thanks.
>
> Also, I think this has come up before, but master logs:
>
>
> WARNING: You are modifying the value of virtual attribute
> Virtual-Server.  This is not supported.

Actually I also get

WARNING: You are modifying the value of virtual attribute NAS-Port. 
This is not supported.

...which is odd. Is NAS-Port virtual?