- The Teradata Vantage gateway tests the incoming IP address against each allow element.
- The filter masks the incoming IP address with the mask from the allow element.
- The filter masks the IP address in the allow element with the same mask.
- If the result for the two masked IP addresses match, the filter identifies the IP address under test as a candidate for approval. The filter then ends the allow phase of testing and begins deny testing of the incoming IP address.
- The gateway tests the incoming IP address against each deny element.
- The filter masks the incoming IP address under test with the mask from the deny element.
- The filter masks the IP address from the deny element with the same mask.
- If the result for two masked IP addresses match, the filter allows the IP address under test to access the database and ends the denial phase of testing.
Although you can construct a restrictive filter using both allow and deny elements, you do not have to use both elements in a restrictive filter. A restrictive filter must contain at minimum either an allow or a deny element. If you use only a single element, it should be the primary element type for the filter type, that is, an allow element in a restrictive filter.