This read-only value returns the next available index to use when creating a new entry in the DNS server list table, or zero if no valid index is available, and also returns zero when queried as the lexicographic successor during a GETNEXT/GETBULK walk to avoid unintended index allocation; successive GETs typically return different values to avoid collisions between concurrent management clients. An admin's management application reads this immediately before creating a new DNS server table entry, to obtain a safe, unused index for the new row. For example, a management script would GET this object to obtain index 5, then create a new DNS server list entry using that index, avoiding a collision with another script doing the same thing concurrently.