You can use the GrantByDefault property of the IIsIPSecurity object to set how you would like to specify server access. GrantByDefault is a Boolean property which determines whether the default setting is grant all with exceptions or deny all with exceptions. If GrantByDefault is TRUE, then all IP addresses and domains are granted access to the server (with the exception of the list entries of the DomainDeny and IPDeny methods). If GrantByDefault is FALSE, then all IP addresses and domains are denied access to the server (with the exception of the list entries of the DomainGrant and IPGrant methods).
SecObj.GrantByDefault Boolean
<%
Dim SecObj
Set SecObj = GetObject("IIS://LocalHost/W3SVC/1")
'Set permissions to grant access by default.
SecObj.GrantByDefault=TRUE
SecObj.SetInfo
%>
IPDeny, IPGrant, DomainDeny, DomainGrant, IIsIPSecurity