Thanks Alan, I have figured out the problem.

On Tue, Jun 5, 2012 at 5:00 PM, Alan DeKok <aland@deployingradius.com> wrote:
C.F. Yeung wrote:
> Have changed the unlang as follow.
>
>         update request {
>                 NAS-Identifier := "new-nas-identifier"
>         }
>
> Tried put it under authorize, pre-proxy or post-proxy, nothing changed.

 So... you didn't follow my instructions.  Rather than READING the
documentation, you tried a bunch of random things.

 See the FAQ for "it doesn't work".

 See "man unlang" for how to update proxied requests.

 This is documented.

 No, I won't cut & paste the relevant documentation here.

 Alan DeKok.
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