Hi,
You can't do this with one site. Anonymous is used first before any other
authentication option. When browser (or client) tries to access the website
it will always try anonymous first. If it succeeds then it will load the
page and no authentication options are enforced (if NTFS permissions are set
correctly).
If the IIS website is has disabled Anonymous access it will return Access
Denied to the client and ask it to authenticate with most secure option
first (e.g. Integrated and then Basic if selected).

Signature
Mike
Microsoft MVP - Windows Security
>I have an Intranet site served from IIS6 which I need to allow anonymous
> access to because it gets used by Blackberries. I get header infor from
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>
> Thanks in Advance