1. The DN Block Self Healing feature enables EPAP users to add new DN Blocks that conflict with an existing DN Block in the EPAP database. The following changes occur when the self healing EPAP database encounters this conflict:

   • Pre-existing/conflicting DN Block is automatically deleted from the EPAP database.
   • New DN Blocks are created successfully with new attributes.
   • Old DN Block are split to create more DN Blocks for the range not covered by new DN block.
2. Upon deletion of the new DN Block, the DN Block Self Healing feature returns a range of numbers to the original DN Block, which was split as a result of addition of new DN Block. This splitting action is described in the previous item.

Error Codes for DN Block Self Healing

These error codes are associated with the DN Block Self Healing feature.

• PDBI_MULTI_DNB_CONFLICT - More than one conflicting DN Block was found in the EPAP dtabase.
• PDBI_DNB_SAME_PROPERTIES - A DN Block with the same properties exists in the database and is a superset of the requested DN Block. Splitting eligibility of a DN Block is not considered a property for this error.
• PDBI_DNB_SPLIT_NOT_ALLOWED - The user is attempting to split an existing DN Block that was specified at the time of its creation or update as ineligible for splitting.
• PDBI_DNB_DLT_NOT_ALLOWED - The user is attempting to delete a fragment of a master range while its subranges are present.
• PDBI_DNB_PARENT_PROPERTY_MISMATCH - The user is attempting to delete fragments of a master range which have differing attributes. Splitting eligibility of a DN Block is not considered a property for this error.

Rules for DN Block Self Healing

The list of rules for the DN Block Self Healing feature are as follows:

• When the new DN Block is a subset of an already existing DN Block with different properties, the old DN Block is split into either 2 or 3 new DN Blocks.
• An error is returned when the new DN Block has bdn and edn the same as an existing DN Block.
• An error is returned when the new DN Block has single DN address.
• An error is returned when the resulting DN Block has single DN address.
• An error is returned when more than one conflicting DN Block exists in the EPAP database.
• When the new DN Block is a subset of an existing block with same properties, the creation of new DN Block is not allowed.
• When the new DN Block conflicts with an existing block and is not its subset, the creation of new DN Block is not allowed.
• An error is returned when the user tries to insert a DN Block that conflicts with a DN Block that has itsa split option set to no.
• An error is returned when the user tries to insert a DN that conflicts with a DN Block that has its split option set to no.
• When a DN Block that was created as a result of splitting an existing DN Block is deleted, the complete DN Block that existed before the split is returned to the EPAP database.

Support for DN Block Self Healing

Table D-1 illustrates whether the DN Block Self Healing is supported (Yes) or prohibited (No) and the corresponding error that is returned.